Datasets:

Daniel-P-Gonzalez
/

CCOpenBooks

Dataset card Viewer Files Files and versions Community

Split (1)

train · 6.17k rows

text stringlengths 313 1.33M
# Japanese/Dialects ``` !A map of Japanese copula.{width="320"} Many learners of Japanese begin their studies thinking that the language is a single standard, spoken across the whole nation. While it is true that nearly all Japanese nationals can speak the standard language, it is by no means their every day language. This long and mountainous archipelago has over the centuries given rise to a great number of dialects with their own distinct accent, intonation and vocabulary. Before the Tokugawa Shogun (徳川将軍) moved to Edo (江戸, modern day Tokyo) in 1603, the main place of government was Kyoto (京都), and standard Japanese was the ancestor of today\'s Kyoto dialect. Modern standard Japanese, hyōjungo (標準語) is basically the dialect of Tokyo. This is used in schools and media throughout the country. Other varieties of Japanese are often considered provincial and like in every language, each bears connotations of archetypes. !A map of Japanese dialects.{width="320"} ## Eastern Japanese - Hokkaidō Dialect - Tōhoku Dialect - Northern - Tsugaru Dialect - Southern - Kantō Dialect - (Japanese/Dialects/Yokohama?) - Tōkai Dialect - (Japanese/Dialects/Mikawa) - Hokuriku Dialect - Japanese/Dialects/Ishikawa - Japanese/Dialects/Toyama ## Western Japanese - Hokuriku Dialect (Talk:Japanese/Dialects/Ishikawa?) - (Japanese/Dialects/Toyama) - Kinki (Kansai) Dialect - Japanese/Dialects/Osaka - Chūgoku Dialect - Umpaku Dialect - Shikoku Dialect - Kyūshū - Hōnichi Dialect - Hichiku Dialect - Satsugū Dialect ## Hachijō Island - Hachijō Dialect ## Ryūkyū - (Japanese/Dialects/Okinawa?)
# Japanese/Kana chart ---------------------------------------- ------------------------------ Base Kana (clear sounds) Compound sounds あ *a* アい *i* イか *ka* カき *ki* キさ *sa* サし *shi* シた *ta* タち *chi* チな *na* ナに *ni* ニは *ha* ハひ *hi* ヒま *ma* マみ *mi* ミや *ya* ヤら *ra* ラり *ri* リわ *wa* ワゐ \'\'wi\'\' ヰん *n* ン Voiced consonants (turbid sounds) Turbid compound sounds が *ga* ガぎ *gi* ギざ *za* ザじ *ji* ジだ *da* ダぢ *ji* ヂば *ba* バび *bi* ビ Stop consonants (half turbid sounds) Half turbid compound sounds ぱ *pa* パぴ *pi* ピ ---------------------------------------- ------------------------------ : ひらがな - Romaji - カタカナ ------------- Miscellanea っッ ------------- `<small>`{=html}The grayed kana are no longer applicable in standard Japanese, but still may be encountered within certain contexts, for example older names and works of fiction.`</small>`{=html} ## External Links - Kana Copybook (PDF) --- Memorize the Kana through handwriting.
# Japanese/Vocabulary ## Elementary vocabulary - /Colors/ - /Clothes and accessories/ - /Animals/ - /Numbers/ - /Time/ and dates - Directions - Food and drink - /Sushi/ - /Body parts/ - /Family and people/ - Weather and seasons - /Verbs/ - /Adjectives/ ## Proper - Countries and languages - Regions and prefectures of Japan ## Specialized - /Academic Subjects/ - /Astronomy/ - /Biology/ - /Chemistry/ - /Glaciology/ - /Mathematics/ - /Linguistics/ - /Law/ - /Aviation/ - /Business/ - /Banking/ - /Computing/ - /Health/ - Government and politics - /Punctuation/ - /Vocations/ - /Units/ ### Cultural - /Music/ - /Videogame/ ## By origin - /Gairaigo/ - /Onomatopoeia/ bn:জাপানি ভাষা শিক্ষা/অভিধান
# Japanese/Grammar ## Word order Japanese is a SOV (Subject-Object-Verb) language. English is typically SVO (Subject-Verb-Object). In Japanese, the verb always appears at the end of clauses and sentences. Japanese parts of speech are usually marked with words called \"particles\" that follow the word they modify. These particles identify the word\'s or phrase\'s function in the sentence---for example, topic, subject, direct/indirect object, location of action, etc. Japanese is flexible in terms of word-order due to use of particles. Sentences, however, generally have the following structure: : Sentence Topic, Time, Location, Subject, Indirect Object, Direct Object, Verb. ## Context sensitivity Japanese is highly context-sensitive. Words or phrases obvious to both the speaker and listener are often omitted. It could be considered a \"minimalist\" language. For example, the statement: \"I\'m going to watch a movie.\" could be translated as 「映画を見る。」 (eiga o miru.); literally, \"Movie watch.\" \[I\] is implied, as it is the speaker who is making the statement. Depending on the context, however, this phrase could also be translated as \"s/he is going to watch a movie\", \"we will watch a movie\", etc. Japanese has many levels of formality and depends not only on what is said, but also on who is saying it and to whom. The language is socially striated to the point that different forms of speech exist for men and women. ## Parts of speech Japanese parts of speech, although no more complicated than those of other languages, do not fit well into typical labels such as verb, noun, and adjective. Keep that in mind over the course of your studies. ### Nominals #### Nouns Nouns in Japanese are fairly immutable. They do not take definite or indefinite articles, gender, and do not change for number. Although there is no true plural in Japanese, a small number of nouns may take one of several collective suffixes. : Tanaka-san (Mr. Tanaka), Tanaka-san-tachi (Mr. Tanaka and his group) Certain nouns may take a prefix in polite speech. Most often, native Japanese words (和語) are preceded by \"o-\" (\"お\"), and Sino-Japanese words (漢語) are preceded with \"go-\" (\"ご\"). Both are readings of the kanji \"御\". Though primarily used for adding politeness or distance, some words more commonly appear with the prefix than others, and in some cases, never appear without it (e.g., お茶 \[ocha\], \"green tea\"). Many nouns may be converted into verbs simply by affixing 「する」 (suru) to the end. : \"benkyō\" () is a noun meaning \"study/studies\" while \"benkyō-suru\" () is the verb \"to study\". Nouns may also function as adjectives when the particle の (no) or な (\"na\") is appended. : \"ki\" (木) means \"wood\" with \"ki no tatemono\" (の) meaning \"wooden building\". #### Pronouns Unlike many other languages, Japanese has no true pronouns; since words that are clear from context are usually elided, there is less need for them. In general, natural-sounding Japanese tends to avoid the use of nouns that refer to people except when explicitly needed. This is often a point of confusion for beginners. Pronominals are not grammatically distinct from ordinary nominals: notably, they may take adjectives, which pronouns cannot. : \"watashi\", \"boku\", \"ore\", \"watakushi\" all mean \"I\"; and \"anata\", \"kimi\" mean \"you\" #### Na-adjectives A Na-adjective is a nominal that often precedes a copula (such as \'na\'). Due to the common occurrence of na-adjectives, many Japanese dictionaries write nominals with the \'na\' included. Na-adjectives are generally adjectival in meaning, as most cannot exist in context without a previously denoted subject; however, one might simply say \"げんき　な (genki na)\" to describe a subject that is understood within the current conversation\'s context (this situation is limited to casual or somewhat informal conversation; using full sentences is almost always necessary when speaking to anyone of higher status). Examples of na-adjectives: \"heta na:\" unskilled, bad at; \"genki na:\" healthy, energetic; \"orijinaru na:\" original ### Verbals #### Verbs Verbs are where most of the action in Japanese sentences takes place. They are the primary means for controlling levels of politeness in speech,... Japanese verbs inflect directly for tense, negation, mood, aspect, politeness, and honorific speech. Unlike English, conjugation of Japanese verbs is extremely regular, with few exceptions. The system takes some getting used to, but once the kana have been learned, a uniform pattern emerges. Verbs are placed into one of three groups: 五段 (godan, aka Type I), 一段 (ichidan, aka Type II), and 不規則 (fukisoku, irregular). Only two verbs are generally considered irregular in the modern language, 来る (kuru, to come) and する (suru, to do). Despite being such, even they are somewhat regular in their irregularity. #### I-adjectives These inflect for tense, politeness, and honorific speech as well (although not aspect or mood, as they are all stative verbs); an -i adjective will always end in -ai, -ī, -ui, or -oi. (Note that there are also stative -u verbs.) : \'\'\"utsukushī\": beautiful; \"ī\": good; \"sugoi\": amazing; \"ureshī\": happy #### The copula Although the copula is not strictly a verb, most of its forms derive from \"de aru\", but inflects somewhat irregularly. It retains an \"attributive form\", na, used to modify the noun it stands before: however, this form is almost exclusively used after na-adjectives. ### Other Particles: Also called postpositions or joshi, particles show the case of nouns in Japanese: that is, they mark nouns as being the subject, object, indirect object, etc. (English typically uses word order or prepositions for the same effect.) Particles follow the noun they modify. - wa (は): topic - ga (が): subject - o (を): direct object - no (の): possession, apposition - ni (に): indirect object, direction \"to\", location of existence, etc. - kara (から): direction \"from\" - made (まで): \"until\", \"as far as\" - de (で): means, location of an action Some particles are used after sentences instead: - ka (か): question marker - yo (よ): marker for giving new information or showing emphasis or certainty - ne (ね): marker for seeking agreement - tte (って): informal quotation marker Adverbs: Adverbs typically modify the entire sentence, although most Japanese quantifiers (including numbers) are actually adverbs, rather than adjectives as in English. - aikawarazu as always; - sukoshi (少し) a little, few - mō sugu soon, before long; - sō thus, so Conjunctions: Japanese conjunctions typically either apply to nominals (like English \"except\") or to predicates (like English \"when\"), not both (like English \"and\"). - mata wa or (n.); - soshite (そして) and then, and also (pr.); - ga but (pr.) Interjections: Common to every language. - wā! \"wow!\" - are? \"huh?\", \"wha?\" - ē to \"um, er\" - anō \"um\" ## Sentence examples ------- 遅い Osoi. late ------- \[You\'re\] late. -------- ----- 綺麗だ Kirei da. Pretty is -------- ----- : \[It\] is pretty. ------ --------- ------ ------- これは本です Kore wa hon desu. This topic book is. ------ --------- ------ ------- : This is a book. ---------- --------- ------------ 富士山は美しい Fuji-san wa utsukushī. Mt. Fuji topic beautiful ---------- --------- ------------ : Mt. Fuji is beautiful. ------- --------- -------- ----------------- ------- 今日はあまり寒くないです Kyou wa amari samuku-nai desu. Today topic very cold-NEG-POLITE is ------- --------- -------- ----------------- ------- : It\'s not very cold today. / Today isn\'t very cold. ----- ---------- ---------------- 海を見ました Umi o mimashita. Sea object look at-past ----- ---------- ---------------- : \[I\] gazed out at the ocean. ---------- --------- ------- ---------------- ------------------ お母さんは店に行きました Okāsan wa mise ni ikimashita. Mother topic store place/method went-PAST-POLITE ---------- --------- ------- ---------------- ------------------ : \'\'\[Her\] mother went to the store. -------- ----------- ------------------ 夏が来ました Natsu ga kimashita. Summer subject come-PAST-POLITE -------- ----------- ------------------ : Summer has come.
# XForms/Examples Wanted Here are some examples were are still looking for: ## Examples Wanted Here is list of the example progams we are looking for in rough order of priority (highest priority examples are first) 1. Example to format currency - We would like an example that formats based on numeric picture formats such as \"\$#,###.##\". 2. Validate Field by Character Set - We would like to validate a field base on a pattern character set. So for example we would like to mark a field invalid if it has special characters such as non-alpha or non-numerics. How do you specify this in a binding rule? Can you bind it to an XML Schema data type? 3. Full CRUD Example on dynamic file Demonstrate the full create, read, update delete (CRUD) cycle for some form data selected from a file local file system. The example load the form data from a file (use the upload control) into an instance document and (similar to using the src=\"\" attribute), view the data, edit the data and save the data back to a file using a submit to a file. For doing this on a static file see ../Read and write with get and put/ 4. Display required elements from Schema - A XML Schema file can tell you exactly what fields are required (if the minOccurs is not zero). Demonstrate how these fields can be automatically be displayed using CSS and the :required pseudo element 5. Instance validation - An example based on an external XML schema. Validate an instance using the XML Schema file. ../Validate/ 6. XMLEvents Demonstrate how XML Events work with event propagation. Show how events bubble up the event responder tree. 7. Use industry standard forms (IRS tax forms, ACORD insurance forms etc). 8. A XForms example incorporating XML Signing in XHTML preferably with digital filters too. 9. Full CRUD Example using any Database Demonstrate the full create, read, update delete (CRUD) cycle for some form data selected from a database. The example load the form data from a database into an instance document and (similar to using the src=\"\" attribute), view the data, edit the data and save the data back to a database using a submit ## Non FireFox Examples FireFox does not have Pseudo_element_support for `<b>`{=html}`::value``</b>`{=html}, `<b>`{=html}`::repeat-item``</b>`{=html}, and `<b>`{=html}`::repeat-index``</b>`{=html}. See Pseudo element support in FireFox Are their any other systems that will support this that we can get examples from? ## Finished Examples 1. Get information from an XHTML web page - use the instance src to extract a value from an XHTML file. See ../Read and write with get and put/ 2. Web Service Examples using REST - Examples of calling a web service using the simplified REST protocol where web service arguments are just passed in a URL. See ../Search flickr and ../Search Amazon 3. Call a web service from a form using the submit command. We would like an example that does not require the students to register to use a web service. See ../Web service/ 4. ../Load from XML Schema - Load an XML Schema and use the data types in the XML Schema to validate data types in a form. 5. ../Facet Validation/ - We would like to have a family of example programs that validate based on the facets of an XML Schema file but it appears that the FireFox extension does not yet support facet validation (restrictions based on length, minLength, maxLength, etc) so this is somewhat difficult to demonstrate easily in a classroom setting when the students are just running the FireFox browser. 6. Set textarea size. Use the CSS to set the area of a textarea size differently of many boxes. See ../Textarea with style/
# XForms/Conditional Actions ## Motivation You want to conditionally perform an action based on an XPath Expression. ## Method We will use the if attribute of an action that is part of the XForms 1.1 specification. We will set up an event that will be triggered every time an instance becomes empty. We will create an action and set the observer attribute to watch for changes in the people instance. Here is the code for the action itself: ``` xml <xf:action ev:event="xforms-delete" ev:observer="people" if="not(person)"> <xf:insert origin="instance('person-template')" context="."/> </xf:action> ``` This says to watch the people instance and if there is not a person in the people instance then insert one using the person-template instance. ``` xml <html xmlns="http://www.w3.org/1999/xhtml" xmlns:xf="http://www.w3.org/2002/xforms" xmlns:xsd="http://www.w3.org/2001/XMLSchema-datatypes" xmlns:ev="http://www.w3.org/2001/xml-events"> <head> <title>Test of populating a repeat if it becomes empty</title> <xf:model id="m"> <xf:instance id="people"> <people xmlns=""> <person> <name>John</name> <email>j...@example.org</email> </person> <person> <name>Bethany</name> <email>beth...@example.org</email> </person> </people> </xf:instance> <xf:instance id="person-template"> <person xmlns=""><name/> <email/></person> </xf:instance> </xf:model> </head> <body> <h1>Test of populating a repeat if it becomes empty</h1> <xf:group ref="instance('people')"> <xf:repeat nodeset="person"> <xf:input ref="name"><xf:label>Name: </xf:label></xf:input><br/> <xf:input ref="email"><xf:label>Email address: </xf:label></xf:input> <xf:trigger> <xf:label>Delete</xf:label> <xf:delete ev:event="DOMActivate" nodeset="."/> </xf:trigger> </xf:repeat> <xf:action ev:event="xforms-delete" ev:observer="people" if="not(person)"> <xf:insert origin="instance('person-template')" context="."/> </xf:action> </xf:group> </body> </html> ``` ## Acknowledgments This example was posted on the Mozilla XForms newsgroup by John L. Clark in December 10th of 2008.
# XForms/A Trigger for Inserting BBcode into a Textarea box ## Using Trigger to Add BBcode or Other Text to Input or Textarea Controls Here is a simple way to use a button (trigger) to add commonly used text to your xforms-input or xforms-textarea controls. This could be many things such as BBcode (bold/unbold codes), date-time stamps, frequently used formatted text such as a letterhead, signature blocks, special codes that aren\'t easy to remember\-- all depending on the purpose of your form and your specific needs. ## Link to working XForms Application Load Example XForms Application A more advanced example for inserting at the beginning or end of text (with some additional code inserts such as links and images) Load Example XForms Application ## Program Structure For simplification, we are using a single `<text/>`{=html} element in our model/instance to hold our example input. The style is not really necessary other than to give one a larger text area to test with. The real power, and simplicity, of the form is in the value attribute of the xforms-setvalue element which itself is placed inside an xforms-trigger: ` value="concat(//text,'whatever you desire goes here')"` ## Sample Program ``` html <html xmlns="http://www.w3.org/1999/xhtml" xmlns:xf="http://www.w3.org/2002/xforms" xmlns:ev="http://www.w3.org/2001/xml-events"> <head> <title>Insert BB code</title> <style type="text/css"> <!--mozilla specific style--> @namespace xf url('http://www.w3.org/2002/xforms'); xf\|textarea .xf-value{ width:25em; height:20ex; } </style> <xf:model> <xf:instance> <data xmlns=""> <text/> </data> </xf:instance> </xf:model> </head> <body> <xf:trigger><xf:label>Bold</xf:label> <xf:action ev:event="DOMActivate"> <xf:setvalue ref="//text" value="concat(//text,'[b][/b] ')"/> <xf:setfocus control="textArea"/> </xf:action> </xf:trigger><br/> <xf:textarea id="textArea" ref="//text"> <xf:label>Post:</xf:label> </xf:textarea> </body> </html> ``` ## Discussion This solution will only append the inserted code/text to the end of the current text in the text box. To have it always at the beginning, simply change the order of the arguments in your concat function (see the second example link above). Limitation: This solution cannot insert code/text into the middle of the current text in the text box. You can use html entities to do complex formats like a letterhead (if you need to preserve space or bold etc..) (!!note: the ampersand-& is replaced by the percent-% as I couldn\'t figure out how to escape html entities in this wikibook) ``` xml <xf:setvalue ref="//text" value="concat(//text,' %lt;div xmlns=%quot;http://www.w3.org/1999/xhtml%quot;%gt; %lt;p%gt;%lt;b%gt;Testing insert with HTMLentities%lt;/b%gt; %lt;/p%gt; %lt;p%gt;%lt;i%gt;Testing Insertwith HTMLenitites%lt;/i%gt; %lt;/p%gt; %lt;pre%gt; Indent Here%lt;/pre%gt; %lt;/div%gt;')"/> ``` In such a case, make sure your xforms-output has a mediatype attribute like so: ``` xml <xf:output ref="//text" mediatype="application/xhtml+xml"/> ``` ## Discussion
# XForms/SVG ## Motivation You want to dynamically load and render SVG. ## Sample Program ``` html <html xmlns="http://www.w3.org/1999/xhtml" xmlns:ev="http://www.w3.org/2001/xml-events" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xf="http://www.w3.org/2002/xforms" xmlns:svg="http://www.w3.org/2000/svg"> <head> <title>SVG Browser</title> <style type="text/css"> #svgimg .xforms-value { width: 400px; min-width: 400px; height: 400px; min-height: 400px; } </style> <xf:model> <xf:instance id="current"> <current xmlns=""/> </xf:instance> <xf:instance id="names"> <names xmlns=""> <name fname="mozilla.svg">Mozilla</name> <name fname="wii.svg">Wii</name> <name fname="duke.svg">Duke</name> <name fname="git.svg">Git</name> <name fname="cartman.svg">Cartman</name> <name fname="tiger.svg">Tiger</name> <name fname="gcheck.svg">GCheck</name> <name fname="pencil.svg">Pencil</name> <name fname="python.svg">Python</name> <name fname="ietf.svg">IETF</name> <name fname="osgr_pie.svg">OSGR Pie</name> </names> </xf:instance> <xf:instance id="inlinesvg"> <svg xmlns='http://www.w3.org/2000/svg'/> </xf:instance> <xf:submission id="loadsvg" method="get" replace="instance" instance="inlinesvg" serialization="none" mode="synchronous"> <xf:resource value="concat('svg/',.)"/> </xf:submission> <xf:action ev:event="xforms-ready"> <xf:setvalue ref="." value="instance('names')/name[1]/@fname"/> <xf:send submission="loadsvg"/> </xf:action> </xf:model> </head> <body> <h1>SVG Browser</h1> <xf:select1 ref="." appearance="minimal" incremental="true"> <xf:label>Select SVG: </xf:label> <xf:itemset nodeset="instance('names')/name"> <xf:label ref="."/> <xf:value ref="@fname"/> </xf:itemset> <xf:send ev:event="xforms-value-changed" submission="loadsvg"/> </xf:select1> <xf:trigger> <xf:label>Next</xf:label> <xf:setvalue ev:event="DOMActivate" ref="." value="if( instance('names')/name[ preceding-sibling::name[1]/@fname = current() ], instance('names')/name[ preceding-sibling::name[1]/@fname = current() ]/@fname, instance('names')/name[1]/@fname)"/> </xf:trigger> <br/> <xf:output id="svgimg" value="xf:serialize(instance('inlinesvg'))" mediatype="image/svg+xml"/> </body> </html> ``` ## Credits This was created by Alain Couthures on the XSLTForms mailing list. A working copy can currently be found on the AgenceXML web site.
# XForms/FireFox Extension ## Motivation Your users all can run the FireFox browser on MS-Windows and you want very fast XForms loading. ## The Mozilla Firefox Plugin This plugin was developed over several years with the support of IBM and Novell. It is now obsolete and is no longer supported. The official version is available from addons.mozilla.org. Nightly and other (testing) builds are available at Philipp Wagner\'s Web Site ## References - Mozilla FireFox XForms page Note that this web page was last updated in April 14th, 2014. ## Discussion
# XForms/Picoforms ## Getting XForms to work with Picoforms Picoforms is commercial XForms client that is designed to work with mobile phones and IE 6.0 as a plugin. To get IE to see the forms you have to do the following: If your forms are stored in the server with an XHTML extension you must 1. Make sure that IE knows to render .XHTML files as html file types. This can be done by using the registry edit tool. 2. Add the following processing instruction for picoforms AFTER the html element ## IE 6.0 Registry MIME-Type Fix To change the IE registry to allow IE to know that .xhtml files should be rendered as html. To do this do the following. From the Windows start menu click Start/Run. Enter \"regedit\" and press enter. Use the Registry browser to navigate to the HKEY_CLASSES_ROOT folder and then find the MIME/Daatabase/Content Type folder. From their add the following: Binding for xhtml files: [HKEY_CLASSES_ROOT\MIME\Database\Content Type\application/xhtml+xml] "CLSID"="{25336920-03F9-11cf-8FD0-00AA00686F13}" "Extension"=".xhtml" "Encoding"=hex:08,00,00,00 Binding for xq files: [HKEY_CLASSES_ROOT\MIME\Database\Content Type\application/xhtml+xml] "CLSID"="{25336920-03F9-11cf-8FD0-00AA00686F13}" "Extension"=".xq" "Encoding"=hex:08,00,00,00 The CLSID above is for HTML rendering. You can copy this from the .htm MIME-type. If you want it to render in xml use the binding for XML files. ## Sample HTML Header ``` xml <html xmlns="http://www.w3.org/1999/xhtml" xmlns:xf="http://www.w3.org/2002/xforms" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:ev="http://www.w3.org/2001/xml-events" > <?import namespace="xf" implementation="#default#pxf"?> <head> ... ``` Note that if you are using eXist to generate your forms you need to put the PI inside braces and serialize as html. ``` xml declare option exist:serialize "method=html media-type=text/html indent=yes omit-xml-declaration=yes"; ... <html xmlns="http://www.w3.org/1999/xhtml" xmlns:xf="http://www.w3.org/2002/xforms" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:ev="http://www.w3.org/2001/xml-events" > {<?import namespace="xf" implementation="#default#pxf"?>} <head>... ``` Also, make sure if you make changes you should be sure to use SHIFT-reload to clear the IE cache. ## CSS Issues Note that IE6 does not recognize the \@namepsace directive in CSS files. These CSS files will need to be converted use xf\\: instead of the CSS \\| standard. ## References Picoforms Web Site
# XForms/Best practice This cookbook identifies example programs that demonstrate best practices. An XForms Best Practice is a specific way of solving a general problem that has been selected from among posible solutions by various authors. There are a variety of reasons for best practices but in general best practices increase program modularity, maintainability and flexibility. The following logo will appear next to sample programs that constitute a best practice: ![](XForms-best-practice.jpg "XForms-best-practice.jpg"){width="50"}. These should also be some reason in each example why this solution is usually preferred by developers over other solutions as well as give some indication of why this may not be appropriate in some situations. Although a best practice is usually the preferred way of solving a given problem, it is not always the right choice for all circumstances. For example developers frequently put a style sheet in an external file but if you are doing training and want the example to contain the CSS file, there are good reasons to put the CSS file directly in the html header.
# XForms/Debugging Tips If you are a newcomer to XForms and you are having problems debugging XForms you are not alone. XForms debugging can be tricky especially for newcomers. If you follow the newsgroups on XForms you will see several problems come up frequently. ## Common Problems These problems, roughly sorted in terms of frequency include the following: 1. Make sure to name your files with the `<b>`{=html}`.xhtml``</b>`{=html} extension. Many browsers including FireFox do not look for XML tags in files with the .htm or .html extension. 2. Problems related to forgetting to associate instance data with a namespace or the default namespace. This can be fixed by adding the `xmlns=""` parameter to your instance variable 3. Incorrect or missing namespaces in the body of a document. For example, if the default namespace is html the tag `<input>`{=html} is valid but the browser will look at it as `<html:input>`{=html} not `<xf:input>`{=html}. This happens frequently when users copy XForms example code from places that use XForms as the default namespace. This is a good reason that tutorial and training developers should not use XForms as the default namespace. 4. Incorrect binding between the model and the view. This usually occurs because the \"ref\" or \"nodeset\" attributes are not correctly defined or that the group or repeat changes the path prefix of a data element. 5. Failure to bind to the form to the instance because the XForms processor cannot find one or more instance specific namespaces. If you have customised your XForm with an XSLT or an XQuery before streaming it to your user, the processor might relegated the declaration of some of your namespaces to the instance where they first occur because it treats the contents of the ref and bind attributes on your xform as just content. However, your XForms processor probably expects the definition of the namespaces in your ref attributes to be on the parent axis and may not look in the model instances for any declarations. When this happens you will need to manually construct the root xhtml:html node, explicitly declaring any namespaces that appear in your form. ## Using an XForms Validator Some people have found this XForms validator helpful: <http://xformsinstitute.com/validator> This program will find common errors in XForms examples. ## Using Eclipse to validate XPath There is a nice eclipse plugin for XSLT providing also an XPath validation \"view\". See: <http://wiki.eclipse.org/XSLT_Project> ## Debugging Tools for Firefox One of the most useful Firefox extensions is the XForms Buddy debugger. This tool allows you to visually inspect all of the instances in the model while the XForms are running in the Firefox browser. This is especially useful for ensuring that instance values that are dynamically configured are correctly set by the XForms. The link to the site is: here ## Printing your Bindings Using JavaScript There is also a way to visually view your binding from within your JavaScript code. These interfaces are documented here: nsIXFormsAccessors ## Mozilla Debugging Tips Here are some suggestions for people that are debugging XForms: Mozilla XForms Troubleshooting page ## Testing Submissions Sometimes when you are creating complex submissions to web services you need to make sure that what the XForms application is generating is exactly what the web service is expecting. Sometimes a web service vendor will provide a sample web forms client that correctly calls their service but the documentation on calling that service is somewhat lacking. One solution to this problem it to watch the HTTP packets leave the working application and compare them with the HTTP packets with your XForms. This can be done using an HTTP proxy tools such as Charles which also runs as a Firefox extension. The \"network\" tab of standard web development debuggers, like Firebug and Google Chrome Javascript Console can be used to watch incoming and outgoing network traffic to and from the browser, allowing you to verify that the content of submissions, their methods, and HTTP error codes are what would be expected. ## Using an HTTP Proxy With Firefox A Proxy is a tools that \"stands in\" for a web server. It puts itself in between your web browser and the server and tells you what the browser just sent to the web server. To do this you have to set your web browser to use the proxy (by telling it to forward everything to another IP address) and the proxy then forwards it to the service. When you are finished using the proxy, make sure you remember to disable the proxy by going to the Firefox Tools/Options/General/Connection Settings and click the Direction Connection to the Internet. If you do not your web browser will no longer function when Charles or Tamper Data shuts down. ## Debugging WebDAV and Subversion There are some XForms that are designed to use HTTP put, HTTP post and \[w:WebDAV:WebDAV\]. The WebDAV allows you to store not just the first version of a form but go back and see prior versions. Subversion FAQ 1 suggests you run the Wireshark packet sniffer and look at the data in the HTTP messages. ## Verifiying that a file is well-formed To verify that a data file is well formed, you can use the RUWF (Are you well-formed)? The XML Syntax Checker ## Setting Mime-type in Internet Explorer Version 6.0 Some versions of IE 6.0 do not have the correct mime-type set for IE6. TO fix this you must add an entry to the Microsoft Windows Registry: Open the Command Shell Enter the command \"regedit\" [HKEY_CLASSES_ROOT\MIME\Database\Content Type\application/xhtml+xml] "CLSID"="{25336920-03F9-11cf-8FD0-00AA00686F13}" "Encoding"=hex:08,00,00,00 "Extension"=".xhtml" ## Discussion
# Latin/How to study a language on the Internet and in your head How do you think about languages as you study them? Typically, you will consider every punctuation mark and letter, all the verbs and nouns, adverbs and adjectives, and study them in order to make connections. Ideally, you will have a teacher to point you in the right direction, and help you make those connections. But when you have no teacher, those connections are left for you to discover. They may be clear or hidden, but either way you will have to make them yourself. As you explore this Wikibook, it will require the skill of critical thinking. You can never go wrong studying a language if you remember that exposing yourself to a language, even if you stumble in practice, is itself learning it. Looking things up too much can sometimes impede progress. Stretch your memory, read slowly, and re-read. As you will soon discover, you are about to study a language that is rich and full of meaning, the ancestor of the Romance languages, such as Spanish, French, Portuguese, Italian, and Romanian, and an outsized influence on many other languages besides, including English. ## So do not assume that\... \...Latin is like any other language. Do not assume ancient Roman culture is entirely unlike other cultures, however. The Romans grappled with issues that are universally dealt with. We, the authors, endorse memorization, and after that, immersion. You must develop Latin muscles, and a willingness to write or type things out, or drill using software, or with a friend. Note the patterns after you have memorized the forms, not before. Allow yourself to be mesmerized by them. Similarly, seek out explanation only after you have memorized forms. Memorize forms, then make sentences, then use your knowledge to speak or to write the language. ## See also - How to learn a language
# Latin/Special consideration: How to use a Wikibook when progress may mean inaccuracy The current rule for dealing with inaccuracy in this book is: if you are skilled enough then simply delete or fix what you don\'t understand or you think is wrong (but then add a full description before committing your changes) else try to note your level of schooling and your country of origin writing (in the summary box) about what confused you . Also try to use the \"revert?\" keyword near the confusing text. In other words, do not tolerate inaccuracy!
# Latin/Chapter 1 Verse # Latin I prose +------------------------------------------------------------+ \| `<b>`{=html}Lesson Vocabulary`</b>`{=html} \| +============================================================+ \| \| +------------------------------------------------------------+ \| `<font face="Arial" size="4">`{=html}Latin`</font>`{=html} \| +------------------------------------------------------------+ \| \| +------------------------------------------------------------+ \| fulgeo, -ere \| +------------------------------------------------------------+ \| aperio, -ire \| +------------------------------------------------------------+ \| dormio, -ire \| +------------------------------------------------------------+ \| habeo, -ere \| +------------------------------------------------------------+ \| semper \| +------------------------------------------------------------+ \| tempto, -are \| +------------------------------------------------------------+ \| dico, -ere \| +------------------------------------------------------------+ \| femina \| +------------------------------------------------------------+ \| facio, -ere \| +------------------------------------------------------------+ \| ecce! \| +------------------------------------------------------------+ \| velle:\ \| \| volo\ \| \| vis\ \| \| vult\ \| \| volumus\ \| \| vultis\ \| \| volunt \| +------------------------------------------------------------+ \| turba \| +------------------------------------------------------------+ \| attonitus \| +------------------------------------------------------------+ \| tantus, -a, -um \| +------------------------------------------------------------+ \| susurro, -are \| +------------------------------------------------------------+ \| patefacio, -ere \| +------------------------------------------------------------+ \| rideo, -ere \| +------------------------------------------------------------+ The following is a nice easy short story for the Latin novice: ------------------------------------------------------------------------ ### Lucius ad forum it Sol fulget. Lucius oculos aperit. Videt uxorem suam, Octaviam. Octavia dormit. Ergo, Lucius ad forum it. Lucius multos amicos habet. Unus ex amicis Claudius est. Claudius semper in foro est. Claudius temptat dicere cum feminis, quod Claudius multas feminas amat. Multae feminae, tamen, Claudium non amant. Lucius ad forum ambulat. Multos Romanos videt. Unus Romanorum ad cives orationem facit. Est Claudius! \"Ecce! Ecce!\" dicit Lucius. Lucius vult dicere cum amico. Claudius, tamen, dicit ad turbam. \"Amicus meus, Lucius\" dicit, \"hominem necavit.\"^A^ Lucius anxius respondet, \"Quid dicis, amice?\" Claudius est attonitus. Dicit, \"Te non video, mi Luci\...\" Lucius respondet, \"hominem non necavi! Cur tanta dicis?\" Claudius susurrat, \"Volo videri^B^ fortissimus, amice. Feminae te amant. Me dolent^C^.\" Lucius omnia^D^ turbae^E^ patefacit. Multae feminae ad Claudium misserimum rident. Mox, etiam Claudius ad se ridet. ------------------------------------------------------------------------ - ^A^ Necavit is the perfect form of necare, meaning \"he killed.\" For more, check out the next chapter. ```{=html} <!-- --> ``` - ^B^ Videri means \"to appear,\" (or more literally, \"to be seen\") and is the passive infinitive of video. There is more on that in chapters 2-4. - ^C^ Me dolet means \"makes me suffer\". - ^D^ Omnia means \"everything\". - ^E^ turbae is the dative case of \"turba\", meaning \"to the crowd\".
# Latin/Lesson 4-Ablative ## The Ablative Case The ablative case in Latin has 9 main uses: 1. With certain prepositions, eg. in, cum, sub, ab 2. Instrumental ablative, expressing the equivalent of English \"by\", \"with\" or \"using\" 3. Ablative of manner, expressing `<b>`{=html}how`</b>`{=html} an action is done, only when an adjective is used alongside it. _Example_: `<i>`{=html}Magnā cūrā id scrīpsit: he wrote it with great care.`</i>`{=html} 4. Ablative of time `<b>`{=html}when`</b>`{=html} or `<b>`{=html}within which`</b>`{=html}. _note:_ not to be mistaken with the `<i>`{=html}accusative`</i>`{=html} of time which indicates `<b>`{=html}for how long a period of time`</b>`{=html} an action occurs. 5. Locative Ablative, using the ablative by itself to mean \"in\", locating an action in space or time 6. Ablative of separation or origin, expressing the equivalent of English \"from\" 7. Ablative of comparison; when the first element to be compared was in the nominative or accusative case, `<i>`{=html}quam`</i>`{=html} was often omitted and the second element followed in the ablative case. 8. Ablative with special deponents, which is technically the `<i>`{=html}instrumental ablative`</i>`{=html} but is used idiomatically with a few deponent verbs, such as ūtor, fruor, fungor, potior, vēscor 9. Ablative Absolute, which is a type of participial phrase generally consisting of a noun (or pronoun) and a modifying participle in the ablative case; usually set off by commas, the phrase describes some general circumstances under which the action of the sentence occurs. The different uses of the ablative will be dealt progressively. For a summary of all forms of the ablative, please consult the Appendix. ## Grammar Part 5: The Power of the Ablative Case Ablative generally indicates position in time and/or space (i.e. when and where). It can also indicate the idea of ways of getting to a location, abstractly or concretely. ### Ablative of Means #### Exercise How would you translate \"I made the toga by hand\"? - *Hint: You would not (and should not) use the genitive. The case you are studying right now can be used _by itself_ for this goal.* - *Hint: Remember that you won\'t need to use the pronoun \"I,\" since Latin is based not on word order, but on the endings!* - *Glossary:* : \"to make\" - Facio (\"I make\"), facere (\"to make\"), feci (\"I made\"), factus (\"made\") : \"toga\" - Toga, togae feminine : \"hand\" - Manus, manus feminine (This is fourth declension) ##### Answer Answer: Togam manu feci. In this case, the word \"manu\" is in the ablative (see fourth declension list) and thus means \"by hand.\" #### Exercise I have my wisdom by means of my teacher. - \'Glossary:\'\' : \"wisdom\" - Sapientia, sapientiae feminine : \"to have\" - Habeo (\"I have\"), habere (\"to have\"), habui (\"I had\"), habitus (\"had\") : \"teacher\" - Magister, magistri masculine (This is a second declension word, despite the \'r\' at the end, like puer.) ##### Answer Answer: Habeo sapientiam magistro. ### Ablative of Time How would you say: I will arrive at the 5th hour. \'at the 5th hour\' is indicating position of time. Thus, it can be put into the ablative case, giving: `<i>`{=html}adveniam quinta hora`</i>`{=html} In general, therefore, in order to say \"In the morning\", \"At nine O\'clock,\" or \"In the tenth year,\" use ablative. It is generally used to refer to a specific time in which something has, does, or will occur. Example: I will leave in the night. Hint: Future tense can be looked up in the appendices of this Wikibook! Hint: to leave- discedo, discedere; night- nox, noctis(This is a third declension word!) ##### Answer Answer: Discedam nocte. Note the simplicity in which Latin translates the six words into simply two. The ending based language completely negates the need for the words \"I,\" \"will,\" \"in,\" and \"the.\" ### Ablative of Place Naves navigabant mari. The ships were sailing on the sea. The ablative is also useful for showing the location of things, in general where you would use the words on, in, or at. There is an exception for the slightly more archaic locative, which is used with the words domi (from domus, domus, f., home), ruri (from rus, ruris, n., country \[as opposed to city\]), and Romae (from Roma, Romae, f., Rome), as well as with the names of towns, cities and small islands. Latin has its own way of handling prepositions depending on the nouns and their cases in the sentence, including the versatile in, which can take many different meanings depending upon the case of the object. ## Ablative with prepositions Here are a few prepositions that can take the ablative (for a fuller list, see the lesson on adverbs and prepositions in the previous chapter): -------------------------------- ---------------------------------- `<B>`{=html}Latin`</B>`{=html} `<B>`{=html}English`</B>`{=html} in[^1] in, on a/ab from de down from, concerning e/ex out of, out from cum with sine without pro on behalf of, in front of super[^2] upon, above, beyond sub[^3] under, beneath -------------------------------- ---------------------------------- ```{=html} <references/> ``` As a general rule, when motion is implied, use the accusative instead. ### Example 3 Servus ex agris venit. : \"The slave came from the fields.\" Note: Ager (ager, agri, m., field) must take an ablative suffix to match the preceding preposition, in this case e/ex. Incidentally, both ager and campus mean \"field,\" but ager, like its English derivative \"agriculture\", connotes a farming field, while campus (think \"camping\" or \"college campus\") means \"open field.\" The Campus Martius was a large field in Rome used for military training. ## The Vocative Case While you will rarely need to ask Lupus where the bathroom is in Latin, you may find yourself reading either quotes or letters in which a person is being directly addressed. The case it will be in is the vocative. For example, \"Hail, Augustus\" will appear in Latin as Ave Auguste, and not Ave Augustus. Each declension has its own form of the vocative singular and plural. They are listed in the table below. Furthermore, in all but the second declension, the nominative and vocative are exactly the same! ------------ ------- ------------------------ ------- -------- ------- Number First Second\* Third Fourth Fifth Singular a us-\>e, ius-\>i, r-\>r \-- us es Plural\\ ae i es us es ------------ ------- ------------------------ ------- -------- ------- - In the second declension singular, there are three separate possibilities for the vocative, depending on its nominative ending. Hence, if it is a us word, it will become an e and so forth. #### Examples for different declensions in the second declension - -us: : Lupus -\>Lupe (given name, wolf) - -ius: : Filius -\> Fili (son) : Horatius-\> Horati (given name) - -r: : Puer-\> Puer (boy) : In all cases, the plural vocative is exactly the same as the plural nominative. This extends to those words which are neuter, which always have an \'a\' for the nominative and vocative. #### Examples 1. Hello, Sextus.(Hello= Salve)\* : Salve, Sexte. 2. Speak, girl! (Speak= dico, dicere, dixi)\* : Dic, puella. 3. Knee, run!\(Knee= genu; run= curro, currere, cucurri)\ : Genu, curre! 4. Oh, heart, why do you lead me? (Oh-o; heart- cor, cordis-f.; lead-duco, ducere; : O, cor! Cur ducis tu me? - Note that the first three also require use of the imperative. The imperative is used when ordering or telling someone what to do, e.g.- \"Stop,\" or \"Get away from me.\" The basic form of the imperative is created by dropping the \"re\" off of the infinitive form of the verb, as in: Amare, which becomes Ama; at least in the singular active form, which is all that these exercises require. More can be found about this subject in the chapter on verbs. [^1]: Means \"into\" or \"against\" when used with the accusative [^2]: Has static meaning when used with the ablative but connotes motion when used with the accusative [^3]: Usually means \"up to\" or \"up to the foot of\" when used with the accusative
# Latin/Lesson 5-Declensions ## 3rd, 4th, and 5th Declension Nouns We have already seen the first two declensions: ------------ ---------------------- ---------------------- 1^st^ declension 2^nd^ declension -a -us -um (neuter) SINGULAR PLURAL SINGULAR nominative puell-a puell-ae accusative puell-am puell-ās genitive puell-ae puell-ārum dative puell-ae puell-īs ablative puell-ā puell-īs ------------ ---------------------- ---------------------- ------------------------------------------------------------------------ We will now complete the table of nouns with the 3rd, 4th, and 5th declensions. These declensions are more difficult to work with because their nominative and accusative plural forms are identical, as are their dative and ablative plural forms. To distinguish the cases, you must use a very simple key: context. Context will tell you the meaning. ### 3rd Declension Nouns 3rd declension nouns have two stems : The nominative and vocative singular stem and the stem used for all other cases. Both stems have to be memorized for each noun. Feminine and masculine forms are indistinguishable. #### 3rd Declension Masculine or Feminine, no i-stem: (each word has a set gender): rēx, m. 3rd Declension Singular Plural ---------------- ---------- ------------ nominative rēx rēg-ēs accusative rēg-em rēg-ēs genitive rēg-is rēg-um dative rēg-ī rēg-ibus ablative rēg-e rēg-ibus #### 3rd Declension Neuter, no i-stem: litus 3rd Declension Neuter Singular Plural --------------------------------------- ------------ -------------- `<I>`{=html}nominative\`</I>`{=html} litus* litor-a accusative litus litor-a genitive litor-is litor-um dative litor-ī litor-ibus ablative litor-ī litor-ibus #### 3rd Declension Masculine or Feminine, 2-consonant base i-stem: (each word has a set gender): ars, artis, f. i-stem nouns differ from other 3rd declension nouns in that some of the forms have endings changed to include is. There are two main kinds of masculine/feminine i-stem nouns. The first kind has its usual stem end in two consonants; the example here, for instance, has its base art- end in -rt-. The last consonant of the nominative singular form always ends in either -s or -x. 3rd Declension Singular Plural ---------------- ---------- ------------ nominative ars art-ēs accusative art-em art-ēs genitive art-is art-ium dative art-ī art-ibus ablative art-e art-ibus #### 3rd Declension Masculine or Feminine, parisyllabic i-stem: (each word has a set gender): nūbēs, f. The other kind of masculine/feminine i-stem noun has the property that its nominative and genitive singular forms have the same number of syllables. They are therefore called parisyllabic. All nouns of this form have their nominative singular form end in either -ēs or -is. 3rd Declension Singular Plural ---------------- ---------- ------------ nominative nūbēs nūb-ēs genetive nūb-is nūb-ium dative nūb-es nūb-es accusative nūb-ī nūb-ibus ablative nūb-e nūb-ibus #### 3rd Declension Neuter i-stem: mare Neuter i-stem nouns have their nominative singular forms end with -al, -ar, or -e. 3rd Declension Neuter Singular Plural --------------------------------------- ---------- ------------ `<I>`{=html}nominative\`</I>`{=html} mare* mar-ia accusative mare mar-ia genitive mar-is mar-ium dative mar-ī mar-ibus ablative mar-ī mar-ibus #### List of common 3rd declension stem change patterns Singular Nominative Main stem Main gender Examples --------------------- ----------- ------------- ------------------------ -is -is masc/fem canis, navis, hostis -s -is masc/fem urbs, rex\, matrix\ -s -tis masc/fem nox\, mons, pons -o -onis masc/fem legio, auditio, statio -en -inis neuter carmen, flumen, examen -or -oris masc/fem amor, timor -us -oris neuter litus, corpus -us -eris neuter genus, vulnus - regs and matrics, respectively, but the gs and cs both compound into x. The c and g stay in the other cases, hence regis and matricis as their genitives. Nox (gen. noctis) works similarly. ### 4th Declension Nouns #### 4th Declension Masculine/Feminine (each word has a set gender) gradus, m. `<B>`{=html}4th Declension`</B>`{=html} Singular Plural ----------------------------------------- ----------- ------------- nominative grad-us* grad-ūs accusative grad-um grad-ūs genitive grad-ūs grad-uum dative grad-uī grad-ibus ablative grad-ū grad-ibus #### 4th Declension Neuter: cornū 4th Declension Neuter Singular Plural ----------------------- ----------- ------------- nominative corn-ū corn-ua vocative corn-ū corn-ua accusative corn-ū corn-ua genitive corn-ūs corn-uum dative corn-ū corn-ibus ablative corn-ū corn-ibus ### 5th Declension Nouns The 5th declension has no neuter nouns. The masculine and feminine forms are again indistinguishable. #### 5th Declension Masculine/Feminine (each word has a set gender; most are feminine): rēs, f. 5th Declension Feminine/Masculine Singular Plural ----------------------------------- ---------- ---------- nominative r-ēs r-ēs vocative r-ēs r-ēs accusative r-ēm r-ēs genitive r-ēī r-ērum dative r-ēī r-ēbus ablative r-ē r-ēbus ## Exercises ### Exercise 1 ------------------------------------------------------------ `<font face="Arial" size="2">`{=html}Latin`</font>`{=html} villa, -ae mittō, -ere, mīsī, missum nomen, nominis maledicō, -dicere, -dīxī, -dictum placeō, -ere, placui, placitum + dat quā rē iste, ista, istud interficiō, -ficere, -fēci, -fectum volō, velle, voluī mandō, mandere, mansī, mansum ------------------------------------------------------------ ### Exercise 2
# Latin/Lesson 6-Irregular Verbs ## Irregular Verbs Irregular verbs do not fit in any particular conjugation. Irregular verbs conjugate but not in a predictable manner. An example of an irregular verb that you have met is \'esse\'. There are a few others which will be listed in the present indicate active tense below for you to memorise and refer to. <table> <tbody> <tr class="odd"> <td><p>Verb</p></td> <td><p>Meaning</p></td> <td><p>ego</p></td> <td><p>tu</p></td> <td><p>is/ea</p></td> <td><p>nos</p></td> <td><p>vos</p></td> <td><p>ei/eae</p></td> <td><p>Imperative sing.</p></td> <td><p>Imp. pl</p></td> </tr> <tr class="even"> <td><p>ire</p></td> <td><p>to go</p></td> <td><p>eo</p></td> <td><p>is</p></td> <td><p>it</p></td> <td><p>imus</p></td> <td><p>itis</p></td> <td><p>eunt</p></td> <td><p>i</p></td> <td><p>ite</p></td> </tr> <tr class="odd"> <td><p>esse</p></td> <td><p>to be</p></td> <td><p>sum</p></td> <td><p>es</p></td> <td><p>est</p></td> <td><p>sumus</p></td> <td><p>estis</p></td> <td><p>sunt</p></td> <td><p>es</p></td> <td><p>este</p></td> </tr> <tr class="even"> <td><p>fieri</p></td> <td><p>to become</p></td> <td><p>fio</p></td> <td><p>fis</p></td> <td><p>fit</p></td> <td><p>fimus</p></td> <td><p>fitis</p></td> <td><p>fiunt</p></td> <td><p>fi</p></td> <td><p>fite</p></td> </tr> <tr class="odd"> <td><p>velle</p></td> <td><p>to wish</p></td> <td><p>volo</p></td> <td><p>vis</p></td> <td><p>vult</p></td> <td><p>volumus</p></td> <td><p>vultis</p></td> <td><p>volunt</p></td> <td><p>(none)</p></td> <td><p>(none)</p></td> </tr> <tr class="even"> <td><p>malle</p></td> <td><p>to prefer</p></td> <td><p>malo</p></td> <td><p>mavis</p></td> <td><p>mavult</p></td> <td><p>malumus</p></td> <td><p>mavultis</p></td> <td><p>malunt</p></td> <td><p>(none)</p></td> <td><p>(none)</p></td> </tr> <tr class="odd"> <td><p>nolle</p></td> <td><p>to be unwilling</p></td> <td><p>nolo</p></td> <td><p>non vis</p></td> <td><p>non vult</p></td> <td><p>nolumus</p></td> <td><p>non vultis</p></td> <td><p>nolunt</p></td> <td><p>noli</p></td> <td><p>nolite</p></td> </tr> <tr class="even"> <td><p>ferre</p></td> <td><p>to carry</p></td> <td><p>fero</p></td> <td><p>fers</p></td> <td><p>fert</p></td> <td><p>ferimus</p></td> <td><p>fertis</p></td> <td><p>ferunt</p></td> <td><p>fer</p></td> <td><p>ferte</p></td> </tr> <tr class="odd"> <td><p><I>The imperatives noli and nolite are used to mean "don't", eg. "nolite ire" = "don't go!"</I><br /> <I>Sometimes ferre is considered to be an 'o' stem 3rd conjugation verb. For practical purposes ferre is irregular.</I></p></td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> <td></td> </tr> </tbody> </table> ## Exercise 1 ## Exercise 2 1\. Decline the following five nouns in both singular and plural number in the five common cases (nominative, accusative, genitive, dative, ablative): ----------------------------------- `<B>`{=html}Singular`</B>`{=html} Nominative Accusative Genitive Dative Ablative `<B>`{=html}Plural`</B>`{=html} Nominative Accusative Genitive Dative Ablative ----------------------------------- 2\. Conjugate the verb \'servāre\' in both singular and plural number and all three persons. 3\. Conjugate the verb \'esse\', in both singular and plural number and all three persons. 4\. Translate: Nota Bene: Often Latin uses the present to indicate a \'vivid past\'. It would be suitable to translate the following passage in the past tense. ---------------------------------------------------------------------------------- `<span style="font-family:Arial; font-size:small;">`{=html}Latin`</span>`{=html} heri taberna, -ae solea, -ae sic solus, -a, -um casa, -ae sto, stare, steti, statum ---------------------------------------------------------------------------------- Heri, ad tabernam eō. In tabernā sunt trēs rēs quārum amō duas sōleās et unam mensam. Habeō trēs denariōs, sīc ego emeō mensam sōlum quod sum nōn dīvīnitās. Hodiē, mensa est in casā meā. In triclīnio stat.
# Latin/Lesson 8-Imperfect and Future # Imperfect and Future constructs Warning: Beyond the imperfect, this page is not entirely clear. Do not use it beyond the basic imperfect if you are a first time Latin student. See discussion for my thoughts on this. ## Imperfect Active Indicative The imperfect is a construct like: : I was seeing. In Latin it would look like this: : Vidēbam. English has a similar construct called progressive past. Actions seem incomplete, and so the imperfect label. For example, \"I was running,\" \"We were sailing,\" \"They were calling.\" Note that \'to be\' is always there. Latin, however, would sometimes use imperfect like simple past; accordingly, \"We were sailing\" could be translated as \"We sailed.\" Other translations of imperfect can be used to/kept such as \"We used to sail/We kept sailing.\" Regardless of language, the concept of an imperfect is important. Imperfect is called imperfect for a reason - in Latin, the verb \"perficere\" means to finish/complete, which is what perfect is from. Thus, imperfect, in the grammatical sense, means not finished - that the action could be or could not be completed. Perfect instead means it has been finished - I saw. You have already seen, and it is now completed. I was seeing implies that the action is not yet completed. The perfect tense, which we will learn later, is a more immediate reference to the past. The name, imperfect, helps you remember its use: in situations where you can\'t say when an event started or ended or happened, you must use the imperfect. In situations where you can know when an event started or ended or happened, use the perfect. You conjugate the imperfect tense this way: verb + -bā- + personal ending The endings for imperfect are: Sg. 1. -bam 2. -bās 3. -bat Pl. 1. -bāmus 2. -bātis 3. -bant Note that the only thing we add are ba + the personal endings (the same as in the present tense) to the infinitive stem. This gives us the imperfect conjugation. Note that in third and fourth conjugations, you will have to form it differently. There is \no\ rule to explain this, it just is, although there are memorization techniques that can help. ven`<U>`{=html}i`</U>`{=html}re is 4th conjugation and is formed like: : veniēbam : veniēbās : veniēbat : veniēbāmus : veniēbātis : veniēbant For third conjugation -iō stem verbs, the imperfect is like so: capere (to capture or seize) : capiēbam : capiēbās : capiēbat : capiēbāmus : capiēbātis : capiēbant Note that it is easiest to think of what the endings -ere and `<U>`{=html}i`</U>`{=html}re lack. The imperfect -bā- + the personal ending, which we can call the imperfect conjugation, must be prefixed by -iē-. A few examples: : amābam - I was loving (A-conjugation\--1st) : monēbātis - You were warning \[object/personage\] (of something negative) (Pl.) (2nd Conjugation) : vincēbāmus - \'We were defeating (3rd conjugation) : capiēbant - They were catching (short I-conjugation\--3rd conjugation) : pellēbat - She/he/it was propelling (drive something (not a vehicle), propel something) (consonantic conjugation) (Wiki-reading tips: See discussion. Some of the above may be unclear, however the clarifying \'\--\' and \'/\' indicate verification. We may not know what the original author intended, but we know what conjugations the examples are.) ## Future I, Active Future active is a tense which, unsurprisingly, refers to something which has not yet happened. The endings are fairly basic, and follow fairly regular rules - however, the future endings used in 1st and 2nd conjugation differ from the endings of 3rd, 3rd-iō, and 4th. For example - \"amō, amāre\" (1st conjugation) would be : Amābō - I will love : Amābis - You will love : Amābit - He/She/It will love : Amaābimus - We will love : Amābitis - Y\'all will love : Amābunt - They will love NOTE: 1st person singular and 3rd person plural use -bō and -bunt, not -bi-. NOTE: the B and the BIs - the distinguishing feature of future tense in Latin. With \"veniō, venīre\" (4th conjugation), however, the endings are different. In future, this is what they look like: : Veniam - I will come : Veniēs - You will come : Veniet - He/She/It will come : Veniēmus - We will come : Veniētis - Y\'all will come : Venient - They will come \[deleted paragraphs go here. deleted to maintain rigorous accuracy, which we will go back to striving for.) To clarify: ven`<U>`{=html}ī`</U>`{=html}re, veniō.. we know it is 4th conjugation verb and if we look at its first person singular conjugation, we see that it is an -iō verb, because the conjugation of the first person singular is \"venio\". (an io category exists within 3rd and fourth conjugations and is a more general concept which we will briefly introduce here by using venire, venio as an example). Let\'s first identify what we know. We know it is 4th conjugation -io because it ends in `<U>`{=html}ī`</U>`{=html}re, which tells us that it is 4th conjugation, and io because its first person singular ends in io (venio). Because it is -iō, we leave the -i- in. So, when we are asked (as all textbooks should phrase these `<B>`{=html}new`</B>`{=html} questions): What are the steps to form the future 2nd person conjugation? We say: 1. It is better to know more than you need: check the infinitive nominative singular, we now know that it is 4th conjugation io. 2. We now know that we can form the stem: the stem is veni and can then add a personal ending\--leaving in the i. We leave in the i because it is io. Because it looks weird, we never leave the i in the future perfect. What is the form for venīre, in the future tense, in the 2nd person? The answer is veniēs. ## Future conjugation Example: I will love: : *amābō* The table at the end of this page tries to summarize the future tense, with both sets of personal endings. As the warning notes, this summary may confu panda As an aid to your understanding, this table only applies to the future tense. Do not assume the table is displaying a pattern that is somehow applicable to all of Latin. (Wiki-reading-tip: This is why they are in the future section, and were not discussed before.) The A- and the E- conjugation are (relatively) straight-forward. The others are more advanced, and as the warning notes, could confuse a first-time student. Commercial textbooks probably explain it better at this point, although laying their explanation in a table like the one below is well-advised. Leave items marked with a ? in until issues are resolved. Take a look at the following table: ----------------- ------------------ ---------------------------------- --------------- ----------------- A E \'\'\'long I (vincere/3rd conj.) short I Consonantic amā-bo monē-bo vinc-am capi-am pell-am ama-bis mone-bis vinc-es capi-es pell-es ama-bit mone-bit vinc-et capi-et pell-et ama-bimus mone-bimus vinc-emus capi-emus pell-emus ama-bitis mone-bitis vinc-etis capi-etis pell-etis ama-bunt mone-bunt vinc-ent capi-ent pell-ent ----------------- ------------------ ---------------------------------- --------------- ----------------- The vocabulary mostly consists of verbs, and can easily be looked up in a dictionary. We will give a limited translation below, and the rest, for those who are particularly adept at language learning, can be learned through immersion. : capere (3rd conjugation\--short ere): to seize, metaphorically or literally \[see dictionary for full explanation\] : amare (first conjugation -are): to love ## Exercises
# Latin/Chapter 2 Verse ## Using a Dictionary Foremost, Latin verbs are listed using the present indicative first person singular active construct of the verb. For example, to find the meaning of the verb amāre, you must find amō listed in the dictionary. Some verbs like esse and ferre are highly irregular and use different stems to form the perfect tenses. Nouns are usually much easier. They are always given in the nominative singular. If you see a noun such as vōcem and do not know what it is, do not fret. If you look for voc- in the dictionary, you will not find what you are looking for. The ending -em typically belongs to the third-declension accusative; thus, be aware that third-declension nouns have radically changing stems. Those that have the consonant c or g usually have the consonant x in the nominative singular. Thus the nominative singular of vōcem is vōx, and rēx becomes rēgem in the accusative singular. There are plenty of other simple rules which you will learn through experience. Words that do not conjugate or decline (like prepositions and particles) are listed under their only form. ## Exercise 1 ### Vocabulary 1. affectus, -ūs, m., goodwill 2. confessiō, -ōnis, f., confession 3. dē, from, about, concerning 4. liber, librī, m., book 5. malus -a -um, evil, bad 6. placeō -ēre + dative, to please (placuīsse is a perfect infinitive) 7. filia, -ae f., daughter 8. puella, -ae f., girl ### Other Difficulties 1. quod ad mē attinet, as far as I\'m concerned 2. cum scriberentur, when they were written (imperfect passive subjuntive) 3. quid sentiant, what they think (present subjunctive in indirect question) 4. ipsī viderint, (loosely) they will see in their own way (future perfect) 5. eōs placēre sciō, accusative-infinitive construction for indirect statement: \"I know they \[the books\] please\" ### Passage
# Latin/Lesson 2-Active v Passive A verb\'s voice shows the relationship between the subject and the action expressed by the verb. Latin has two voices: active and passive. In the active voice, the subject of the clause performs the verb on something else (the object), e.g., \"The girl sees the boy.\" In the passive voice, the subject of the sentence receives the action of the verb, e.g., \"The boy is seen by the girl.\" The personal endings in the active voice are: -ō/-m, -s, -t, -mus, -tis, -nt. The personal endings in the passive voice (present, imperfect, future) are: -r, -ris, -tur, -mur, -mini, -ntur. Singular Plural ----- ---------- -------- 1st -ō/-m -mus 2nd -s -tis 3rd -t -nt : Personal Active Singular Plural ----- ---------- -------- 1st -r -mur 2nd -ris -mini 3rd -tur -ntur : Personal Passive In the perfect, pluperfect and future perfect, the passive voice is formed by the fourth principal part plus the proper forms of sum, esse. For the perfect tense, use the present forms of esse, for the pluperfect use the imperfect forms of esse, and for the future perfect use the future forms of esse. The fourth principal part, when used in a passive construction, acts as a first-second declension adjective and is declined accordingly. As stated before, when the passive voice is used, the subject receives the action of the verb from another agent. This agent, when it is a person, is expressed by the preposition ā/ab plus the ablative case. This construction is called the ablative of personal agent. The ablative of cause is used without a preposition when the agent is not a person. ## Examples: - Active: Puella puerum videt. (The girl sees the boy.) :\Passive: Puer ā puellā vidētur.* (The boy is seen by the girl.) : Puella takes ā and the ablative, as it is a personal agent. - Active: Timor virum capit. (Fear seizes the man.) :\Passive: Vir timore capitur.* (The man is seized by fear.) : Timore is ablative of cause. - Active: Hostēs urbem oppugnābant. (The enemies were attacking the city.) :\Passive: Urbs ab hostibus oppūgnābātur.* (The city was being attacked by the enemies.) ## Deponent verbs Some verbs are always passive in form, even though they have an active meaning. For example: - filius agricolam `<b>`{=html}sequitur`</b>`{=html} - The son follows the farmer - sol `<b>`{=html}ortus est`</b>`{=html} - The sun has risen - agricolae hostes `<b>`{=html}verentur`</b>`{=html} - The farmers fear the enemies - gladio `<b>`{=html}usus sum`</b>`{=html} - I used a sword Some, called semi-deponent verbs, take on a passive form on only in the perfect. For example: - colono `<b>`{=html}confido`</b>`{=html} - I trust the farmer - colono `<b>`{=html}confisus sum`</b>`{=html} - I trusted the farmer Note that some deponent and semi-deponent verbs take the accusative case (eg. vereor, vereri, veritus sum = I fear), some the ablative (eg. utor, uti, usus sum = I use) and some the dative (eg. confido, confidere, confisus sum = I trust). When you first encounter such a verb in Latin, be sure to remember the case of the object the verb is taking along with its spelling and meaning.
# Latin/Lesson 7-Future and Past Perfect ## Future perfect The future perfect tense is used for an action that will have been completed in the future by the time something else has happened. English example: \"I will have seen the movie by the time it comes out.\" To form the future perfect, take the perfect stem and add the future perfect endings: ```{=html} <table border="1" cellpadding="5"> ``` ```{=html} <tr> ``` ```{=html} <td> ``` -erō ```{=html} </td> ``` ```{=html} <td> ``` -erimus ```{=html} </td> ``` ```{=html} </tr> ``` ```{=html} <tr> ``` ```{=html} <td> ``` -eris ```{=html} </td> ``` ```{=html} <td> ``` -eritis ```{=html} </td> ``` ```{=html} </tr> ``` ```{=html} <tr> ``` ```{=html} <td> ``` -erit ```{=html} </td> ``` ```{=html} <td> ``` -erint ```{=html} </td> ``` ```{=html} </tr> ``` ```{=html} </table> ``` Note the similarities to the future tense of sum, except for the third person plural ending -erint[^1] in place of -erunt, which serves as the perfect ending instead. Hence: amāverō, I will have loved; vīderitis, you (pl.) will have seen ```{=html} <references/> ``` ## Pluperfect The pluperfect tense is used to describe something in the past that happened before another event in the past. English example: \"I had graduated by the time I applied for a job.\" To form the pluperfect, take the perfect stem and add the pluperfect endings: ```{=html} <table border="1" cellpadding="5"> ``` ```{=html} <tr> ``` ```{=html} <td> ``` -eram ```{=html} </td> ``` ```{=html} <td> ``` -erāmus ```{=html} </td> ``` ```{=html} </tr> ``` ```{=html} <tr> ``` ```{=html} <td> ``` -erās ```{=html} </td> ``` ```{=html} <td> ``` -erātis ```{=html} </td> ``` ```{=html} </tr> ``` ```{=html} <tr> ``` ```{=html} <td> ``` -erat ```{=html} </td> ``` ```{=html} <td> ``` -erant ```{=html} </td> ``` ```{=html} </tr> ``` ```{=html} </table> ``` Hence: amāveram, I had loved; vīderātis, you (pl.) had seen ## Examples De Acutiliano autem negotio quod mihi mandaras* (mandaveras), ut primum a tuo digressu Romam veni, confeceram.* (Cicero, Ad Atticum 1.5) : \"But as to the business of Acutilius that you had entrusted with me, I had already taken care of it when I came to Rome first thing after your departure.\" Note the relationship of the pluperfect verbs mandaras (-aras is a common contraction for -averas) and confeceram to the perfect verb veni. Ego certe meum officium praestitero. (Caesar, De Bello Gallico IV) : \"I certainly will have prevailed in my duty.\" [^1]: -int as an ending is rare; -erint and sint are two of the most common
# Latin/Lesson 8-Ablative Absolute and Accusative Infinitive ## Ablative Absolute The ablative absolute construction is used in a sentence to provide a background for the main action in the sentence. An ablative absolute is formed with a noun and an adjective or participle in the ablative case. `<i>`{=html}`<b>`{=html}convivis ingressis`</b>`{=html} ille cenam parat`</i>`{=html} `<b>`{=html}With the guests having entered`</b>`{=html}, he prepares dinner. `<i>`{=html}`<b>`{=html}domino convivanti`</b>`{=html} servi diligenter laborabant`</i>`{=html} `<b>`{=html}With the master feasting`</b>`{=html}, the slaves were working diligently. `<i>`{=html}`<b>`{=html}omnibus ieiunis`</b>`{=html} multos panes parare debuit`</i>`{=html} `<b>`{=html}With everyone (being) hungry`</b>`{=html}, he had to prepare lots of bread. ## Accusative Infinitive The accusative infinitive construction is used to indirectly report speech or thoughts. An accusative infinitive construction is formed by taking the indirect clause and putting the subject in the accusative and the verb in the infinitive. `<i>`{=html}ille credit `<b>`{=html}pueros stultos esse`</b>`{=html}`</i>`{=html} He believes the boys to be fools = He believes `<b>`{=html}that the boys are fools`</b>`{=html}. `<i>`{=html}magister parentibus dicit `<b>`{=html}pueros stultos esse`</b>`{=html}`</i>`{=html} The teacher says to the parents `<b>`{=html}that the boys are fools`</b>`{=html}. `<i>`{=html}colonus uxori dicit `<b>`{=html}se confectum esse`</b>`{=html}`</i>`{=html} The farmer says to his wife `<b>`{=html}that he is exhausted`</b>`{=html}. In this sentence, note how the reflexive `<i>`{=html}se`</i>`{=html} refers to the main subject of the sentence. `<i>`{=html}colonus uxori `<b>`{=html}dixit`</b>`{=html} se confectum esse`</i>`{=html} The farmer said to his wife that he `<b>`{=html}was`</b>`{=html} tired. Note how esse, despite being a present infinitive, is translated into the past tense. This is because the infinitive uses the action of the main verb, in this case `<i>`{=html}dixit`</i>`{=html} as a reference point instead of the present. But what about sentences such as \"the farmer `<b>`{=html}says`</b>`{=html} to his wife that he `<b>`{=html}worked`</b>`{=html} diligently\"? For those, you need to use the `<b>`{=html}past infinitive`</b>`{=html}. ### Overview of infinitives in all tenses Tense Active Passive Active Passive Active Passive Active Passive --------- ------------------------ ---------------------- ------------------------- ----------------------- ------------------------ ---------------------- ------------------------- ----------------------- Present amare amari monere moneri regere regi audire audiri Past amavisse amatus, -a, -um esse monuisse monitus, -a, -um esse rexisse rectus, -a, -um esse audivisse auditus, -a, -um esse Future amaturus, -a, -um esse amatum iri moniturus, -a, -um esse monitum iri recturus, -a, -um esse rectum iri auditurus, -a, -um esse auditum iri The sentence \"The farmer says to his wife that he worked diligently\" would thus translate as: `<i>`{=html}colonus uxori dicit se diligenter laboravisse`</i>`{=html} The following examples show how different infinitives with the main verb in the past and present would appear in English: - colonus uxori dixit se diligenter laboravisse = The farmer said to his wife that he `<b>`{=html}had worked`</b>`{=html} diligently. - colonus uxori dixit se diligenter laborare = The farmer said to his wife that he `<b>`{=html}was working`</b>`{=html} diligently. - colonus uxori dixit se diligenter laboraturum esse = The farmer said to his wife that he `<b>`{=html}would work`</b>`{=html} (or `<i>`{=html}was going to work`</i>`{=html}) diligently. - colonus uxori dicit se diligenter laboraturum esse = The farmer said to his wife that he `<b>`{=html}will work`</b>`{=html} (or `<i>`{=html}is going to work`</i>`{=html}) diligently. - nuntius mihi dixit urbem deletam esse = The messenger told me that the city `<b>`{=html}had been destroyed`</b>`{=html} - nuntius mihi dixit urbem deleri = The messenger told me that the city `<b>`{=html}was being destroyed`</b>`{=html} - nuntius mihi dixit urbem deletum iri = The messenger told me that the city `<b>`{=html}would be destroyed`</b>`{=html} (or `<i>`{=html}was going to be destroyed`</i>`{=html}) - nuntius mihi dicit urbem deletum iri = The messenger told me that the city `<b>`{=html}will be destroyed`</b>`{=html} (or `<i>`{=html}is going to be destroyed`</i>`{=html}) ### Translation Exercises
# Latin/Chapter 3 Verse The following poem is written in Hendecasyllabic. It is an introductory, dedication poem written by the poet Gaius Valerius Catullus. It is commonly referred to as \"Catullus 1\" or by its first line. : Cui dono lepidum novum libellum : arida modo pumice expolitum? : Corneli, tibi: namque tu solebas : meas esse aliquid putare nugas. : Iam tum, cum ausus es unus Italorum : omne aevum tribus explicare cartis\... : Doctis, Iuppiter, et laboriosis! : Quare habe tibi quidquid hoc libelli--- : qualecumque, quod, o patrona virgo, : plus uno maneat perenne saeclo!
# Latin/Lesson 1-Subjunctive ## Subjunctives The Subjunctive is one of the three different moods a Latin verb can take. The two other moods are the Indicative and the Imperative. The subjunctive is perhaps the most common and also most difficult to grasp, and there are a great number of different subjunctive uses. The subjunctive mainly expresses doubt or potential and what could have been. Whereas the indicative declares \"this happened\" or \"that happened,\" the imperative is called \'jussive,\' which is from \'iubere\' - to command, bid. Examples - \"Let me go\" and \"May I go?\" are statements of potential; the speaker is not entirely certain his/her command will be followed. - \"Were I a king, I would have a golden throne.\" -this expresses what could be true, but is not. Speaker is not a king, and so will not get the throne. - \"May the force be with you!\" expresses the hope/potential that the force (Star Wars) will be with you. The essential word here is \'may\' - \"May the force be with you.\" \"If this were to happen,\" or \"May this happen!\" or \"I ask you to make this happen\" are all possible uses of the subjunctive. There are four subjunctives: present, imperfect, perfect, and pluperfect. There are no subjunctives in the future tense, which already incorporates an element of doubt. ### The Present Subjunctive The present subjunctive is similar to the present indicative, except marked by a change of the theme vowel. present stem + theme vowel change + ending #### Form In the present subjunctive, the theme vowel for every conjugation changes; in effect, the first conjugation masquerades as the second conjugation and all the other conjugations take on the appearance of the first. ----------------- ----- --------- ------ 1st Conjugation a becomes e 2nd Conjugation e becomes ea 3rd Conjugation e becomes a 3rd -io and 4th i becomes ia ----------------- ----- --------- ------ Some ways to remember this are in the following collapsed table. +------------------------------------------------+ \| Show \| +================================================+ \| She wears a giant diamond \| \| \| \| We beat a liar. \| \| \| \| We beat all liars. \| \| \| \| We eat a friar \| \| \| \| We eat a Fiat \| \| \| \| Never Fear a Liar \| \| \| \| Let\'s eat a diaper. \| \| \| \| Let\'s eat caviar. \| \| \| \| She wears a diamond. \| \| \| \| We eat caviar \| \| \| \| We fear a liar \| \| \| \| She wears a tiara \| \| \| \| We beat a giant. \| \| \| \| She reads a diary. \| \| \| \| She wears a diamond tiara. \| \| \| \| Let\'s beat that giant. \| \| \| \| Few Fear Fat Friars. \| \| \| \| Her breasts are giant. \| \| \| \| Clem Steams Clams in Siam \| +------------------------------------------------+ ### Example Conjugation porto, portare, portavi, portatus (1st conjugation - to carry) #### Present Indicative This is the present active indicative form of portāre, which has already been covered. Remember the join vowels. #### Present Subjunctive The present active subjunctive of portare would be conjugated as follows: Notice: - The -ā- vowel stem has changed to an -ē-. - The personal endings -m, -s, -t, -mus, -tis, -nt are used, as is done for regular indicative verbs. #### Present Subjunctive of Esse The present active subjunctive of sum, esse, the verb \"to be\", is conjugated as follows: Unlike the conjugation of the present active indicative form, the present subjunctive is regular. The same personal endings are affixed to si-. ##### Present Subjunctive of Posse Translates as \"May I/you/he/we/you/they be able\" ### Imperfect Subjunctive The imperfect subjunctive is formed by adding the personal endings -m, -s, -t, -mus, -tis, -nt or the passive endings -r, -ris, -tur, -mur, -mini, -ntur to the present infinitive active (often the second principal part). In other words, for vocō, vocāre, vocāvī, vocātum The imperfect subjunctives are formed thus: For deponent verbs, whose second principal part is the passive infinitive (e.g., cōnārī, verērī, patī, expedīrī) a pseudo present infinitive is used (e.g, cōnāre, verēre, patere, expedīre; although these forms do not exist as stand-alone infinitives, they actually ARE the singular imperatives for these deponent verbs) The imperfect subjunctive of the verb to be (sum, esse) is conjugated regularly, as are ALL irregular verbs, e.g.: possem, vellem, nollem, ferrem, irem) ## Uses of the Subjunctive Verbs in the subjunctive mood may assume special meaning in specific constructions. ### Volitive or Optative Clauses Subjunctives in independent clauses are often translated as volitive/optative (that is, as a wish). Volitives/optatives show an intention for an action to occur; e.g. \"amet\" may be translated in volitive/optative context as \"may he love\" #### Hortatory A suggestion or command in first person (most often plural); e.g. \"cedamus\" as an hortatory subjunctive is \"let us depart\" #### Jussive A suggestion or command in third person; e.g. \"cedat\" as a jussive subjunctive is \"let her depart\"; \"deprehendatur\"= \"Let him be seized\" #### Potential The potential or possibility of something happening, in any person: (Fortasse) te amem. \"Perhaps I may love you.\" All of these Subjunctive types can be used in an independent (main) clause. Note that all can be translated with \"let\" or \"may\"; the differences lie in how English will represent the subjunctive verb: - Volitive (Wish): May we be friends forever! - Hortatory (Suggestion): Let us be friends! - Jussive (Command): Let them be friends! - Potential (Possibility): They may be friends; we may be friends; you may be friends. ### Purpose Clauses A purpose clause is a dependent clause used, as the name shows, to show purpose. Often initiated by an indicative verb, the clause contains a subjunctive verb in either the present or imperfect tense. Present and imperfect verbs in purpose clauses should be translated with the auxiliary verbs \"may\" and \"might,\" respectively. For example, \"Marcus urbem condidit ut regeret\" should be translated as \"Marcus built the city so that he would rule.\" These appear frequently in Latin. ### Relative Clauses A relative clause is an independent clause introduced by a relative pronoun. When the verb of a relative clause is in the subjunctive mood the clause may express result, purpose, or characteristic. - Result: The field is so large that he could not plow it in one day. - Purpose: He sent envoys who would pacify the city. - Characteristic: Who is so ill-prepared who would fight without a shield?
# Latin/Lesson 2-Subjunctive Use .The subjunctive mood has several uses in Latin, the most notable of which are: - First Person Exhortations - Purpose Clauses - Result Clauses - Indirect Commands ## First Person Exhortations (Hortatory Subjunctive) ### Definition, Common Usage and Expression in Latin An exhortation is a statement which expresses a wish. In English, the most common exhortation is \"let\'s go\". Other possibilities are \"would go\", \"should go\" and \"may go\". In Latin, these statements are equally as often used and are expressed in the present subjunctive active tense. ### Examples - - - - - ## Purpose Clauses ### Definition, Common Usage and Expression in Latin A purpose clause is a clause which expresses that someone did something in order that something else might happen. In English they usually contain the words in order to or so that. In Latin this concept is expressed by the words ut and ne followed by a verb in the subjunctive mood. Ut means \"so that\" or \"in order to\" and ne means \"lest.\" In purpose clauses, only forms of the imperfect (following the secondary sequence of tenses) and present (for the primary sequence) are used. ### Examples - - - ## Result Clauses ### Definition, Common Usage and Expression in Latin Result clauses state that something occurred as a result of something else happening. For a positive result, use ut. For a negative result, use ut\... non. Result clauses are normally recognisable by a signpost word in the main clause: tam = so (with adjective or adverb) tantus, -a, -um = so big, tot (indecl) = so many talis, -e = such, of such a sort adeo = so much, to such an extent (with verb) ita = so, in such a way (with verb) totiens = so often, so many times (with verb) ### Examples - - - - ## Indirect Commands ### Definition, Common Usage and Expression in Latin An indirect command is a statement like the following: \"He ordered her to do x\". The English equivalent words are \"to\" or \"that they should\" It can also take the form of \"I am ordering you to do x\", as opposed to the imperative \"DO X!\". Several verbs in Latin take the subjunctive mood with indirect commands: 1. rogo, rogare, rogavi, rogatum - to ask 2. persuadeo, persuadere, persuasi, persuasum - to persuade 3. impero, imperare, -imperavi, imperatum - to order 4. peto, petere petivi, petitum - to seek, ask for These verbs use an ut/ne + the subjunctive construction. ### Examples - - - ## Indirect questions ### Definition, Common Usage and Expression in Latin The subjunctive is used in indirect questions. For example, the question \'What are you doing?\' is direct, while \"He asked what I was doing\" is indirect. In Latin, the verb in the clause containing the indirect question must be in the subjunctive. ### Examples - Imperator milites rogat si castra ceperent\ The general asks the soldiers if they captured the camp. - Eum rogo quid faciat\ I am asking him what he is doing. - Magister pueros rogat utrum laborent an ludant\ The teacher asks the boys whether they are working or playing. ## Notā bene! ```{=html} <references/> ```
# Latin/Lesson 6-The Subjunctive Perfect Passive # Subjunctive Passive Verbs ## Subjunctive Passive Perfect Subjunctive passive verbs form from the 4th principle part as shown in the example below. The verb\'s third principle part, e.g. in the word impedire(to obstruct): impedio, impedire, impedivi, impeditus; gains the passive ending for the appropriate person. This is an example of the Subjunctive Passive in the perfect tense. muto, mutare, mutavi, mutatum \-- to change To make the verb into a perfect passive, take the fourth principle part, make it agree with the subject in gender, number, and case, and then add in the appropriate form of esse. In the perfect, we use the present form of esse, and specifically the subjunctive present(sim, sis, sit, simus, sitis, sint.) For example, Do you know what has been done to him? would be made into: scis quid eum factum sit? ` ``Singular` ` mutatus sim ``I have been changed.`\ ` mutatus sis ``You have been changed.`\ ` mutatus sit ``He has been changed.` ` ``Plural`* ` mutati simus ``We have been changed.`\ ` mutati sitis ``You have been changed.`\ ` mutati sint ``They have been changed.` - Note well that in the plural, the word \"mutatus\" becomes \"mutati,\" thus taking on the plural nominative. Remember that the perfect passive verbs require the fourth participle to agree in gender and number! ### Exercises In this section, it is only truly necessary to translate the italicized portion. The rest exists in order to make the subjunctive necessary. the children were so bad that they have been scolded. (Children- Liberi; To scold- vitupero, vituperare, vituperavi) He asked how I was tricked.(trick-ludo, ludere, lusi, lusus) My parents drove to town so that now I have been born in a hospital.(born- cresco, crescere, crevi, cretus; Hospital- valetudinarium, valetudinarii-n.) ## Subjunctive Passive Pluperfect The subjunctive passive pluperfect is very similar to the perfect, with the major difference being the way esse is conjugated. In specific, the word esse is simply given the active endings(m,s,t,mus,tis, nt) mutavi + isse \--\> Singular ```{=html} <!-- --> ``` \mutatus essem I had been changed.\ \mutatus esses You had been changed.\ \mutatus esset He had been changed.* ```{=html} <!-- --> ``` Plural\* ```{=html} <!-- --> ``` \mutati essemus We had been changed.\ \mutati essetis You had been changed.\ \mutati essent They had been changed.* ### Exercises In these exercises, only the italicized parts require translation. The rest exist to make the subjunctive necessary. Remember, the subjunctive is not used in any but complex sentences or other rare circumstances. Ovid wrote so much in the Metamorphoses that his hand had been changed into stone.
# Latin/Lesson 7-The Gerund and Participles # Participles Participles are verbs which function grammatically like adjectives. English, aided by auxiliary participles, is able have participle phrases in many tenses. Latin has participles that do not have auxiliary supplementary participles. This limits the usage of the participle in Latin, according to some wiki-scholars of Classical Studies. ------------------------------------------------------------- `<B>`{=html}`<I>`{=html}Example 1`</I>`{=html}`</B>`{=html} `<B>`{=html}English`</B>`{=html} `<B>`{=html}Latin`</B>`{=html} ------------------------------------------------------------- ## Present Active Participles Present participles are formed by adding -ns to the stem of the verb. ------------------------------------------------------------------- `<B>`{=html}Forming the Present Imperfect Participle`</B>`{=html} 1st Conjugation 2nd Conjugation 3rd Conjugation 4th Conjugation ------------------------------------------------------------------- Present Participles are declined like 3rd declension adjectives. In cases besides the nominative, the -s becomes -t. Examples: 1\. ferens, ferentis 2. capiens, capientis 3. ens, entis ### Exercises Form the Present Participle and translate of the following Latin verbs: - meto, messui, messum, ere - metuo, metum, ui, ere - milito, avi, atum, are - postulo, avi, atum, are - sulco, avi, sulcum, are - iacio, ieci, iactum, ere ### Uses The examples will show participles of the verb amo, amare, amavi, amatum (to love). - present active: base + \'ns.\' This forms a two-termination 3rd declension adjective. In the case of amare, the participle is amans, amantis (loving). - perfect passive: fourth principle part, with appropriate first or second declension endings: amatus, -a, -um. - future active: fourth principle part, minus \'m\', add \'rus, -a, -um\' This forms a 1st-2nd declension adjective: amaturus, -a, -um (about to love). In deponent verbs, the perfect passive participle is formed in the same way as in regular verbs. However, since the nature of the deponent verb is passive in form and active in meaning, the participle is translated actively. Remember that participles are adjectives, and therefore must be declined to agree with the noun which they modify in case, number and gender. ## Gerund The gerund is a verbal noun which is used to refer to the action of a verb. For example: ars scribendi = the art of writing. The gerund is declined as a second declension neuter noun. It is formed by taking the present stem and adding -ndum. ------------ ------------ --------------- -------------- --------------- --------------- Verb amo, amare video, videre rego, regere capio, capere audio, audire Gerund amandum videndum regendum capiendum audiendum ------------ ------------ --------------- -------------- --------------- --------------- \ ==== Meanings of the gerund ==== - Genitive: ars legendi - The art of reading / to read - Accusative: ad puniendum - to punish, for punishing - Ablative: saepe canendo - through frequently singing; in legendo: while reading - Genitive with causa: puniendi causa - in order to punish ## Gerundive The gerundive is a 1st/2nd declension adjective formed the same way as the gerund, and its function overlaps somewhat with the gerund, but otherwise differs. The literal translation of the gerundive is with \"to be\", eg. defendendus, -a, -um = \"to be defended\". - Accusative: ad ludos fruendos - to the games to be enjoyed - to enjoy the games (Note that if this were a gerund construction, it would be ad ludis fruendum since fruor, -i takes the ablative case. In the gerundive construction, both noun and gerundive are governed by the preposition ad) - Gerundive of obligation, which is constructed with the verb \'est\' or \'sunt\', according to the subject\'s number: Carthago delenda est - Carthage is to be destroyed - Carthage must be destroyed. Note that if there is an object (eg. Carthage is to be destroyed by us), it goes into the dative case (eg. Carthago delenda nobis est). # Exercises 1\. Convert the following subjunctive purpose clauses into gerund or gerundive clauses with the same meaning. For example: militabat ut patriam defenderet → militabat ad patriam defendendum or militabat patriam defendendi causa or militabat ad patriam defendendam. Try to use each construction twice. - casam exit ut patrem adiuvet - mater in casam rediit ut cenam pararet - hostes vincebant ergo scutum abieci (I threw away my shield) ut celerius fugerem - in silvas currimus ut nos celemus - hostes in silvas ineunt ut nos invenirent - Brutus Iulium Caesarem occidit ut Romam liberaret 2\. Translate into Latin. For example: I must see the temple -\> templum mihi videndum est - We must build a large city. - Julius Caesar must lead an army into Greece. - Scipio (Scipio, -ionis) must defeat Hannibal.
# Latin/Lesson 8-Conditional Clauses ## Conditional Clauses Conditional clauses in English and Latin have the general form: `<b>`{=html}if`</b>`{=html} (condition clause) (result clause) Or: (result clause) `<b>`{=html}if`</b>`{=html} (condition clause) For example: 1. If I see anyone, I\'ll tell you. 2. If he was sleeping, you should not have knocked. 3. I cannot hear you if I\'m sleeping. 4. I would have been sad if I had not won. There are 3 types of conditional clauses in Latin: 1. Simple Fact (Present or Past) 2. Contrary to Fact (Present or Past) 3. Future (More or Less Vivid) ### Simple Fact Conditionals Simple fact conditionals in Latin have the general form: si (condition clause in the present indicative) (result clause in the present indicative) Or: si (condition clause in the imperfect/perfect indicative) (result clause in the imperfect/perfect indicative) =====For <example:=====> `<i>`{=html}si diligenter laboras, bonus puer es`</i>`{=html} If you are working diligently, you are a good boy. `<i>`{=html}si dominum adiuvabas, bonus servus eras`</i>`{=html} If you were helping your master, you were a good slave. ### Contrary to Fact Conditionals Contrary to fact conditionals are used if the condition clause is known to be false. For example: If you weren\'t playing during class, you would be a good boy (but you were playing, so you aren\'t a good boy). Contrary to fact conditionals have the general form: si (condition clause in the imperfect subjunctive) (result clause in the imperfect subjunctive) Or: si (condition clause in the pluperfect subjunctive) (result clause in the pluperfect subjunctive) =====For <example:=====> `<i>`{=html}si matrem adiuvaret, cena parata esset`</i>`{=html} If he were helping his mother, the dinner would be ready. `<i>`{=html}si patrem adiuvisset, pater matrem adiuvare potuisset`</i>`{=html} If he had helped his father, his father would have been able to help his mother. Note how English uses `<b>`{=html}would`</b>`{=html} and `<b>`{=html}would have`</b>`{=html} for result clauses, while Latin uses the same tense as in the condition clauses. ### Future Conditionals Future conditionals are, of course, used to express conditions in the future. For example: If you help me, I will be done faster. Future conditionals take the following general form: si (condition clause in the future or future perfect) (result clause in the future) Or: si (condition clause in the present subjunctive) (result clause in the present subjunctive) =====For <example:=====> `<i>`{=html}si fortiter pugnaveritis, urbs non delebitur`</i>`{=html} If you fight bravely, the city will not be destroyed. Note how English uses the present tense for the condition clause, while Latin uses the future or future perfect. `<i>`{=html}si diligenter laboretis, vobis meridie domum dimittam`</i>`{=html} If you were to work diligently, I would dismiss you at noon. This type of clause, known as the future less vivid (as opposed to the future more vivid which uses the future and future perfect), is used to express more improbable conditions in the future.
# Latin/Chapter 4 Verse Haec est fabula De Faciebus Iani. Ianus, ut dicebatur, erat unus deorum, cui facies duae erant. Altera earum enim in futura et altera in praeterita prospiciebat. Apollo ei olim sic dixit: \"Nonne tibi facies est, qua tempus praesens spectes?\" Et paulo post Ianus ita respondit: \"Mundus - orbis terrarum cyclus est similiter ac tempus est cyclicum. Et initium omnium et finem video. Omnia prospicio aeternusque sum, neque opus est porro videre, quae palam iaceant.\" Diu cogitavit Apollo de verbis Iani hominesque acutissimā mente in omni orbe terrarum conquaesivit eo consilio, ut ipse tam sapiens ut Ianus fieret. Postea cum quibusdam illustrissimis viris collocutus est, quo sapientior esset. Eo facto tamen unus eorum, cui Minervus nomen, Apollinem monuit, ne summam quaereret sapientiam, quam novisse nullum alium quam Ianum oportebat. Revenit autem Apollo ad Ianum eumque, ut veritatem cognosceret, ea summa rogavit. \"Intellegisne omnino quid roges?\" inquit Ianus, \"Si dis par fueris, omnibus iuribus privari possis.\" Itaque Apollo cognovit sapientissimum omnium fuisse, a quo monitus est. Translation below: This is the story of the faces of Janus. Janus, as it used to be said, was one of the gods who had two faces. It was that one spied into the future while the other into the past. Apollo once had said to him, \"Have you not a face with which to see the present?\" After a few moments, thus spoke Ianus: \"The world is a circle. Time is a circle. I see both the beginning and end of all living things. I am foreseeing and eternal; therefore, it is not necessary for me to see that which is lying out of sight.\" Apollo thought about these words for a very long time, and thus, that he might become wise like Janus, he sought the keenest minds of the land. He then was speaking with some great men that he might become wiser. However, one, whose name was Minervus, warned him not to seek the ultimate/highest truth because it may only be known by Janus. But he returned again to ask Janus that he might obtain the truth. \"Do you even know for what you\'re asking? If you enter onto the same level (of the Gods), all your rights might be snatched from you,\" said Janus. And so Apollo knows now that the same man who had warned him was the wisest of all.
# Latin/Chapter 5 Verse \< Latin ## A Verse From the Gospel of St. Luke Respondens Simon dixit: \"Aestimo quia is, cui plus donavit\". At ille dixit ei: \"Recte iudicasti\". Et conversus ad mulierem, dixit Simoni: \"Vides hanc mulierem? Intravi in domum tuam: aquam pedibus meis non dedisti; haec autem lacrimis rigavit pedes meos et capillis suis tersit. Osculum mihi non dedisti haec autem, ex quo intravi non cessavit osculari pedes meos. Oleo caput meum non unxisti; haec autem unguento unxit pedes meos. Propter quod dico tibi: Remissa sunt peccata eius multa, quoniam dilexit multum: cui autem minus dimittitur, minus diligit.\" Dixit autem ad illam: \"Remissa sunt peccata tua\". Et coeperunt, qui simul accumbebant, dicere intra se: \"quis est hic, qui etiam peccata dimittit?\". Dixit autem ad mulierem: Fides tua te salvam fecit; vade in pace!\".
# Latin/Lesson 9-Poem _A Poem by Catullus_ I. ad Cornelium `<poem>`{=html} cui dono lepidum nouum libellum arida modo pumice expolitum. Corneli tibi namque tu solebas meas esse aliquid putare nugas iam tum cum ausus es unus Italorum omne aeuum tribus explicare cartis doctis Iuppiter et laboriosis. quare habe tibi quidquid hoc libelli qualecumque quidem est. patroni et ergo plus uno maneat perenne saeclo. `</poem>`{=html} 1. to Cornelius `<poem>`{=html} To whom do I send this fresh little book of wit, lately polished dry with pumice stone? To you, Cornelius: since you were accustomed to consider my trifles worth something even then, when you alone of Italians dared to explain all the ages, in three learned works, by Jupiter, and with the greatest labour. Then take this little book for your own: whatever it is, and is worth: virgin Muse, patroness, let it last, for more lives than one. `</poem>`{=html} _Notes_ Title: ad Cornelium Ad is a Preposition meaning \"to\" and therefore never changes case. The name Cornelius is a second declension masculine noun. Names are declined the same as any other noun. You need only decline the singular since there is only one Cornelius.\ Nom. Cornelius\ Voc. Corneli\ Acc. Cornelium\ Gen. Cornelii\ Dat. Cornelio\ Abl. Cornelio\ The translation is \"To Cornelius\". The Preposition \"ad\" is only used with the Accusative Case. The Accusative Case is the same as the English Object Case. Second declension male names ending 'ius' have the double 'ii' form in the genitive. Line One: Cui dono lepidum nouum libellum?
# Latin/Spoken This chapter\'s purpose is to demonstrate hands-on spoken latin using dialogues, word lists, colloquial expressions and all that is needed to grasp spoken latin. It is recommended that you cover all verb, adjective and noun endings and have read through the rest of the Latin book, or at least the revision pages, before you embark on this. Subjunctive, infinitive and indicative all need to be well understood in order to complete this course. At the end of every exercise there will be a show-hide exercise and sometimes an English-Latin translation. There will often be referenced footnotes showing where there have been quotes from original Latin authors and tips to usage of sentences. ## Introduction Latin as a language was spoken from its earliest origins all through the middle ages to the renaissance and beyond by numerous students, scholars and the educated nobility. Like all spoken languages, Latin evolved in vocabulary and form. Often the vernacular languages influenced how Latin was spoken. While there were many attempts to stay true to Ciceronian form in speech and writing by scholars, most when they spoke the Latin tongue used forms and vocabulary often derived from their mother tongue which would have been incomprehensible to Classical speakers. Latin grammar has remained fixed and unchanged for centuries. The two most controversial issues about the living use of Latin (living Latin) are pronunciation and the introduction of new words. Regarding modern vocabulary, many schools exist, and there is no consensus as yet. The Roman Catholic Church publishes a lexicon (Lexicon Recentis Latinitatis) with an exhaustive number of modern words translated into Latin; often this is done through cumbersome periphrases (e.g. a hippie is 'osor conformitatis') and other times by arbitrary coinage of new words. ### Pronunciation When speaking Latin, the choice is usually between 'ecclesiastical' pronunciation and 'classical' pronunciation. The 'ecclesiastical' pronunciation nowadays usually refers to the Italian pronunciation of ecclesiastical or 'Church' Latin, which is still the official liturgical language of the Catholic Church. Desiring uniformity, this Italian pronunciation is often encouraged as the standard for Masses celebrated in the Latin language. It is however only one of many regional systems of pronunciation. An example of the Italian pronunciation can be found in this video. 'Classical' pronunciation, like the Italian pronunciation, offers consistency of sound across national borders. It also aims to be a scholarly reconstruction of how ancient Romans spoke, or at least educated speakers of the late Republican/early imperial period. It is described in books such as the paradigmatic Allen\'s Vox Latina. An example of classical Latin pronunciation can be found in this video. The sound of the classical pronunciation, in particular the replacement of the 'v' sound with the 'w' sound, has been the subject of controversy. It is, however, the clear favorite of the 'Living Latin' movement, which has the fastest growing number of new speakers of the language. ## Lessons - Basic conversations - Telling people where you\'re from and what language you speak ## Revisions - /Revision 1/ - /Revision 2/ - /Revision 3/ ## Assessments - /Test 1/ de:Latein/ Gesprochenes Latein
# Latin/Verb Synopsis Here The Verb Amo, Amare, Amavi, Amatus Is Conjugated In The Second Plural ------------------------------------------------------------------------ Active Indicative Amatis Amavistis Amabatis Amaveratis Amabitis Amaveritis Passive Indicative Amamini Amati Estis Amabamini Amati Eratis Amabimini Amati Eritis Active Subjunctive Ametis Amemini Amaretis Amaremini Amaveritis Amati Sitis Amavissetis Amati Essetis Positive Imperative Ama (Active singular) Amate (Active plural) Amare (Passive singular) Amamini (Passive plural) Negative Imperative Noli Amare (Singular) Nolite Amare (Plural) Participles Amans (Present Active) Amatus (Perfect Passive) Amaturus (Future Active) Amandus (Future Passive) Infinitives Amare Amari Amavisse Amatus esse Amaturus esse Amatum iri Supines Amatum (To Show Purpose) Amatu (Used With Adj. Like An Infinitive) ------------------------------------------------------------------------
# Latin/Index II `<big>`{=html}*This Page is incomplete`</big>`{=html}\ For explanations of terms used in these grammar tables, check the Glossary. ## Declension of Nouns ### 1st Declension Masculine (each word has a set gender) puella 1st Declension Singular Plural ---------------- ---------- ------------ nominative puell-a puell-ae vocative puell-a puell-ae accusative puell-am puell-as genitive puell-ae puell-arum dative puell-ae puell-is ablative puell-a puell-is ### 2nd Declension Masculine/Feminine (each word has a set gender): servus 2nd Declension Masculine Singular Plural -------------------------- ---------- ----------- nominative serv-us serv-i vocative serv-e serv-i accusative serv-um serv-os genitive serv-i serv-orum dative serv-o serv-is ablative serv-o serv-is ### 2nd Declension Neuter: bellum 2nd Declension Neuter Singular Plural ----------------------- ---------- ----------- nominative bell-um bell-a vocative bell-um bell-a accusative bell-um bell-a genitive bell-i bell-orum dative bell-o bell-is ablative bell-o bell-is ### 2nd Declension Masculine: puer 2nd Declension Masculine Singular Plural -------------------------- ---------- ----------- nominative puer puer-i vocative puer puer-i accusative puer-um puer-os genitive puer-i puer-orum dative puer-o puer-is ablative puer-o puer-is ### 2nd Declension Masculine: ager 2nd Declension Masculine Singular Plural -------------------------- ---------- ---------- nominative ager agr-i vocative agr-e agr-i accusative agr-um agr-os genitive agr-i agr-orum dative agr-o agr-is ablative agr-o agr-is ### 3rd Declension Masculine or Feminine (each word has a set gender): rex 3rd Declension Singular Plural ---------------- ---------- ---------- nominative rex reg-es vocative rex reg-es accusative reg-em reg-es genitive reg-is reg-um dative reg-i reg-ibus ablative reg-e reg-ibus ### 3rd Declension Neuter: mare 3rd Declension Neuter Singular Plural ----------------------- ---------- ---------- nominative mar-e mar-ia vocative mar-e mar-ia accusative mar-e mar-ia genitive mar-is mar-ium dative mar-i mar-ibus ablative mar-i mar-ibus ### 4th Declension Masculine/Feminine (each word has a set gender) gradus 4th Declension Singular Plural ---------------- ---------- ----------- nominative grad-us grad-us vocative grad-us grad-us accusative grad-um grad-us genitive grad-us grad-uum dative grad-ui grad-ibus ablative grad-u grad-ibus ### 4th Declension Neuter: cornu 4th Declension Neuter Singular Plural ----------------------- ---------- ----------- nominative corn-u corn-a vocative corn-u corn-a accusative corn-u corn-a genitive corn-us corn-uum dative corn-ui corn-ibus ablative corn-u corn-ibus ### 5th Declension Masculine/Feminine (each word has a set gender): res 5th Declension Feminine/Masculine Singular Plural ----------------------------------- ---------- -------- nominative r-es r-es vocative r-es r-es accusative r-em r-es genitive r-ei r-erum dative r-ei r-ebus ablative r-e r-es : m* = masculine\ : f = feminine\ : n - neuter NOTES 4/5th declensions are modified 3rd declensions, thus behave similarily. 3rd declension is either M/F/N, 4th declension is either M/F/N and 5th declension is either M/F. So for 3rd, 4th, and 5th declension is of most importance to memorise the gender because the adjective will still need to agree (ie have the same) with the noun in both case, gender, and number. The Vocative only changes for the 2nd declension masculine singular (however not for the nouns that leave the -us suffix when in nominative). There are a few exceptions in the 1st declension which are not feminine. Such nouns are poet-a (1st declension masculine, so to agree you need to use -us on the adjective) and naut-a. There are a few second declension nouns with irregularities. It is of most importance that you memorise them. When memorising a noun\'s meaning, make sure that you also memorise any irregularities the noun has, the gender, and the declension. Without doing this you may have trouble translating. For example, 2nd declension masculines have -us in the nominative singular; however, 4th declension masculines have -us in the nominative singular, nominative plural and accusative plural. This may get you confused if you do not memorise the declension of each noun. ## Single Declension Theory If you look at the above list of declensions, you may feel that you are going to be overcome if you have to memorize all of it. Memorization is indeed the key, but it will be easier than you think. Each word in Latin has three parts: the root, the stem vowel, and the ending. There are five vowels in Latin, so there are five stem vowels: A,O,I,U,E. Any word not really having a stem vowel naturally was given to I. If you study the declension patterns enough you will see that there are many similarities in the declensions. All accusative singulars end in \"m\" except neuters that sometimes still do. All accusative plurals end in \'s\' except neuters that always end in a. All genitive plurals end in \"um\", be it ium, rum, uum or whatever else. If you read enough Latin you will actually find that authors would switch a declension of a word at will if it made the sentence clearer. Thus many words that are of the 4th declension were sometimes written as if 2nd, and 5th declension as if 3rd and vice versa. Some ending patterns that we use for one declension may also be used in another, again to make the sentence clearer. Thus \"filiabus\" would be used in any sentence where we want to make it clear that we are talking about the Daughters and specifically not the Sons. We also see examples of this in animabus. Some think that the IS used in the first and second declensions was actually an abbreviation of bus. Some students find the ablative difficult since it sometimes looks like the nominative singular, dative plural or neither. All you really need to do to get the hang of this is to know that in the plural, the ablative always looks like the dative. If there is no preposition in front of it then it is probably a dative, unless it is being used in an ablative construction that would likely be apparent. If there is a preposition and it looks like a dative, just remember that no preposition takes a dative, only ever ablative and sometimes accusative. Dative plural plus preposition equals ablative. The ablative singular is really just the root plus the stem vowel with no ending to speak of, since the preposition tells you the grammar of the word. Some students also get confused by words that are the same in the nominative singular and plural. Don\'t worry about that; the verb will tell you which it is since the verb always agrees with the nominative. It is thought that originally there was only one declension, but during the task of applying it to every word in natural speech it was found that some words naturally changed the way the basic sounds of the original declension worked. Here is one idea of the original basic declension. Case Root Stem Vowel Singular Plural ------------ ------- ------------ ---------- -------- nominative puell a None es genitive puell a is rum dative puell a i bus accusative puell a m s ablative puell a none bus When speaking in everyday conversation, Latin speakers would shorten the word in their pronunciation so long as it still made sense. If you go to New Orleans you will likely hear someone say \'prowly\'. This is not a new dish at a restaurant or a new new code name for the police, it is actually the local pronunciation of the word probably. It is ok to shorten this word because when it is shortened everyone can still understand it. The Latins did the same thing. It is known that I can change to E and vice versa, so we can see that pattern in the dative singular of all declensions. The IS of the genitive was kept in the 3rd declension, shortened in the 1st, 2nd, and 5th and slightly altered in the 4th. The \'add M\' rule of the accusative singular is seen in the altering of the stem vowel in the 2nd and 3rd declensions. The ES of the nominative plural became E in 1st, I in 2nd, and US in 4th. The RUM of the genitive plural was shortened in the 3rd and 4th declensions. The accusative plural as a rule never changes, but keep in mind that neuter words followed a different pattern of using A for the accusative plural, and all neuters took the accusative singular or plural for the nominative of the same number. The BUS of the dative/ ablative plural was shortened to IS in the 1st and 2nd declensions but kept in the others. The 4th declension has a tendency to copy the IBUS of the 3rd in some authors but retain the UBUS in others. When studying Latin declensions you really should strive to memorize the patterns, but also look to see how they are similar to other patterns in the language as it will help you to remember. Also note that the IS of the genitive singular is what eventually gave us the word HIS and the \'add \'s\'\" rule of English. Latin also gave us the \'add \'s\'\" to make a plural by way of the accusative plural. If you study other inflexive languages related to Latin, such as Greek, you will notice even similarities across languages.
# Latin/Accents and Scansion All latin syllables are either long or short and stressed or unstressed. The metre of Latin poetry, unlike English poetry, is dependent on the length of the syllables rather than their accent. ### Length The two different lengths for syllables are long (indicated by a macron ˉ ) and short (indicated by a breve ˇ ). All syllables are either one or the other. A syllable's length is determined by both its nature and its position. If a syllable is long by nature that means that the vowel sound is long and pronounced differently to its short counterpart (e.g.). ---------------------------- ā is pronounced as in cart ă is pronounced as in cut ---------------------------- On the other hand, if a syllable is long by position, the consonants around the vowel sound determine the syllables length, rather than the syllable itself. If a vowel is followed by two consonants, then the syllable will be long irrespective of the nature of the vowel. The following line is from Poem 1 by Catullus in hendecasyllables. --------------------------------- cuī dōnō lĕpĭdūm nŏvūm lĭbēllŭm --------------------------------- The long syllable at the end of novum is caused by the two consonants (m and l) following it whereas the long syllable at the end of dono has to be long by nature as there is only one consonant following it. ### Stress As well as long and short syllables Latin also has a stress accent, like English. This is where the natural emphasis goes when speaking. The stress accent is determined by the length of the syllables but not the same as it. Unlike English there are fairly consistent rules to work out where the stress accent is placed in Latin words. ------------------------------------------------------------------------------------------------------------------------------- 1\) For words of two syllables, the accent usually goes on the second last syllable. 2\) For words of more than two syllables where the second last syllable is long, the accent goes on the second last syllable. 3\) For words of more than two syllables where the second last syllable is short, the accent goes on the third last syllable. ------------------------------------------------------------------------------------------------------------------------------- These rules are demonstrated in the following words taken from the extract above:\ ------------------ 1\) nŏvūm 2\) lĭbēllŭm 3\) lĕpĭdūm ------------------ ### Poetic Meter As mentioned, Latin poetry depends on the length of syllables rather than their stress accent. A line of Latin verse is divided into feet depending on the pattern of long and short syllables. The pattern of feet then determines the meter. In some poetic meters, such as dactylic hexameter, there is also a main caesura in every line written as (˄). This is caused when there is a break in words in the middle of a foot.
# Latin/Common phrases ## Latin (Italic) Pronunciations are first given in the Ecclesiastical Pronunciation (Based on Italian, and used in some ceremonies by the Catholic church, and usually heard in recordings of classical music). These pronunciations are followed by the classical pronunciation (a reconstruction of how scholars believe the Romans pronounced these expressions) For example --- "of light" lucis (LOO-cheess) (LOO-kiss), with (LOO-cheess) being the ecclesiastical pronunciation, and (LOO-kiss) how the Romans said lucis. +----------+----------+----------+----------+----------+----------+ \| Tra \| Latin \| IPA \| Pseudo \| IPA \| Pseudo \| \| nslation \| \| (Eccles \| -English \| (Cl \| -English \| \| \| \| astical) \| \| assical) \| \| +==========+==========+==========+==========+==========+==========+ \| Latin \| lingua \| ```{=me \| (lah- \| ```{=me \| (lah- \| \| \| Latina \| diawiki} \| TEE-nah) \| diawiki} \| TEE-nah) \| \| \| \| { \| \| {{ \| \| \| \| \| {IPA\|/'l \| \| IPA\|/'li \| \| \| \| \| ingwa la \| \| ngwa la' \| \| \| \| \| 'tina/}} \| \| tiːna/}} \| \| \| \| \| ``` \| \| ``` \| \| +----------+----------+----------+----------+----------+----------+ \| hello \| ave! \| ```{=me \| (Ah-vay) \| ```{=me \| (Ah-way) \| \| \| \| diawiki} \| \| diawiki} \| \| \| \| \| {{IPA\| \| \| {{IPA\|/ \| \| \| \| \| /'ave/}} \| \| 'aweː/}} \| \| \| \| \| ``` \| \| ``` \| \| +----------+----------+----------+----------+----------+----------+ \| welcome \| salve! \| ```{=me \| ( \| ```{=me \| ( \| \| \| \| diawiki} \| Sal-vay) \| diawiki} \| Sal-way) \| \| \| \| {{IPA\|/ \| \| {{IPA\|/s \| \| \| \| \| salve/}} \| \| alveː/}} \| \| \| \| \| ``` \| \| ``` \| \| +----------+----------+----------+----------+----------+----------+ \| goodbye \| vale! \| ```{=me \| ( \| ```{=me \| ( \| \| \| \| diawiki} \| vah-lay) \| diawiki} \| wah-lay) \| \| \| \| {{IPA\|/ \| \| {{IPA\|/' \| \| \| \| \| 'vale/}} \| \| waleː/}} \| \| \| \| \| ``` \| \| ``` \| \| +----------+----------+----------+----------+----------+----------+ \| please \| si \| ```{=me \| (see \| ```{=me \| (see \| \| \| placet \| diawiki} \| PL \| diawiki} \| P \| \| \| \| {{IP \| AH-chet) \| {{IPA \| LAH-ket) \| \| \| \| A\|/si 'p \| \| \|/siː 'p \| \| \| \| \| laʧet/}} \| \| lakɛt/}} \| \| \| \| \| ``` \| \| ``` \| \| +----------+----------+----------+----------+----------+----------+ \| thank \| gratias \| ```{=me \| (GRAH \| ```{=me \| (GRA \| \| you \| tibi ago \| diawiki} \| -tsee-as \| diawiki} \| H-tee-as \| \| \| \| {{IPA\| \| TI-bee \| {{IPA\|/' \| Ti-bee \| \| \| \| /'gratsi \| AH-goh) \| graːtiaː \| AH-goh) \| \| \| \| as 'tibi \| \| s 'tibi \| \| \| \| \| 'ago/}} \| \| 'agoː/}} \| \| \| \| \| ``` \| \| ``` \| \| +----------+----------+----------+----------+----------+----------+ \| that one \| ille/ \| ```{=me \| ( \| ```{=me \| ( \| \| \| illa/ \| diawiki} \| ILL-lay, \| diawiki} \| ill-leh, \| \| \| illud \| {{IPA\| \| ILL-lah, \| {{IPA\| \| ill-lah, \| \| \| \| /'ilːe, \| I \| /'ilːɛ, \| i \| \| \| \| 'ilːa, ' \| LL-lood) \| 'ilːa, ' \| ll-lood) \| \| \| \| ilːud/}} \| \| ilːud/}} \| \| \| \| \| ``` \| \| ``` \| \| +----------+----------+----------+----------+----------+----------+ \| how \| quot? \| ```{=me \| (quote) \| ```{=me \| (quote) \| \| much? \| \| diawiki} \| \| diawiki} \| \| \| \| \| {{IPA\| \| \| {{IPA\| \| \| \| \| \| /kwot/}} \| \| /kwot/}} \| \| \| \| \| ``` \| \| ``` \| \| +----------+----------+----------+----------+----------+----------+ \| yes \| certe, \| ```{=me \| (CH \| ```{=me \| ( \| \| \| ita vero \| diawiki} \| AIR-tay) \| diawiki} \| ker-tay) \| \| \| \| {{IPA\|/' \| \| { \| \| \| \| \| ʧerte/}} \| \| {IPA\|/'k \| \| \| \| \| ``` \| \| ɛrteː/}} \| \| \| \| \| \| \| ``` \| \| +----------+----------+----------+----------+----------+----------+ \| no \| non, \| ```{=me \| (noan, \| ```{=me \| (known, \| \| \| nullo \| diawiki} \| NUL-loh \| diawiki} \| NUL-oh \| \| \| modo \| {{IP \| MO-doh) \| {{IPA\|/ \| MO-doh) \| \| \| \| A\|/'non, \| \| 'noːn, ' \| \| \| \| \| 'nulːo \| \| nuːlːo ' \| \| \| \| \| 'modo/}} \| \| mɔdoː/}} \| \| \| \| \| ``` \| \| ``` \| \| +----------+----------+----------+----------+----------+----------+ \| sorry \| ignosce \| ```{=me \| (een- \| ```{=me \| (ing-k \| \| \| mihi \| diawiki} \| YOH-shay \| diawiki} \| now-skeh \| \| \| \| {{IPA\| \| MEE-hee) \| { \| Mi-hee) \| \| \| \| /i'ɲoʃe \| \| {IPA\|/i' \| \| \| \| \| 'mihi/}} \| \| ŋnoːskɛ \| \| \| \| \| ``` \| \| 'mihi/}} \| \| \| \| \| \| \| ``` \| \| +----------+----------+----------+----------+----------+----------+ \| I don't \| non \| ```{=me \| (noan \| ```{=me \| (known \| \| un \| com \| diawiki} \| c \| diawiki} \| c \| \| derstand \| prehendo \| {{ \| om-pray- \| {{IP \| om-pray- \| \| \| \| IPA\|/noŋ \| HEN-doh) \| A\|/noːŋ \| HEN-doh) \| \| \| \| kompre' \| \| komprɛ'h \| \| \| \| \| hendo/}} \| \| ɛndoː/}} \| \| \| \| \| ``` \| \| ``` \| \| +----------+----------+----------+----------+----------+----------+ \| where\'s \| ubi sunt \| ```{=me \| (OO-bee \| ```{=me \| (OO-bee \| \| the \| l \| diawiki} \| soont \| diawiki} \| soont \| \| b \| atrinae? \| {{IP \| lah-T \| {{IPA\| \| lah-t \| \| athroom? \| \| A\|/'ubi \| REE-nay) \| /'ubi su \| ri-neye) \| \| \| \| sunt la' \| \| nt la'tr \| (neye \| \| \| \| trine/}} \| \| iːnai/}} \| rhyming \| \| \| \| ``` \| \| ``` \| with \| \| \| \| \| \| \| eye) \| +----------+----------+----------+----------+----------+----------+ \| generic \| salutem! \| ```{=me \| (sah-L \| ```{=me \| (sah-L \| \| toast \| \| diawiki} \| OO-taym) \| diawiki} \| OO-tehm) \| \| \| \| {{ \| \| {{ \| \| \| \| \| IPA\|/sa' \| \| IPA\|/sa' \| \| \| \| \| lutem/}} \| \| luːtɛ̃/}} \| \| \| \| \| ``` \| \| ``` \| \| +----------+----------+----------+----------+----------+----------+ \| Do you \| lo \| ```{=me \| (l \| ```{=me \| (l \| \| speak \| querisne \| diawiki} \| oh-quay- \| diawiki} \| oh-queh- \| \| English? \| anglice? \| {{IPA\| \| RISS-nay \| {{IPA\|/ \| riss-neh \| \| \| \| /lokwe'r \| AHNG-gle \| lɔkwɛ'ri \| ahng \| \| \| \| isne 'aŋ \| e-chay?) \| snɛ 'aŋg \| li-kay?) \| \| \| \| gliʧe/}} \| \| likeː/}} \| \| \| \| \| ``` \| \| ``` \| \| +----------+----------+----------+----------+----------+----------+
# Latin/Spoken Latin ## Audio Files Hi, if you want to learn spoken Latin some of the wide range of lessons on the Latinum podcast are aimed at this: have a look at <http://latinum.mypodcast.com> ## Code Switching Trick Here is a trick you can use to learn both basic grammar and to get into the hang of speaking in Latin. One of the biggest problems for students who learn Latin is the fact that it is not a word order language. This fact has already been covered in other lessons but the trick presented here is designed to get you past word order thinking and to start producing Latin in your head so it can come out of your mouth or off of your pen. Please note that if you don\'t have enough vocabulary to produce a real sentence in Latin with out looking up every word you can still use this trick to get yourself used to speaking in this way but using English words that you will slowly replace as your Latin vocabulary grows. I\'d not use this method for more than a day or so. But playing around with it will help a little. Nothing will really work, except for working and studying Latin itself, in Latin. Of course if you have studied the proper endings for a word then you should use it but if not just keep the English pronouns He, His, Him in you mind. Using these in English it is possible to violate English strict word order and still create an intelligible sentence. : He to her its them gives. Of course this is not good English and we don\'t know what the pronouns are referring to but we can still understand and that is the whole point. Using pronouns in English we can violate word order and even leave it behind. The interesting thing about Latin is that it isn\'t just the Pronouns but every word with few exceptions that can do this. This is what you do. Any word, from any language can be Latinized and used in a pseudo language that will teach you to speak Latin if you stick with it. Subject of a sentence: do nothing to the word but keep in mind that you can actually drop it from the sentence if everyone already knows what you are talking about. Possessive: add an \`IS\` to the end of the word, so instead of car\'s, you will have caris. Indirect object: add \`i\` to the end. This will sound funny but will work. If a word end in an ee kind of sound just pronounce it twice. Direct object: add \`EM\` to the end of a word. thus you get things like flowerem, spacem, computerem, carem, personem and so on. If you need to use a preposition just use the prepositions you have learned and don\'t change the word (just use the subject form as the preposition tell you the grammar of the word) Thus you could say a sentence like; : boy girli manis flowerem gives The above sentence is not English, nor Latin but it is what is called Code Switching and anyone who is on the way to fluency in a second language does it automatically. That is why is Japan people go around saying things like : Car WA Boy OH Hit imasu. We don\'t understand this sentence but it again is what may happen when two languages mix in the brain. Code Switcing is an important step to really becoming efficient in a new language. It allows you to move past only translation and actually make words come out of your mouth. Note; when you practice this trick don\'t worry about the plurals till you really study them. Anyone who has studied Latin even a little probably knows the beginnings of the conjugation for : amo, amas, amat What you should take note of is the fact that where the second person in Latin is governed by an S at the end and the third by a T it is reversed in English. : I love, thou lovest, he loves So this is what you do to start adding Verbs to your new Latin Code Switching hack; flip what you would normally say for HE from S to T at the end and start using S for the You form. : I love, you loves, he lovet Yes, It looks strange but it is to help you learn to code switch. Again, don\'t use plurals till you really learn them and have already gotten used to using the singulars here. When you learn the correct Latin Vocabulary then replace the English words for the correct Latin words with correct Latin endings for that particular word. As a final step before really forcing yourself into creating all Latin sentences, start using either an \`M\` or an \`I\` after verbs that are in the first person : I lovem, I lovei This will be important when you learn the perfect tense. Then start dropping the I, we, you, them pronouns all together. You will find that you don\'t need them since the verb tells you who is doing the action of the verb. Still use He and she as the difference from Male and Female is more important in Latin then in English. Your resulting sentences should be something like this when spoken : boy girli manis flowerem givet. Don\'t write in this code. This should be used only for spoken exercises. Get a friend and both of you learn this code and just speak back and forth. Keep it simple. Don\'t try anything too complicated till you actually learn it. Try to make it sound nice as well, Latin was a fluid, beautiful language that gave use the romance of French and Italian so giving yourself a little accent can\'t hurt. Another tip is to put the verb at the end of the sentence. The reason is that this creates a spoken period. Because we don\'t have word order to tell us when the sentence ends anymore, by putting the verb, which every sentence must have, at the end you are also telling the other person that the sentence is coming to an end. To make a question you can still put the verb at the end and just make it sound like a question or use a prober Latin question creator when you learn it. Here is an example of a conversation in this code : computerem uses? : yes. use wants? : dog momis computerem broket. : really, terrible ist. : mom around house dogem chaset : funny soundt : say, girlis from computer class numberem gets? : no, she tall guyem liket : dark hairem she liket? : Maybe, not knowi : heris numberem get tryi Yes, silly conversation, but this is just to give you an example of how to start breaking word order grammar and get into the mindset of the inflexive Latin grammar. Once you learn the proper endings start applying them to your English words. When you learn the proper vocabulary then switch to using the Latin words. When you learn a new Verb ending for past tense, infinitive and what not then start practicing with this new ending till you got it down, and not just with Latin words but with English Code Switching. You will be able to speak intelligible, near fluent Latin in less than five months. Once you actually do get some real Latin vocabulary under your belt you should start paying attention to the grave marks. Macrons can help you to tell the difference in words in their written form but really doesn\'t help with speaking. Find a book or article in the net that shows the little accent markes that are sometimes called graves and sometimes called Breves. They look like just a little slash over a vowel. é é à and the like. These tell you what part of the word to sort of choke up on. Try saying the word Spaghetti. You automatically want to choke up or stress the E sound in the middle. You actually say this \`spaghétti\`. Not all words have a stressed sound in them but many do and it can give you a great way to really sound Latin. All in all they are really helpful. Many speakers of Latin will change a C to a CH if it is followed by an E or I vowel sound. You don\'t have to do this and many people that teach Classical Latin say it is wrong but if you are speaking Latin today it really is by definition Not Classical Latin. Doing this will get you saying the word in a very European kind of pronunciation that really seems very natural and makes some words easier to say. Again, you don\'t have to do it and really shouldn\'t if it makes your teacher angry. Similar to changing the C to CH is the use of changing a G sound to a J sound if again followed by an E or an I sound. : Thus Ge-nu becomes \`jen-u as in the modern genuflect. : Civitas- Kee vee tas becomes Chee vee tas which eventually came to be See vee tas- so that we can say civics and citizen. The last point of concern is to choose to use the letter V as a v,v,v,v,v,v,v sound or a W,W,W,W,W,W sound. Once you pick it is best to stay consistent and not change from one word to another. If you don\'t like the way it is going with one and want to change to the other then change all words to the new way of saying them. ## Sentence patterns Once you have played around with the language a bit you will want to start putting things in order the way they should be in Latin. Now, it is true that Latin does not have a specifically set word order, but there is a usual order that sentences tend to go in. This does not mean that they HAVE TO go in this order, it just is the common way. The word order, it should be remembered, has zero relation to the grammatical meaning of a word. Regardless of word order the sentence will mean the exact same thing. However the normal word order goes something like this. Nominative Dative Accusative Ablatives/Adverbs Verbs. Put into modern English language grammatical terms, this translates into something like this. Subject Indirect Object Direct Object Compliments verbs. Please note, the verb is usually last. It does not have to be, but just usually is. The subject (nominative) is usually first but does not have to be and an interesting feature of Latin is that the Subject can be dropped anytime it is understood. Many sentences in Latin actually wind up being Direct Object Verb. The reason most teacher teach the declention list in a certain order N-G-D-Ac-Ab is because of this normal Latin word order even if they do not realize it. Most Latin sentences will not contain every case. Latin has a number of sentence patterns and these patterns determine what cases are needed and what those cases mean. The most basic sentence pattern in Latin is Nominative Esse. For this sentence pattern you basically put your noun in the nominative case and put the correct form of the \"be\" verb Esse after it. Examples:\ :Homo sum. Mulier es. Umbella est. Pueri sumus. Puellae estis. Furnaces sunt. Make sure you match singulars with singular verbs and plurals with plural verbs. The next sentence pattern in complexity is Nominative Nominative Esse. This basically says that you are equating the first thing with the second thing. This pattern is also used to place the qualities of an adjective on a noun. All that really matters is that they are both in the nominative. Make sure they match in gender. : Pater homo est. Amicae mulieres sunt. Magister bonevolus est. Magistra irata est. Nauta bonus est. Manus dextra est. These last two sentence patterns were pretty easy and straight forward, you just have to remember not to put the \"be\" verb in the middle but even if you do it is still correct Latin. It just sounds better to put the verb at the end. The next sentence pattern isn\'t so hard but since we don\'t really have it in English it can throw some. Nominative Dative Esse. This is where you state that a thing is \"for\" a person. \"The book is for him\" and the like. English doesn\'t really have a Dative case anymore so the idea is a bit out there but datives come up all the time in Latin so it is time to start getting used them. : Liber puero est. Mulier homini est. Homo mulieri est. (Nominative dropped) Mihi est. Tibi est. At this point in time it is appropriate to mention the Genitive case. You will notice even though most of your books state that the Genitive case is the possessor case similar to English \"His\" \"Her\" \"Its\" \"Their\", it was not used for that purpose above. In Latin the Genitive case is a quasi-adjective that states an internal quality of the noun. Take a look at the difference. : Puer mulieri est. Puer irae est. I can say \"the boy is for the woman / He is the woman\'s son\" but I can\'t say \"the boy is for anger.\" That makes no sense. But I can say \"He is a boy of anger.\" This gives you the impression that the boy is just angry all the time. *Datives used with the Esse* verb tend to be people, not objects. Genitives used with the esse verb tend to be objects** but can often be people. Here is the difference. : Filius homini est. The very point of this sentence is to tell you that the Son is for the Man. : Filius hominis nauta est. This sentence uses a Genitive because the reason that the sentence exists is not to tell us that the Son is for the Man but that the Son is a Sailor. The fact that he is the Man\'s Son is just an extra idea that we threw on but could easily take off and still have the meaning of the sentence preserved. Filius nauta est. Filius himinis nauta est. Basically, for grammar, we will treat the genitive like an indeclinable adjective. It can go anyplace an adjective can go. The next sentence pattern we will look at is Nominative Adverb est. You basically state a nominative and give extra information about it using an adverb, or a preposition plus case noun. : Petasus illic est. Petasus in mensa est. With Intransitive and Transitive verbs we can use adverbs, prepositional phrases and Ablatives by themselves for this. : Bene video. In via sto. Placido quiesco. This means that you already know another sentence pattern. Nominative Adverb Intransative Verb. Once we jump into the world of transitive verbs you will have a bit more in the sentence to keep track of. A transitive verb allows an Actor (subject nominative) to act (transitive verb) on an object (Accusative). The sentence pattern goes like this: Nominative Accusative Transative Verb. In English we use word order to separate these two because unless we use a pronoun like him, the subject and object of the sentence will look the same. Not in Latin, or at least not often in Latin. In Latin, Subjects sound and thus look different than Objects. Keep in mind that word order could be any order but, so that you can see and get used to what you are seeing, I will stick to Nominative Accusative Verb. In a real Latin sentence, multiple adjective/genitives, adverbs/ablatives and or datives may be in a sentence to extend and enhance the meaning. : Puella puerum videt. See, even with Puer and Puella being next to each other and them being similar in pronunciation, you can still easily determine who is the subject and who is the object. ```{=html} <!-- --> ``` : Pueri puellas cum intentissime observant. No mystery here as to what is going on I hope. ```{=html} <!-- --> ``` : Next we will look at giving verbs. Their sentence pattern goes like this: Nominative Dative Accusative Verb. Nominative gives Accsative to Dative. If you can understand that then this sentence pattern is easy. ```{=html} <!-- --> ``` : Puella puero rosam dat. Puer puellae cephalalgiam dat. Mulier hominibus litteras misit. You will notice I hope that I used the verb Dat twice above. The Dative does indeed take its name from its frequent use with this verb. Also I used the verb Misit. Any verb that means \"give\" \"send\" \"grant\" and the like can logically use this construction. Next we look at Making verbs. This is where you say that you turned one thing into another thing. This can be a noun into another noun or a noun into an adjective. Nominative Accusative Accusative Verb. : Coquus similaginem crustulum fecit. Coquus crustulum dulce fecit. The last of the most basic sentence patterns that you will need to remember and use in everyday speech is Nominative Ab Ablative Passive Verb. In this sentence the Nominative Case is not the actor of the verb but instead receives the action that the verb gives, just like a passive verb in English. Logically, there can be no Accusative in this kind of sentence. The person that is the actor does not have to be stated but if he or she is it will be using the Ablative case after the preposition Ab. : Ab familia mea laudar. Circenses ab omnibus videntur. Those sentence patterns listed above are the most basic and most frequent sentence patterns that you will encounter and have to use is you become a Latin speaker (and you should be trying to become a Latin speaker). These sentence patterns are your base and onto them you will eventually add additional sub patterns that you will use. The important thing is to master these simple patterns first and then move on to more complex structures. Once you know the pattern, it becomes just a matter of vocabulary replacement. Move one word out and put in the desired next word. You should know how to do this through repetition so much that you do not have to think about it to parse or translate. The goal is to understand in Latin and not have to need to translate into English to get it.
# Latin/Words and their Flexion ## Words and their Flexion ### Stem Flexion ------------------------------------------------------------------------ 1\. Words are called in Grammar the Parts of Speech. : Words are either Simple, as flagrare flamma, or Compound as con-flagrare, flamm-i-er : Every Word has meaning and form. Form helps to determine meaning. ```{=html} <!-- --> ``` 2\. Every Word has a STEM and ROOT. : Word and Stem may be (but seldom are) the same, as tu, thou; aqua, water, while Root differs: flamma, flame: Root, flag-, blaze. ```{=html} <!-- --> ``` : Root and stem are often the same: ag-ere, to act. Such words are called Radical or Primitive: all others are derivative. ```{=html} <!-- --> ``` : A Compound Word has only one Stem, but as many Roots as it has composing parts. Thus the Stem of conflagrare is conflagra, the two Roots, cum and flag-. ```{=html} <!-- --> ``` 3\. Every true element in a word following the Root is called a SUFFIX. : Thus in flamma (for flag-ma) --ma is a Suffix; in flagrare, -r, -a and --re and suffixes. ```{=html} <!-- --> ``` : Suffixes may need a connecting Link or Vincular, which is not elemental: reg-I-bus, quer-I-monia. The final Suffix, which converts a Stem into a Word, is called an Ending, as --re in flag-r-a-re. But the Suffix --ma is not called an Ending because flamma is itself a Stem. When it forms flammas, s is an Ending. ```{=html} <!-- --> ``` 4\. A syllable placed before a word to modify its meaning, not being a root word, is called a PREFIX. : Thus in te-tend-I and cin-cinnus, te and cin are Prefixes. But particles in composition, as de-, re-, and se- are not Prefixes as having roots of their own. ```{=html} <!-- --> ``` 5\. The last letter of a Root, as g in flag is called the Root Character. : The last letter of a stem, as a in flamma, is called the Stem Character. The Stem Character, being of chief importance is also known as the Character of the Word. ```{=html} <!-- --> ``` 6\. FLEXION, or Stem Flexion is the method of inflecting a stem, that is, of making such changes in its form to indicate changes in its meaning and uses. : This is usually done by suffixing a Flexional Ending to the Stem: flagra-re; flamma-rum. Such suffixed endings sometimes need a Vincular, as I in regibus; sometimes they cause a mutation of the stem, as flamm-is for flamma-is (which is for flamma-bus). Sometimes change in a letter of the Stem itself is an inflection, such as flamm-a (short a) to flamm-a (long a). Sometimes both Letter-change and Ending are used; ag-, eg-I. Sometimes Prefix, Letter Change and Ending are used: can-, ce-cin-ci. ```{=html} <!-- --> ``` 7\. How then is a Stem defined? : A stem is that part of a Word which is virtually contained in every change of form, though the character is often liable to be hidden through the operation of the laws which determine letter change. So the character of flamma is hidden in the form flammis; the character of virgin- is hidden in the form virgo; the character of dirif- is hidden in the form direxi. ```{=html} <!-- --> ``` 8\. How then is a Root defined? : A Root is the primitive element in any word; that part which the word has in common with all other kindred words. Thus in agito, the Stem is agrita-, but the root is ag-, which it has in common with ag-o, ag-men, and many other kindred words. The Root-character and Root-vowel are more liable to be in hidden through letter change than even the Stem-character. Thus the Root ag- is contained in the words action, examen, redigo, but obscured in word by some mutation.
# Latin/Stylistic Features of Latin Verse and Prose # Stylistic Features of Latin Verse and Prose This is a brief glossary of stylistic features often found in Latin especially in rhetoric and poetry. ## Alliteration Alliteration is a common poetic technique used in Latin from the earliest surviving fragments to the latest literary age. In alliteration there is a repetition of the initial consonantal letter. ### Example 1 Latin English --------------------- ---------------------------- Caesar cum Cicerone Caesar, with Cicero Veni,Vidi,Vici I came, I saw, I conquered bellum bonum good war ## Hyperbaton Hyperbaton is the arranging of words in a particular manner to produce an effect. Hyperbaton is used often in Latin literature because Latin syntax is far more flexible than English. ### Example 2 Latin English ------------------------------------- ------------------------------------------------------------ magnae periculo opes Karthago, \... danger because of great wealth/resources of Carthage, \... Analysis: The word \'periculo\' separates the words \'magnae\' and \'opes\' even if it should be used before magnae opes. ## Hendiadys Hendiadys is a rhetorical and poetic technique that uses the juxtaposition of two or more words with a similar meaning to reinforce an idea. ## Parallelism Parallelism is a stylistic device common in Latin in which two sentences have similar syntax. ### Example 3 Latin English --------------------------- ------------------------ Italia in Europa est. Italy is in Europe. Marcus ad scholam currit. Marcus runs to school. Analysis: In both sentences the nominative is placed first and the principal verb is last. ## Chiasmus Chiasmus is the reverse of parallelism, because syntactic structures are inverted. The name is from the Greek letter Chi which resembles an X and illustrates symmetrical crossing. A good example is the aphorism quod cibus est aliis, aliis est venenum, \"What is food to some, to others is poison.\" The pattern is: noun, verb, pronoun; pronoun, verb, noun. ### Example 4 Latin English ------------------ ------------------- Claudiam laudo. I praise Claudia. Venio ad Marcum. I come to Marcus. ## Litotes The negation of a verb instead of using an antonym is a poetical device known as litotes. Litotes is much weaker than simply using an antonym. Litotes is often used as underestimation. ### Example 5 Latin English ------------------- ------------------------ non ignorare to not be ignorant of As opposed to\... tenere to be knowledgeable of ## Anaphora The rhetorical figure called anaphora is often used in conjunction with parallelism where the first word in the first sentence of a paragraph or stanza is repeated in the following sentences. It is sometimes used where the initial word in a sentence must be understood in the clauses or sentences that follow. ### Example 6 Latin English ------------------------------------------ ---------------------------------------------- timeo ne non pueri essent boni in schola I dread that the boys are not good in school timeo ne non puellae essent bonae domi I dread that the girls are not good at home Analysis: `<i>`{=html}timeo`</i>`{=html} is repeated in the sentence, although not strictly necessary ## Epistrophe An epistrophe is a rhetorical device like anaphora except at the end of a sentence. ## Asyndeton Latin English ---------------- ---------------------------- Veni,vidi,vici I came, I saw, I conquered As you can see, an asyndeton is a multiple numeration without the \"et (and)\" ## Polysyndeton This is a numeration with et: Veni et vidi et vici. Polysyndeton is marked by the repeated use of the same conjunction (et\...et\...et) or (neque\...neque\...neque). It is the direct opposite of asyndeton (listing with no conjunctions). ## Pluralis modestiae This is an advanced technique, often used in ancient fabulae, by Aesop and others. It means that the Plural is used to show \"modestia\", for example \"officium magnum e nostro est.\"
# Applications of ICT in Libraries/Diploma ICTL The Advanced Certificate and the Advanced Diploma in Applications of ICT in Libraries were developed by the Scottish Library and Information Council (SLIC) and are validated by the Scottish Qualifications Authority (SQA) `<big>`{=html}\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--CHANGES TO THE QUALIFICATION\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--`</big>`{=html} The Certificate and Diploma have been superseded by the Professional Development Award in Applications of ICT in Libraries at levels 7 and 8 (English and Welsh levels 4 and 5). They consist of much the same content as the certificate and diploma but the PDAs include two new units: : Digital Culture: Online Communication: In this unit you will focus on the "new literacies" created by digital technologies. You will consider Web 2.0 tools, including social networks, online publishing, online collaboration and virtual worlds. : : Digital Culture: Online Collaboration: This unit considers the sociology and operation of virtual communities. You will discuss the uses of Web 2.0 and online collaboration tools within your workplace. To achieve the level 7 award you must complete three mandatory units: ⋅Locating Information on Behalf of Clients ⋅Using ICT in Library Practice & Professional Development ⋅Supporting Clients in the safe & Legal use of ICT and one of: ⋅Supporting Reader Development ⋅Digital Culture: Online Communication `<big>`{=html}\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--`</big>`{=html} ### What are these qualifications? These qualifications are based on the training already carried out as during the People's Network programme. They have been developed by the Scottish Library and Information Council (SLIC) and are accredited by the Scottish Qualifications Authority (SQA). The level of the qualifications is roughly equivalent to a UK Higher National Certificate or Diploma (HNC/HND), a US Associate Degree or years 1 and 2 of a UK or US undergraduate degree. Credit for approximately one year of study may be transferable to other academic programmes. The Museums, Libraries and Archives Council (MLA), SLIC, CyMAL (the Welsh body) and DCAL (the Northern Ireland department) supported the development of the qualifications for use throughout the UK. SQA is currently exploring accreditation with the QCA (Qualifications & Curriculum Authority) and articulation into higher education. The qualifications have been reviewed by content advisers from across the UK in order to balance any variation in the context of library service delivery and the learning materials contain UK-wide examples of best practice. ### Who are they for? These qualifications are appropriate to library staff in any sector: public libraries, higher education, further education, schools, health libraries, national libraries etc. They are suitable for experienced staff (by showing how ICT can used in traditional library work)and they are also suitable for new entrants to the profession. They may also be of interest to English-speaking library staff in other countries. Candidates would normally be expected to have reached a reasonable level of general education, for example A-Level or SCE Higher and possess reasonable ICT skills, such as PC Passport or ECDL. ### What is the content? The Level 7 in Applications of ICT in Libraries consists of six 8 credit units, each roughly equivalent to 80 hours of study, as follows: Mandatory units: - Locating information on behalf of clients Applications of ICT in Libraries/Locating Information - Using ICT in professional practice Applications of ICT in Libraries/Using ICT in Professional Practice - Supporting clients in the safe and legal use of ICT Applications of ICT in Libraries/Safe and Legal Use of ICT Optional Units (learners undertake one of these units): - Supporting reader development Applications of ICT in Libraries/Supporting Reader Development - Supporting client learning Applications of ICT in Libraries/Supporting Client Learning - Digital Culture: digital communication The Level 8 in Applications of ICT in Libraries includes three 16 credit units (160 hours of study) and one 8 credit unit (80 hours of study): Optional Units (learners undertake one of these units): - Net Navigator Applications of ICT in Libraries/Net Navigator - Educator Applications of ICT in Libraries/Educator (candidates must choose one of these) Mandatory units: - Graded Unit -- Reflective Project Applications of ICT in Libraries/Graded Unit Project - Digital Culture: digital collaboration Summaries of the unit content can be found later in this document. ### What support material is available? A wide range of support material is available, including top-up learning material, assessment tools and electronic log-books to record assignments for authentication in the workplace. The top-up learning material is available in Wikibook format. ### How are they assessed? Almost all of the assessment is of a practical nature and involves the completion of logbooks relating to workplace activities, essays and reports. Most assessments can be submitted online. ### How do they relate to professional qualifications? ### What are the benefits? There are a number of benefits for individual and employers in supporting this development. Staff will have the chance to have their People's Network learning accredited, improve their qualifications, gain academic credits for transfer into other courses or improve their promotion prospects. From the employer\'s perspective, the qualifications will contribute towards workforce development and meeting corporate quality agendas such as Investors in People and Charter Mark. ## Applications of ICT in Libraries: Unit Summaries You can obtain the complete unit specification by following the link after the title. ### Locating information on behalf of clients The purpose of this unit is to guide candidates to work logically through the steps of a reference enquiry, typical for a public library, using Internet resources. 1. Define the precise nature of the enquiry in conjunction with the client. 2. Create a search strategy to fully satisfy the client\'s enquiry. 3. Evaluate the results of the search in terms of validity of information found and its appropriateness in meeting the client\'s needs. ### Supporting reader development The purpose of this unit is to develop skills in public library staff required to use online resources in order to support clients in the development of their reading. 1. Demonstrate an understanding of reader development. 2. Identify, evaluate and use a range of online resources that promote reading to adult clients. 3. Identify, evaluate and use a range of online resources that promote reading to younger clients. 4. Identify, evaluate and use a range of online resources that promote reading to clients with special needs or with specific language requirements. ### Supporting client learning The purpose of this unit is to develop skills in public library staff required to support clients in their selection and use of ICT-based learning packages within the library. 1. Profile client in terms of ICT competence and learning goals. 2. Select a range ICT-based package(s) to support this learning. 3. Provide appropriate ICT support to the client in the use of their chosen learning package(s). ### Using ICT in professional practice The purpose of this unit is to develop skills in public library staff required to use ICT in support of professional practice. 1. Use an automated library management system proficiently. 2. Use and evaluate online selection tools. 3. Use ICT in continuing professional development, to join in professional discussions and to improve own professional practice. ### Supporting clients in the safe and legal use of ICT The purpose of this unit is to develop skills in public library staff required to support clients so that they can use ICT safely for a range of purposes and within the current legislative framework. 1. Demonstrate safe practice relating to the use of ICT for communication. 2. Demonstrate ways in which ICT can support clients with special needs or with specific language requirements. 3. Demonstrate awareness of legislation relating to the use of ICT for storage, manipulation and access of information. 4. Demonstrate awareness of Freedom of Information legislation and information access issues. ### Digital Culture: Online Communication This unit focuses on using social media for communication purposes. It supports developing new digital literacies and using these skills to manage information effectively. 1. Examines communication using social media and collaborative documents 2. Explores using online publishing tools to support library services and continuing professional development 3. Uses new technologies to reflect on the information society ### Carrying Out the Educator Role The purpose of this unit is to develop skills in design and delivery of training on ICT-related topics. 1. Establish ICT training needs for individuals and groups. 2. Select delivery approach which takes account of learner\'s preferred learning style and is appropriate for learning content. 3. Design learning materials and programmes on ICT-related topics. 4. Utilise appropriate skills to support individuals and groups in their use of learning materials and programmes on ICT related topics 5. Evaluate and revise learning materials and programmes on ICT-related topics. ### Integrative Unit (Project) This Integrative Unit is designed to provide evidence that the candidate has integrated the knowledge and skills acquired throughout the programme into his/her ongoing professional practice. 1. Review the programme to identify key areas of learning. 2. Demonstrate the incorporation of key areas into ongoing professional practice. 3. Formulate an approach to continuing professional development in key areas. ## Certification Anyone wishing to be certified for the Diploma or Advanced Diploma must enrol as a student at one of the centres approved by SQA to offer the programmes. Centres may offer the programmes by different means, e.g.: full-time or part time, presencial, distance learning etc.
# Applications of ICT in Libraries/Advanced Diploma ICTL The Advanced Certificate and the Advanced Diploma in Applications of ICT in Libraries were developed by the Scottish Library and Information Council (SLIC) and are validated by the Scottish Qualifications Authority (SQA) \-\-\--CHANGES TO THE QUALIFICATION\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-- The Advanced Diploma has been superseded by the Professional Development Award in Applications of ICT in Libraries at level 8 (English and Welsh level 5). It consist of much the same content as the Advanced Diploma but the PDA includes a new unit: Digital Culture: Online Collaboration: This unit considers the sociology and operation of virtual communities. You will discuss the uses of Web 2.0 and online collaboration tools within your workplace. To achieve the level 8 award you must complete the level 7 award plus two mandatory units: \- Digital Culture: Online Collaboration and - Reflective Practice unit and one of either \- Carrying out the Net Navigator Role or - Carrying out the Educator Role ------------------------------------------------------------------------ ### What are these qualifications? These qualifications are based on the training already carried out as during the People's Network programme. They have been developed by the Scottish Library and Information Council (SLIC) and are accredited by the Scottish Qualifications Authority (SQA). The level of the qualifications is roughly equivalent to a UK Higher National Certificate or Diploma (HNC/HND), a US Associate Degree or years 1 and 2 of a UK or US undergraduate degree. Credit for approximately one year of study may be transferable to other academic programmes. The Museums, Libraries and Archives Council (MLA), SLIC, CyMAL (the Welsh body) and DCAL (the Northern Ireland department) supported the development of the qualifications for use throughout the UK. SQA is currently exploring accreditation with the QCA (Qualifications & Curriculum Authority) and articulation into higher education. The qualifications have been reviewed by content advisers from across the UK in order to balance any variation in the context of library service delivery and the learning materials contain UK-wide examples of best practice. ### Who are they for? These qualifications will permit library staff who have already. undergone the People's Network training to obtain accreditation, but they are also suitable for new entrants to the profession. The main target group is staff working in the UK public library service, but the qualifications are also likely to be of interest to staff in other library services, particularly school libraries. They may also be of interest to English-speaking library staff in other countries. Candidates would normally be expected to have reached a reasonable level of general education, for example A-Level or SCE Higher and possess reasonable ICT skills, such as PC Passport or ECDL. ### What is the content? The Diploma in Applications of ICT in Libraries consists of five single-credit units (each roughly equivalent to 40 hours of study), as follows: - Unit 1: Locating information on behalf of clients Applications of ICT in Libraries/Locating Information - Unit 2: Supporting reader development Applications of ICT in Libraries/Supporting Reader Development - Unit 3: Supporting client learning Applications of ICT in Libraries/Supporting Client Learning - Unit 4: Using ICT in professional practice Applications of ICT in Libraries/Using ICT in Professional Practice - Unit 5: Supporting clients in the safe and legal use of ICT Applications of ICT in Libraries/Safe and Legal Use of ICT The Advanced Diploma in Applications of ICT in Libraries includes all of the above units, plus the following double-credit units, each roughly equivalent to 80 hours of study: - Unit 6: Net Navigator Applications of ICT in Libraries/Net Navigator - Unit 7: Educator Applications of ICT in Libraries/Educator (candidates must choose one of these) - Unit 8: Graded Unit -- Project Applications of ICT in Libraries/Graded Unit Project Summaries of the unit content can be found later in this document. ### What support material is available? A wide range of support material is available, including top-up learning material, assessment tools and electronic log-books to record assignments for authentication in the workplace. The top-up learning material is available in Wikibook format and also in an interactive web-based format at <http://www.ictl.org.uk>. The top-up material includes activities, prompts and refresher learning. More than 600 pages of material have already been written and this is being expanded all the time. The top-up learning can be integrated with People\'s Network, cascade or new training and work-based practice. ### How are they assessed? Almost all of the assessment is of a practical nature and involves the completion of logbooks relating to workplace activities, essays and reports. Most assessments can be submitted online. ### How do they relate to professional qualifications? The qualifications support the CILIP Framework of Qualifications and can be used as evidence towards Certification, Chartership and Revalidation submissions. The Diplomas are based on reflective practice, and electronic logbooks make it easy to build portfolios. ### What are the benefits? There are a number of benefits for individual and employers in supporting this development. Staff will have the chance to have their People's Network learning accredited, improve their qualifications, gain academic credits for transfer into other courses or improve their promotion prospects. From the employer\'s perspective, the qualifications will contribute towards workforce development and meeting corporate quality agendas such as Investors in People and Charter Mark. ## Applications of ICT in Libraries: Unit Summaries You can obtain the complete unit specification by following the link after the title. ### Unit 1: Locating information on behalf of clients The purpose of this unit is to guide candidates to work logically through the steps of a reference enquiry, typical for a public library, using internet resources. 1. Define the precise nature of the enquiry in conjunction with the client. 2. Create a search strategy to fully satisfy the client\'s enquiry. 3. Evaluate the results of the search in terms of validity of information found and its appropriateness in meeting the client\'s needs. ### Unit 2: Supporting reader development The purpose of this unit is to develop skills in public library staff required to use online resources in order to support clients in the development of their reading. 1. Demonstrate an understanding of reader development. 2. Identify, evaluate and use a range of online resources that promote reading to adult clients. 3. Identify, evaluate and use a range of online resources that promote reading to younger clients. 4. Identify, evaluate and use a range of online resources that promote reading to clients with special needs or with specific language requirements. ### Unit 3: Supporting clients learning The purpose of this unit is to develop skills in public library staff required to support clients in their selection and use of ICT-based learning packages within the library. 1. Profile client in terms of ICT competence and learning goals. 2. Select a range ICT-based package(s) to support this learning. 3. Provide appropriate ICT support to the client in the use of their chosen learning package(s). ### Unit 4: Using ICT in professional practice The purpose of this unit is to develop skills in public library staff required to use ICT in support of professional practice. 1. Use an automated library management system proficiently. 2. Use and evaluate online selection tools. 3. Use ICT in continuing professional development, to join in professional discussions and to improve own professional practice. ### Unit 5 Supporting clients in the safe and legal use of ICT The purpose of this unit is to develop skills in public library staff required to support clients so that they can use ICT safely for a range of purposes and within the current legislative framework. 1. Demonstrate safe practice relating to the use of ICT for communication. 2. Demonstrate ways in which ICT can support clients with special needs or with specific language requirements. 3. Demonstrate awareness of legislation relating to the use of ICT for storage, manipulation and access of information. 4. Demonstrate awareness of Freedom of Information legislation and information access issues. ### Unit 6: Carrying Out the Net Navigator Role The purpose of this unit is to guide candidates to work logically through the steps of a complex reference enquiry, typical for a public library, using a complex search strategy, a wide range of internet resources and current awareness and alerting services. 1. Define the detail of a complex enquiry in conjunction with the client. 2. Demonstrate knowledge of search logic, search engines and features of the internet. 3. Create and implement a complex search strategy. 4. Evaluate websites located in a complex search. 5. Review effectiveness of search strategy. 6. Use ICT to set up current awareness and alerting services. ### Unit 7: Carrying Out the Educator Role The purpose of this unit is to develop skills in design and delivery of training on ICT-related topics. 1. Establish ICT training needs for individuals and groups. 2. Select delivery approach which takes account of learner\'s preferred learning style and is appropriate for learning content. 3. Design learning materials and programmes on ICT-related topics. 4. Utilise appropriate skills to support individuals and groups in their use of learning materials and programmes on ICT related topics 5. Evaluate and revise learning materials and programmes on ICT-related topics. ### Unit 8: Integrative Unit (Project) This Integrative Unit is designed to provide evidence that the candidate has integrated the knowledge and skills acquired throughout the programme into his/her ongoing professional practice. 1. Review the programme to identify key areas of learning. 2. Demonstrate the incorporation of key areas into ongoing professional practice. 3. Formulate an approach to continuing professional development in key areas. ### Digital Culture - Online Collaboration This unit examines the creation, sociology and operation of virtual communities and explore how individuals can collaborate for a common purpose using social media and online publishing tools. 1. Initiate and facilitate professional discussions using forums 2. Utilising social media for professional and personal networking 3. Co-orinate a group collaborative social media marketing project 4. Plan, edit and produce a group collaborative blog 5. Reflecting on the most appropriate social media strategy for your information service ## Certification Anyone wishing to be certified for the Diploma or Advanced Diploma must enrol as a student at one of the centres approved by SQA to offer the programmes. Centres may offer the programmes by different means, e.g.: full-time or part time, presencial, distance learning etc. ### Approved Centres At present there is only a single approved centre, but this is expected to change and further centres will be added as approval is granted. #### Millennium City Academy Millennium City Academy is an associate college of London Graduate School of Management, a private college located in the heart of London, UK. It offers the ICTL programmes by distance learning. Full details can be obtained from the college\'s web site <http://www.lgsm.ac>, or by emailing ictl@lgsm.ac.
# Applications of ICT in Libraries/Locating Information This page is designed for the use of students undertaking the Diploma (Diploma ICTL) or the Advanced Diploma (Advanced Diploma ICTL) in Applications of ICT in Libraries. These qualifications were developed by the Scottish Library and Information Council (SLIC) and are validated by the Scottish Qualifications Authority (SQA)\' Locating Information on Behalf of Clients is a core unit in both the Diploma and Advanced Diploma programmes. ## Introduction This unit aims to develop your skills in working logically through the steps of a reference enquiry, typical for a public library, using Internet resources. Reference and enquiry work has always been an integral part of the public library service. Nowadays many queries are answered using electronic rather than print sources. However, the processes and strategies used are the same with both print and electronic searches. So, any experience you have gained in answering queries through printed reference sources will enhance your competence in electronic searches. Enquiry work can provide library staff with a great deal of job satisfaction. No two enquiries, or enquirers, are exactly the same -- so searches for information are varied. Sometimes an information search will present a real intellectual challenge and require you to adopt an innovative or ingenious approach to tackling the enquiry. In such cases getting the required result for the enquirer is doubly rewarding. An effective enquiry service enhances the library's reputation with its clients and creates a positive image for library staff -- as professional, efficient and helpful people. If you are a member of staff in a public library who deals with information enquiries from clients and answers them using the Internet, you will have developed some or all of the expertise required for this unit. Read through the following information carefully. It summarises the knowledge and skills which you need in order to produce evidence of your competence. The unit involves interacting with library clients, establishing their information needs and using the Internet to search for the required information. This must be done in a real library environment and you will need access to the Internet, preferably broadband. Specifically you are asked to: Define the precise nature of the enquiry in conjunction with the client The main knowledge and/or skills required are: - reference interview techniques - open and closed questions - determining the nature of information to be provided-- quantity, level, format - constraints -- deadlines for completion, currency of information and language Create a search strategy to fully satisfy the enquiry The main knowledge and/or skills required are: - choice of search terms - structuring the search - common search engines - directories - meta crawlers - portals - bibliographic databases Evaluate the results of the search in terms of validity of information found and its appropriateness in meeting the client's needs The main knowledge and/or skills required are: - validity of information - reliability, accuracy and currency - measuring success of search in terms of client's requirements -- sufficiency, format and language - structuring and saving of search results for presentation to client, later retrieval, future updating Assessment The unit is assessed through four short searches and one extended search. These will be searches related to typical information needs of public library clients. Some examples are: Short Searches Finding out: - the current community charge rates in your locality - the sequel to a novel which the client has recently read - the post code of a firm for which the client knows name, street and town - whether UK citizens require a visa to visit Thailand Extended Search A client wishes to explore the topic of asylum seekers in Britain. You would produce information giving Government policy, views of other political parties, statistics on immigration etc. ## Defining the precise nature of the enquiry in conjunction with the client ### The Reference Interview Defining the precise nature of the enquiry in conjunction with the client is often referred to as the reference interview. However, you may not carry this out face to face. Instead you may carry out the interview over the telephone or through a series of e-mails. It is undoubtedly easier and quicker though if you can manage to meet the client. There are three main stages here: - Finding out what the client wants to know - Finding out why the client wants the information - Finishing off the reference interview #### Finding out what the client wants to know Before you can answer a question posed by a client, you must find out exactly what that question is. Experienced colleagues will be able to tell you of many situations where there has been a misunderstanding with a reference client, resulting in wasted time and effort and sometimes embarrassment. Whichever means of communication you use, do remember that the reference interview is a two-way interaction or dialogue and you must take responsibility for the efficiency of the communication process. The interview is likely to begin with the client asking you a question. Your task is to probe further until you are fully satisfied that you are clear exactly what the client wishes to find out. Remember to ask for clarification from the client about the topic, e.g. ask them to spell uncommon words, expand on the topic under investigation etc. #### Finding out why the client wants the information It is extremely helpful if you can establish early on in the interaction the reason why the client wishes the information requested. Tact may be required here, however, as some clients may be unwilling to give this information. This is especially likely where the enquiry is of a sensitive or confidential nature, such as a medical or financial problem. If the client appears uncomfortable or evasive when asked why the information is being sought, then it is unwise to probe further. You should ascertain the starting point of the enquiry in order to avoid time being wasted on finding information which the client already knows. Ask whether the client has already undertaken any research on the topic and what the results of this were. This can give guidance on successful and unsuccessful information searching approaches. But do not write off a particular approach just because a client assures you that it has yielded no information. Remember the client is not an information specialist -- you are! -- and so the client may not have searched as thoroughly or as efficiently as you would. #### Finishing off the reference interview By the end of the reference interview you should be confident that the nature of the enquiry has been fully explored and that the information required by the client has been specifically defined. The reference interview also provides the opportunity to establish any special needs of the client e.g.: visual or auditory impairment. And finally, do remember to record contact details for the client. In the excitement of exploring the enquiry and establishing the client's precise needs, it is all too easy to forget this important information. So make sure that every reference interview ends by your recording name, address, telephone, fax, e-mail details, as appropriate. If you will be phoning the client, it is also polite to note when it is convenient for the client to receive your call. YouTube How not to conduct the reference interview 1 Auckland City Libraries The reference interview 2 ### Spoken and written communication Good communication skills are key to the reference interview. This topic provides a good opportunity for practising and refining your communication skills. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, list the key factors you think would lead to good communication in a reference interview. Write these down on a piece of paper. ------------------------------------------------------------------------ #### Factors leading to good communication We think the important factors are: - Appropriate spoken language - Appropriate body language - Good feedback especially on the telephone - Good note taking skills - Clear and grammatical e-mails #### Spoken language You should use language which is appropriate to the client, avoiding talking down to the client or, at the other extreme, baffling the client with specialist jargon. If you do have to use a term which the client may not understand, e.g. "bibliography", be sure to explain it. For example, how would you explain "search engine" to a client who is not familiar with this term? You might say something like "A search engine allows you to search for websites related to a particular topic. To use a search engine, you have to choose and type in appropriate key words describing the topic #### Body language In face-to-face situations, use appropriate body language designed to set the client at ease and promote effective communication. Smile and greet the client by name if possible. Lean forward slightly and use eye contact to show your interest in the conversation. Try to carry out the interview in a place where both you and the client are sitting comfortably and at the same level, preferably side by side. What would you deduce from the body language of a client who fidgeted during the reference interview? The most likely explanations are that the client: - is in a hurry, perhaps because of another appointment - may feel nervous in the library environment or about asking for your assistance with their query. Test your understanding of body language with this simple quiz - <http://www.kent.ac.uk/careers/interviews/nvc.htm> #### Feedback With telephone communications you will have to be careful in order to make sure that you fully understand what the client says because you will get no clues from their body language. You should use appropriate feedback techniques to ensure understanding of the client's responses. For instance, you might: - Rephrase what the client has said and repeat this back to them - Ask if you can read out a summary of the enquiry based on the notes you have made. See if you can pick up clues from the tone of the client's voice. Conversely, make sure that your tone is positive and encouraging. Smiling as you speak into the phone generates a pleasant tone of voice which encourages helpful responses. #### Note taking In both face to face and telephone interactions, it is essential to take written notes of the main points of the conversation. These notes are your reference for checking that you have fully understood the details of the client's enquiry. You may have to put the query on one side for actioning later or you may pass it on to a colleague to deal with. In both cases a written record will be essential. #### Writing e-mails If you are using e-mail to communicate with the client, it is important to establish a cordial tone while remaining concise and to the point. Writing clearly and grammatically is key to this, as is structuring your e-mail so that the client can follow it easily and respond appropriately. The correct sequence for actioning an e-mail enquiry is as follows: 1. Thank the client for the enquiry 2. Summarise what the enquiry consists of 3. Give your proposals for how you will action the enquiry 4. State when you will provide the search results 5. Request confirmation from the client that your proposed actions and timescale are acceptable ### Open and Closed Questions In the reference interview, you will use both open and closed questions. These have different uses. It is important to be able to distinguish between the two types of question and to use them appropriately. Closed questions prompt yes/no or short factual answers, such as: Q. What time did you come to the library? A. 9 o'clock Q. Is your daughter called Amelia Austin? A. Yes Closed questions are mainly used in the reference interview context to: - elicit specific pieces of information from the client - gain confirmation that the your understanding of what the client has said is correct - an important feedback tool The following are examples of closed questions: Do you use a left-handed mouse? This is a closed question which will be answered by yes or no. What is the charge for printing a page of A4 text? This is a closed question which will be answered by a specific sum of money such as 10p. Open questions encourage longer answers, such as: Q. Why did you ask for a dictionary? A. I wanted to check whether there was a difference in meaning between "main" and "mane". The main uses of open questions in the reference interview context are to: - establish rapport with the client - set the scene for the enquiry - gain background information which is relevant to the enquiry The following are examples of open questions: What will your students be using this information for? A typical reply might be: \"These are students undertaking an initial course in professional cookery. They will need the data to understand the calorific content of the foods in the recipe." Can you tell me how you went about looking for this information? A typical reply might be: \"I started off looking up autism in the encyclopedias but the information was too general and not up to date enough. You will use both open and closed questions at appropriate times. When framing a question, always think of the type of response you hope to generate and word the question so as to encourage either a brief or an extended answer. ### Nature of information required Apart from the actual topic of investigation, there are other factors which need to be taken into account before a member of library staff will embark on the information search. There are three main factors: - the quantity of information required - the level of information required - the format of information required #### Quantity What appears to be the same request for information could produce results differing in quantity by orders of magnitude. You must clarify the scale of information required by the client in order to fully satisfy their needs. It may be that reference to a single book or website is required. Alternatively many in-depth sources of information may be required so that the client can analyse a breadth of opinion on the search subject. Providing too much information is just as unhelpful as providing too little. #### Level It is essential that the information provided is at a level of complexity which enables the client's full comprehension but does not patronise the client or tell them what they already know. The following points are a good guide: - the client's age (but remember age does not automatically bring wisdom!) - the client's educational attainment - the client's display of specialist knowledge - the client's linguistic ability - whether the information is intended for the client themselves or for use by other people. Tactful questioning can be used to make an estimation of the points listed above. #### Format The results may include information in various formats. Difficulties may arise if the client has expressed an initial preference for a format in which the information is not actually available. If the information is only available in a limited number of formats, you must alert the client to this and ascertain if any of these formats are acceptable. If the search is not carried out with the client present, you must ascertain if the client can visit the library at a later time to access the search results or if the information must be in a format which can be e-mailed or posted to the client. There are many formats available, including several as a result of the introduction of ICT. Your search may direct the client to items of library stock, to be used in the library or borrowed for home use. This could include: - Printed reference sources or information CD-ROMs - Books, audio or video material for home borrowing - Magazines and journals - Pamphlets or leaflets The search results may be bibliographies or lists of website references for the client to follow up. The results may be viewed on screen by client, in the form of text, audio or video. ## Create a search strategy to fully satisfy the client's enquiry ### Choosing search terms Searching for information using the most appropriate key words is important in any reference enquiry. But it is arguably even more important in an Internet search than when you are looking through printed indexes. When carrying out a manual search, the human mind can make links and jump from one search term to another. Computers on the other hand stick strictly to the script and will only find information which matches what you have instructed them to look for. Let's look at how you can derive the search terms for an enquiry. You must be able to analyse a topic and break it down into its component parts. At its simplest you just extract the significant words, usually the nouns and verbs, and use these as search terms. An example would be a client asking for information about "How would you cook a vegetable like fennel?" Which word(s) would you choose as search term(s) in this enquiry? The best choice would be \"cook\" and \"fennel\" - these two words are the essence of the enquiry. \"How would you\" is too general and \"vegetable\" would only be needed if there was some ambiguity over the nature of fennel. The above is not necessarily true depending on the search tool you are using. For example if you use YouTube and type in - how do you\... for almost any subject you will find video showing exactly what you want to know. #### Examples of search terms Here are some further examples of enquiries where you would be able to use one or more words from the client's initial question as search terms. The search terms are in bold. I need some advice on keeping a greyhound as a pet. What are the symptoms of diabetes? Who is the chief executive of CILIP (the Chartered Institute of Library and Information Professionals)? What colour is the flower commonly known as ragwort? Of course, the question as posed by the enquirer may not contain words which are the best search terms. You may need to think of alternatives in the form of synonyms (words which mean the same) and words related to the terminology used by the client. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.1 List some reasons why synonyms and related words might be better search terms. ------------------------------------------------------------------------ #### Synonyms It is important to consider synonyms of a search term because the word given to you by the client may be one of many which describes the concept to be searched for, e.g. if a client wishes to know about illness, it may be useful to carry out a search with the word disease instead. Try this example for yourself. Carry out two searches using the same search engine, the first with sports competitor as your search term and the second using sports opponent and look at the differences in the results. The term suggested by the client may be a less commonly used or out of date expression, so it is vital to think of more usual or appropriate synonyms. The client might ask about Ceylon when requiring information about the country now known as Sri Lanka. It would therefore be appropriate to search under both Ceylon and Sri Lanka. If you have time test your knowledge of the English language here - <http://www.kent.ac.uk/careers/tests/synonyms.htm> #### Related terms Sometimes it is useful to use a related term for the word given by the client. When a client asks for information on malnutrition in Africa, a related term could be used instead of the rather broad one. An individual country could be substituted, such as Sudan. Of course, you must take into account that using related terms can change the nature of your search. In this example, using Sudan will give you results which are influenced by the particular problems suffered by this country which differ from other parts of the continent. Can you come up with one or more potentially useful related terms in searching for each of the following? - web 2.0 applications in a library context - genetically modified crops - popular music in the 1960's - saving using insurance policies - capital punishment in the USA Some examples are: For web 2.0 applications you could use social media For genetically modified crops: Frankenstein seeds, Monsanto, soya For popular music in the 1960's: the name of any singer or group from this era -- the Beatles, Dusty Springfield For capital punishment in the USA: death row, electric chair, gas chamber, names of individual states where capital punishment is used e.g. Texas Another aspect to be considered when choosing search terms is that while the client may give you descriptive terms for the information required, it may be more effective to search on actual names of individuals or organisations or concepts. Taking the earlier search regarding malnutrition in Africa, the description malnutrition could lead you to search using the key words World Health Organisation. This will lead to the WHO site where information on diseases in specific African countries is quickly located. Can you come up with a name of an organisation or individual which could be a useful specific term in searching for each of the following? horse racing the royal family relativity theory college courses There are many related terms which apply to each of these. Here are the examples which we thought of: Shergar, British Horse Racing Board The name of any member of the royal family, such as the Prince of Wales Albert Einstein The name of your local college Note that the previous three techniques depend both on your ability to interpret the client's description and on your own general knowledge. With experience and in discussion with knowledgeable colleagues, your skills will increase. #### Ambiguity You should also keep in mind that some words are ambiguous. China can mean a country in the Far East or pottery products. The English language is particularly rich in such ambiguities. In the reference interview you will have clarified the meaning of any such ambiguous words. Now at the search stage, you should either use a non-ambiguous synonym (if one exists) or add an additional search term to remove the ambiguity. Some simple examples are: Cycle -- is it the bicycle or a rotation? Yarn -- could mean thread or a tall story. Kids -- could lead to children or young goats. ### Structuring an Internet search As an information professional, you need to know all the shortcuts to information that client's request. This means more than just typing search terms into Google! Structuring the search involves the choice of different search engines, metacrawlers, directories and portals or, where you are already familiar with appropriate websites and their content, direct interrogation of these. In order to search effectively on the Internet, you need to be familiar with the different types of websites used to search for information. Three general types are the search engine, the metacrawler and the directory. Each operates and is used in a different way, although several sites incorporate more than one type. For example the Google site consists of both a search engine and a directory. #### Search Engines A search engine is a website that allows you to input words representing your search terms and uses these to come up with a list of websites which should be relevant to your search. Repeating the same search using different search engines may lead to different results due to the way in which the various search engines search the web and order the sites found. You should have experience of a selection of search engines to understand their similarities and differences. It can be illustrative to make identical searches on a number of search engines and observe the different results. There are many different search engine sites. It is important to have a grasp of a few of the most important sites, i.e.: those that lead quickly to useful information. This can be because they specialise in a particular sector are well funded and thus comprehensive. (Such sites are popular and so command large fees for their advertising services.) ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.2 Start by familiarising yourself with some of the popular search engines which will be important in your information searching. Go to each search engine listed below and try out the search term British planes. Do not bother to use capital letters in the search terms as the search engines do not really take them into account. Note down what you find in the layout and types of information displayed. ------------------------------------------------------------------------ You will find four rather different results. Even if the same results were displayed (which is unlikely given the slightly vague search term), each search engine presents the information in a different manner. #### Differences between search engines Google and Yahoo are somewhat similar with a simple list but Google presents Wikipedia pages and news near the top. Ask Jeeves starts off with a list of commercial sites, all wanting to do business with you and only lower down shows you 'real' results. But in its favour, there is a list of related searches down the right hand side. Clusty is at first similar with a list of results and a few advertisements but there is a very useful feature in that down the left hand side, it clusters the results in categories which it has discerned. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.3 Try Clusty out with the search term organ and you will see the value of the category feature. Because organ is ambiguous as a search term, Clusty very neatly categorises its results into organ as a musical instrument and parts of the body. You can see that in this way Clusty can lead you to a set of results more focused that the other three search engines. ------------------------------------------------------------------------ Of course none of these search engines is perfect and it would unwise to rank one above another. #### Compound queries Note that our search terms consisted of two words, British and planes. When you look down the results at all four websites, you will see that only sometimes are the two words adjacent and that some of the results only have one of the words present. Most search engines have the convention that to indicate the compound term the words should be in quotes i.e.: "British planes". ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.4 Try this out with Jersey cows. Enter the two words with and without quotes and compare your results. ------------------------------------------------------------------------ Try to get as much experience as you can in using different search engines. You will learn that although using only Google, say, will give you lots of results, the use of a few different engines may give you a better overview of the range of information available for any chosen search topic. #### How search engines work It is helpful to know a little about how search engines work. In simple terms, they search the Internet and look at the websites and their contents. They index the information they find on the site and in the metadata descriptions placed on each site by its creator. This information is used to lead from your search terms to the results. Of course each search engine uses its own particular methods. You can find out more about this either by doing a search or looking for information on the actual search engines. This matching does have its pitfalls and if using ambiguous search terms you may get at best many useless results and at worst offensive ones. #### Metacrawlers Based on the maxim that more is better, Metacrawlers apply your search terms to several search engines simultaneously. Metacrawlers come in many forms and are sometimes described as meta search engines. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.4 Familiarise yourself with some of the popular metacrawlers which you can use in your information searching: Go to each metacrawler listed below and try out the search term British planes. - Dogpile at <http://www.dogpile.co.uk/> - Surfwax at <http://www.surfwax.com/> - Mamma at <http://www.mamma.com/> - Ixquick at <http://www.ixquick.com/eng/> Note down what you find in the layout and types of information displayed. ------------------------------------------------------------------------ Again there are different results and some very different layouts. One major reason for using metacrawlers rather than individual search engines is that you hope to get a good spread of the best information. We would suggest that this works best early in a search to get and idea of the breadth of the information available. Using a metacrawler also saves you having to visit each of the individual search engines. #### Web directories Unlike search engines, web directories do not search for you but are arranged as an alphabetically ordered index to the web, developing into a tree structure of levels of sub-categories. This is somewhat similar to the subject index in a print encyclopedia. Directories can be very useful in allowing you to home in on the general area of a reference search. However there are countless directory sites, many of which are poorly maintained. Poor maintenance manifests itself with broken links or links to inappropriate material. You should make yourself familiar with the good examples of directories and we will examine some of these now. General purpose directory sites are provided by many search engines: Google and Yahoo are examples. Most confusingly they show both the categories which you can descend and a search facility which looks like the web search but is in fact used to search the categories. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.5 Examine some of the general purpose web directories which you can use in your information searching: Go to each directory listed below and try to look for information on flower arranging: - Yahoo at <http://dir.yahoo.com/> - Open directory at <http://dmoz.org/> ------------------------------------------------------------------------ #### Differences between directories and search engines One key difference between the directory and the search engine is that the entries in the directory should be compiled 'by hand' and not through automated searching. This may be seen as an advantage if you consider that a human is better at categorising the sites i.e. spurious sites may be eliminated. We feel that the really useful directories are the more focused relating to environmental information. You can also appreciate that browsing through the tree structure of the directory can be time-consuming and will not automatically lead to a result. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.6 There is a tremendous amount of information available at <http://searchenginewatch.com/> covering every conceivable aspect of information providing websites. Have a look at this website for further tips. ------------------------------------------------------------------------ An alternative approach is the use of Portals. #### Using portals A portal is, at its most general, a website which offers grouped links leading to information. General purpose portals, such as www.msn.co.uk or www.yahoo.com, are often used as home pages by users and have links to life style sites. These sorts of general portals are rarely of use in answering information enquiries. Some more specialised portals are tailored to be used say, to provide a child friendly web experience (e.g.: <http://home.disney.co.uk/>), as they give relative safety from inappropriate material. Other specialised portals focus on particular topic areas and it is these which can save you time in answering reference enquiries. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.7 Familiarise yourself with some of the portals which you can use in your information searching. Go to each portal listed below and get a feel for the information you could access through it. - DirectGov at <http://www.direct.gov.uk/Homepage/fs/en> - Wine.Com at <http://www.wine.com/> - Visit Scotland at <http://www.visitscotland.com/> - Irish Abroad at <http://www.irishabroad.com/> - Connects at <http://www.connects.org.uk/> ------------------------------------------------------------------------ There are thousands of portals. With experience you will get to know a number of useful ones for sourcing specific information. #### Using bibliographic databases Bibliographic databases permit the retrieval of information in a variety of formats and media. Some of these are commercial subscription services, e.g.: www.booksinprint.com. You must be aware which databases your library subscribes to. If you do not know this already, check it out now. Other bibliographic databases which are free of charge include the catalogues of major libraries -- such as the British Library's catalogues containing over 12 million books, serials, printed music and maps. University libraries usually have online catalogue access, as do public libraries. Booksellers' databases can also be useful sources of online bibliographic information. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.8 Familiarise yourself with some of the bibliographic databases which you might use in your information searching: Go to each site listed below and get a feel for the information you could access through it. - British Library at <http://www.bl.uk/> - Cardiff University Library at <http://library.cf.ac.uk/> - Blackwell's at <http://www.blackwell.co.uk/> ------------------------------------------------------------------------ ### Frequently-used websites It is useful to acquaint yourself with sites of major organisations which hold information relating to commonly asked enquiries. Examples are government departments, your own local authority, major voluntary organisations and organisations of local interest. \-\-\-- ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.9 Familiarise yourself with some websites which will be important sources of information for you: Locate the Government's Home Office website and find the telephone number for General Enquiries Locate the website for your local authority and find a list of the local councillors Locate the website for the UK Citizens Advice Bureau and find the location of your local bureau. Locate the website for your nearest airport and find a list of destinations flown to. Now expand on this by thinking of other likely sources of specialised information and check out these websites for yourself. ------------------------------------------------------------------------ #### Internal searches As well as using search terms in search engines, you should notice that you can conduct a search within a website using the internal search facility provided by the site. A good example is the search facility within www.scottish.parliament.uk which permits searching by subject terms within specific areas of the site and for specified types of documents. This site has both simple and advanced search facilities. Use the Advanced Search facility to find debates in the chamber which relate to apprenticeships. ### Website suffixes When you are looking at websites, it is useful have an understanding of implications of the common suffixes used in the addresses for websites (called URLs). Some suffixes give a clue about the nature of the organisation which owns the website. Note, however, that for some suffixes there is no absolute fixed rule for their use. Thus you would find that gov.uk always indicates a local or national government site in the UK. By contrast, although .org suggests a non profit-making organisation, there is no guarantee that this applies to every .org website. Here is a list of common organisational suffixes and their meanings. - .ac Academic - .biz Business - .co Commercial - .com Commercial - .edu Educational - .gov Local or National Government - .int International - .net Network - .org Non profit making #### Geographical suffixes There are also geographical suffixes with .uk for the United Kingdom and .ie for the Republic of Ireland. The United States is the only country which does not use a suffix. The .us suffix exists, but is seldom seen. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.10 Go to <https://www.norid.no/en/om-domenenavn/domreg/> or another similar site and find the suffixes for Internet sites for the following countries: - Australia - Canada - France - Germany - India - Pakistan ------------------------------------------------------------------------ ## 1.3 Evaluate the results of the search ### Validity of information Information found on the Internet can sometimes be problematic. It is always important for the information professional to validate information found during a search, whether this results from printed or electronic sources. However, the information found in reference books and other printed materials in public libraries has usually undergone a rigorous selection process. Thus some of the validation of information has already taken place through the selection process. This is not the case with Internet sites. Individuals or organisations can, at almost negligible cost, upload information to websites which are then accessible throughout the World. Such sites may present information which is out of date, biased to one point of view or just plainly wrong. So all information found on the Internet must be critically evaluated. This is an important role for the information professional. Non-specialists are less likely to query the information found on the Internet -- perhaps they assume that it has been vetted in some way, just like the reference books in our libraries. There are three main criteria for validating information: reliability, accuracy and currency. #### Reliability There are a number of criteria which can be used to give you confidence in the reliability of the information on a website. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, list what you think are the criteria for establishing the reliability of a website. ------------------------------------------------------------------------ #### Reliability criteria We think that the following three points are very important: - the expertise and reputation of those connected with the website - evidence of lack of bias - evidence of equal emphasis towards all aspects of the search topic #### Expertise and reputation If you can see that the website is supported by a reputable organisation or contributed to by a person with known expertise then it is reasonable to accept the website as being reliable. Examples would be where a website giving medical advice was run by a government department or a well respected charity e.g. NHS direct at <http://www.nhsdirect.nhs.uk/> or Cancer Research UK at <http://www.cancerresearchuk.org/> Another more trivial example is that you would expect to find reliable recipes at Delia Smith's website <http://www.deliaonline.com/> #### Lack of bias Individuals can be biased in their opinions. Even well known experts may represent only one aspect of a topic. Many websites by their very nature present information from only one viewpoint and are thus biased. While such information need not necessarily be excluded from the results presented to the client, you must indicate any identified bias and, if possible, provide information from other sources which present opposing points of view. This is particularly important when the client is seeking information on potentially contentious matters such as politics, religion, race or issues related to pressure groups. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.1 As an exercise in looking for bias in websites, search for a pair of websites giving opposing points of view on the following topics. - keeping a monkey as a house pet - the need for the UK Monarchy - the greenness of nuclear fuel - the usefulness of homeopathy ------------------------------------------------------------------------ #### Opposing views The following example sites were available at the time of the latest review of this section. - Opposing views on keeping a monkey as a house pet can be found at Pet Assure <https://www.petassure.com/maxscorner/can-monkeys-make-good-pets/> and at <http://www.aspca.org/adopt/adoption-tips/exotic-animals-pets> the website of American Society for the Prevention of Cruelty to Animals. - Opposing views on the need for the UK Monarchy can be found at the official UK Monarchy site at <http://www.royal.gov.uk> and a Marxist perspective at <http://www.marxist.org.uk/> - Opposing views on the greenness of nuclear fuel can be found at the Greenpeace website <http://www.greenpeace.org.uk/> and that of the World Nuclear Association <http://www.world-nuclear.org/> - Opposing views on the usefulness of homeopathy at the site of the British Homeopathic Association at <http://www.trusthomeopathy.org/> and the National Council Against Health Fraud (NCAHF) Position Paper on Homeopathy found at <http://www.ncahf.org/pp/homeop.html> Although the exercise and the results may seem a little trivial, it is useful. The problem when you are faced with queries about these sort of contentious issues is that you will initially retrieve a site as a result of your information search which gives only one side of the case. You must then search for the opposite, just as you have done here. #### Equal emphasis Emphasis differs from bias in that it is omission of information rather than deliberate over-statement of one point of view. For example, US sites may devote little space to British developments. Another pertinent example in UK public libraries is that sites for UK government departments may include information only for England on devolved issues. You should be aware that emphasis can be more difficult to detect than bias. A solution is to apply the technique of cross checking with other sites on the same topic. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.2 Look at the government website for the Department for Education <https://www.gov.uk/government/organisations/department-for-education> . Education is a devolved responsibility and thus varies considerably between the four UK nations. Much of the information on the DfES website applies only to England and sometimes Wales. Compare the information about literacy strategy in schools with that given on: - <http://www.deni.gov.uk> Department of Education Northern Ireland - <http://www.scotland.gov.uk/topics/education> Scottish Government Education and Training - <http://www.learning.wales.gov.uk> Welsh Assembly Government Education and Skills ------------------------------------------------------------------------ #### Accuracy When you are looking for factual information you can usually assume that a reliable site based on the points above will attempt to provide correct data. However, mistakes can be made and you should cross check data using more than one reliable site wherever possible. #### Currency In using the Internet you often come across websites which are seriously out of date. In fact some of them are actually abandoned and will never be updated again. When you use websites in your information searching, you must make sure that the information is current. Of course with a reference book you can look at the publication date. However for websites it is not just so easy. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, list some points you could look for on a website to establish its currency. ------------------------------------------------------------------------ #### Establishing currency We can think of a few possible ways of establishing the currency of a website. Obviously they depend on finding date information. This can be explicit: - You can check the "Last revised" date on a website. This is usually found on the first screen. Note that this may only indicate the last time a change was made to a particular part of the website and that it does not imply that all the content was updated on that date. - You can look to see how recent are the publication dates of the documents referred to on the site - You can look out for dates quoted within text and make an estimate of currency - You might find a "Forthcoming events" list where all dates should be in the future, or in the very recent past. In the absence of any explicit date information you may need to look at Indirect methods of establishing currency #### Indirect methods of establishing currency If there are no actual dates mentioned, you will need to look for more subtle indications that the site is regularly updated. - You can look for regulations or laws mentioned in the site and find their dates of introduction. - You can look for the names of institutions or Government departments. These do change name and can be used to give a date range. - You can look for the names of personalities involved in the topic which can show currency. - Finally you can simply look for reference to recent news items which will date the site's information. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.3 Look at <http://www.bbc.co.uk/comedy/littlebritain/> This is a reputable site and it clearly states whether the site has been recently updated. ------------------------------------------------------------------------ ### Measuring the success of a search At the start of the enquiry process, during the reference interview you should have determined clearly the client's requirements. At the end of the enquiry process you must review the results of the search against these requirements in order to check that the search has been fully successful. In some cases you may not be able to fully satisfy the client's requirements. If this happens, the reasons for this must be explained to the client e.g.: information does not exist in the format specified. You should propose some alternatives if these are possible. There are three main criteria, sufficiency, format and language. #### Sufficiency Is there enough information or too much? If it is a straightforward fact being sought then you should have no difficulty here. However for a more complex search you must make sure that you have not overdone the amount of data retrieved to prevent swamping the client and if necessary trim it a bit. Conversely you must check that you have supplied enough information. If the client suggests that more would be appreciated, you can indicate tactfully that you have provided what was asked for but offer to search further if required. #### Format Make sure that the client's requests for particular formats, such as text, print-out, e-mailed results, audio or video have been met with. #### Language You should make sure that the client's requests for information in a particular language have been followed. ### Structuring and saving of search results The raw data should be presented in a structured way which facilitates understanding by the client. In particular, it is important for the client to be informed of the source(s) of the information found. For simple searches, the result is likely just to be a short statement of fact. Here all that is required is that the information is presented clearly and unambiguously. However simple the information, we do recommended that it is given to the client in writing and that you keep a copy. That way there can be no argument later about the results. And having a written record means that the client does not have to depend on their memory to recall the information. For searches which result in a considerable amount of information, you should present the results in some sort of logical order. Different orders suit different types of enquiry. #### Ordering results You might adopt one or a combination of: - Following the progress of the search -- "First I looked at the Food Standards Agency site and this told me....., then I moved on to the Association of Farmers Markets where I found.... etc. - Geographical order -- grouping information from a country together - Chronological order -- to show how a topic developed - Alphabetical order -- if the result of the search is a list of references - By point of view -- information on one side of the argument, then the opposing side. These are only some possibilities and you should not feel compelled to choose one of these. The important thing is that your structure for presenting the information suits the topic and is helpful to the client. #### Bibliographic references If the results of your search include bibliographic references, these should be quoted in a consistent and accepted style. You can find advice on this on the websites of most universities. A good example is Anglia Ruskin University <http://libweb.anglia.ac.uk/referencing/harvard.htm> or you could try the University of Warwick at <http://www2.warwick.ac.uk/services/library/main/help/guidespublications/bib_cit/> It is important to realise that your search and its results represent useful work, which does not simply end when the results are handed over to the client. We can think of two straightforward cases where reference will be made to your work in the future. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding write down two possible reasons for archiving searches for future use. ------------------------------------------------------------------------ #### Archiving searches Ignoring the possibility that the first client loses the data and wants another copy of it (this can happen!), the most likely scenario is that another client comes into the library and asks the very same query. Here, if you have stored the enquiry information properly, you can simply go to the search and produce a copy of the results. In this case, the search results should be archived in such a way that the search can be retrieved by appropriate key terms. These will be subject key words. Ideally the library should have a formal system for recording the results of frequently asked questions. You should be aware if your library service does this and, if so, make sure that you know how to add your information search results to this. #### Frequently asked questions One good example of a library database of frequently asked questions is Edinburgh University's "Previously AnsweRed Questions -- PARQs". ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.4 Examine Edinburgh University's "Previously AnsweRed Questions -- PARQs" site on <http://www.lib.ed.ac.uk/faqs/parqs.shtml> and find the answer to the question "How much did the Forth Bridge cost?" ------------------------------------------------------------------------ We think you will agree that this facility is very easy to use. Note how, in addition to answering the questions, the site points the enquirer to further sources of information by means of hyperlinks. If your library service does not have a formal service-wide system like this, you should consider setting up a simple version for yourself and colleagues at your service point. This is relatively simple to do using a database package available in your library. #### Updating data Another situation where you may wish to revisit your search is where the same client reappears and wants you to repeat the enquiry at a later point in order to update the data or include new developments which have taken place since the original search was undertaken. In this case it is important to save not just the search results but also the search strategy. You will need to repeat the strategy in order to update the information found the first time. You may find that certain enquiries have a habit of repeating at the same time each year. An example would be where pupils always undertake a school project on a particular topic at the beginning of each academic year. You know that every September a group of 12 year olds will descend on your library desperately seeking information on young people and drugs in the locality. In this case, you can even prepare yourself in advance by repeating your search before the question is posed, so that you are prepared to assist the young people with their information needs.
# Applications of ICT in Libraries/Supporting Reader Development This page is designed for the use of students undertaking the Level 7 PDA (previously called Diploma) in Applications of ICT in Libraries. This qualification was developed by the Scottish Library and Information Council (SLIC) and are validated by the Scottish Qualifications Authority (SQA) Supporting Reader Development is an optional unit in the programme. Information regarding the background to the courses, content and certification opportunities can be obtained by following the old (Diploma ICTL) or Level 8 PDA (Advanced Diploma ICTL) links. Further information can be obtained from angela.lees@sqa.org.uk # Objectives of reader development In recent years libraries have moved towards fostering reader development, a more reader-centred approach. A good definition of reader development is: \'\'\'active intervention to: - increase people's confidence and enjoyment of reading - open up reading choices - offer opportunities for people to share their reading experience - raise the status of reading as a creative activity\'\'\' (See <http://www.openingthebook.com/reader-centred-library>) Add alternative definitions below. # Reader development techniques Reader development is not about reading "better" books, in the sense that these are more worthy literary titles - the objective is that the reader relishes the reading experience and reads the books with a sense of satisfaction. Reader development can involve: - reading promotions - use of genres - literacy initiatives - reader centred selection skills ## Reading promotion It is important at the outset to distinguish between reading promotion and reader development. A reading promotion aims to market a small number of titles while reader development sells the whole reading experience and what it can do for you, rather than promoting individual books or writers. That said, however, reading promotions can still play an important role as part of a wider reader development programme, as they can alert readers to titles which they might otherwise remain unaware of. Reading promotions may be local (within the library or local authority library service), national or even international. Reading promotions focus on small or moderate numbers of book titles which are grouped together and marketed as a list or reading pathway for the client group. This group might be adults, younger clients or clients with special needs or specific language requirements. Sometimes, language, subject or publisher links them together. Although reading promotions are not reader-centred (their objective is to increase sales or issues), they do bring books to the attention of readers and may attract new readers because of their display and supporting print materials. Grouping books together in a promotion centres the reader's attention on them and will lead to increased client use of this stock. Activity: Find some examples of recent book promotions in which your library service has participated. Discuss with colleagues what was successful or unsuccessful about these promotions. ## Current book promotions There are so many book promotions that we could not attempt to give a comprehensive listing. However, here are three examples of current book promotions which could be applicable to public libraries, together with our comments on these. Maybe some of them were included in your list. ### Richard and Judy's Summer Reads <http://www.richardandjudybookclub.co.uk/> Celebrities Richard and Judy promote reading through their Summer Reads and Book Club. Whilst this is a small range of titles, these titles receive a high profile in the media and outlets like supermarkets, bookshops, stations and airports. It is always important to be aware of what is in the media spotlight, as requests from clients will follow. Richard and Judy's titles are contemporary paperback fiction. ### Welsh Book Council <http://www.cllc.org.uk/hafan-home> This website promotes access to books by Welsh publishers and contains useful reading suggestions for readers. It is important that local/national authors and publishers are promoted to encourage and sustain the growth and development of the local/national cultural industry. In addition Welsh/Gaelic language material should be made available to meet the needs of readers. ### Mills and Boon <http://www.millsandboon.co.uk> Mills and Boon publishers are well known for their range of romantic fiction. Their website includes a large number of titles but it will only appeal to a limited group of readers and has a commercial rather than reader-centred objective. # Genre A genre is a "family" group of books which share style, form, or content, e.g.: crime fiction. Activity: List other fiction genres which are common in public libraries. ## Fiction genres When you look round any bookshop or library, you see that it is possible to group fiction into many genres. New genres emerge all the time -- a few years ago, for instance, "chick lit" was unheard of; now it is one of the best selling fiction genres. The most common fiction genre groupings are: - literary fiction - crime - romance - fantasy and sci-fi - blockbusters - historical - short stories - westerns - defined by country, e.g.: Canadian literature ## Arranging collections by genre Many libraries organise part of their fiction collection by genre and the identifying spine labels for the different genres (e.g.: a gun for crime) will be familiar to many library clients. Libraries do this to help clients who habitually read, for example, crime novels. This means that clients regularly go to the same area of stock for their reading material and can miss out on wider reading choices. Some might argue that arranging the non-fiction stock using a classification system removes the need for genres in this area of the library. However, many libraries use genres for some of their non-fiction stock. Common examples are biographies and travel books. For the client who is completely focused on one genre it is undoubtedly helpful if they find all the books in this genre in one place in the library. But the disadvantage of this approach is that it can discourage more adventurous reading. The client may never look beyond the few shelves which contain the selection of "his/her books", even though other books elsewhere could be of interest to them. While some clients will always limit their reading choices to a particular genre, others can, with support, can be led to enjoy reading across a wider range. # Literacy initiatives Literacy initiatives can make a significant contribution to reader development. Such initiatives exist at both local and national level. There are many literacy initiatives related to education. These include the National Literacy Strategy, National Priorities for Education and Literacy Hour. The ability to read fluently is an important life skill and opens doors to better job prospects, improved economic prospects and more leisure choices. In the UK, the issues are about low levels of literacy rather than illiteracy, but 23% of adults in the UK struggle with basic literacy. The website of the National Literacy Trust, <http://www.literacytrust.org.uk> has lots of statistical information. Good functional literacy is important to the well being of individuals as well as the economy of the country and reading/writing abilities are essential for everyday tasks such as writing shopping lists, texting and using medicines properly. Government initiatives to improve literacy in education include the introduction of the Literacy Hour. The National Literacy Trust was established in 1993 to improve skills, confidence and pleasure in reading. The NLT goes wider than formal education and there are well-developed national networks for Adult Literacy and Numeracy support and development. Activity: Go to <http://www.literacytrust.org.uk/projects_networks> and look at the details of the latest literacy initiatives applicable to libraries. Choose those of interest to your own library service and consider how you could use them as part of reader development. ## Examples of literacy initiatives In England, The Reading Agency brings libraries and adult literacy together in partnership and promotions include Got Kids? Get Reading! and First Choice. The Reading Agency runs an annual literacy initiative - the \'Six Books Challenge\' aimed at adults and learners in further education. You can find out more at <http://readingagency.org.uk/adults/quick-guides/six-book-challenge/> In Scotland, the Big Plus brand promotes adult literacy and numeracy. There is a partnership between Communities Scotland's Learning Connections and libraries which is developing projects, collections and providing training. <http://www.thebigplus.com/about/About_The_Big_Plus> Activity: Browse through the following literacy related websites for younger clients. Do any of them have activities which you could link into or adapt for your library service? Note: most of these sites give links to other related sites which may also provide you with inspiration. The Child Literacy Centre <http://www.childliteracy.com> My home library <http://www.myhomelibrary.org> # Reader-centred stock selection When choosing stock it is important that you consider the reading preferences of clients. Using reader-centred selection skills in general stock selection is good practice. You will keep your clients' reading preferences in mind as you take account of current demands, gaps in stock, levels and formats of stock and the condition and currency of stock. You may need to think about developing specific areas of stock. You may also need to select specific items or generate lists for individual clients and their meeting their needs should be the focus. Later we'll discuss what is involved in carrying out an interview with the client to establish their reading history and preferences and in building a reader-profile. Following on from that you will draw on your knowledge of the reading resources available in order to develop a reader-centred list or pathway. Here we discuss some of the resources which are available to assist you in stock selection. Activity: Make a list of the range of resources which are available to you when you are selecting stock to recommend to a reader whose reader-profile you have established. Remember you can be accessing stock which already exists in your library service or you may be ordering new stock for the client. ## Resources For stock within your library service you will use the library catalogue and themed lists such as the Quick Reads collection for emergent readers: <http://www.quickreads.org.uk/> To identify new stock you can use online sources -- there are many online selection tools which are useful in locating resources which your own service does not have. Examples include: Scottish Bibliographies Online: <http://www.scotlandsculture.org/sbo/sbo.htm> Which Book - for widening fiction choice (with reviews from library staff) Other resources for assisting in stock selection include: - catalogues of other libraries - bibliographies - review journals - publishers' lists - pre-publication lists - specialist suppliers - showroom and bookshop visits - trade publications ### Library catalogues Online library catalogues can assist you in your search for appropriate material. Most UK library catalogues can be searched via the Internet. The UK Public Libraries Page <http://dspace.dial.pipex.com/town/square/ac940/weblibs.html> is a useful resource, linking to the web-available catalogues. Some services "clump" together the catalogues of several libraries. A single-search interface is used to cross-search multiple catalogues in a single search action, such as <http://www.ni-libraries.net/> for Northern Ireland or CatCymru for Wales <http://library.wales.org/catcymru/> ### Bibliographies A bibliography is a list of materials on a particular subject or by a particular author. The publication, in either printed or electronic format, is usually arranged by author, date or subject, and provides information such as author, title, publisher and date of publication. This can then be used to identify sources and place orders for clients. Activity: Find out which bibliographies are held in hard copy in your library service and consider how each might be of use to you for reader-centred stock selection. ### Review journals Review journals offer more information about books, articles or research than is found in bibliographies. A review will summarise the contents and make an evaluative statement about its contribution within its context. Good examples include newspapers such as: The Sunday Times <http://www.timesonline.co.uk> The Guardian <http://www.guardian.co.uk/> Remember though, however respected the journal or reviewer, reviews are the views of one individual and so need to be evaluated carefully. ### Publishers' lists Publisher's websites and lists offer useful information. Caution must be exercised when using these to select material as publishers and booksellers have a commercial imperative. So you must always apply your selection criteria. Books from Scotland (http://www.booksfromscotland.com) is supported by Publishing Scotland's website and highlights new books as does their Facebook page (http://www.facebook.com/pages/BooksfromScotlandcom/28776550495) and Twitter feed (http://twitter.com/scottishbooks). They also have an RSS news feed. ### Pre-publication lists These lists offer useful information about forthcoming publications. However, library staff know that they must be especially careful when using information from pre-publication lists as these lists may be produced many months before an item is actually published. In the interval between the pre-publication list and the actual publication of the item, the date of publication, length, format and price may change. ### Specialist suppliers Specialist suppliers are used to ensure that range and depth is developed within collections. This might be a particular interest, specialist language material, dual language material, or alternative formats such as Braille or for emergent readers. ### Showroom and bookshop visits Visits to showrooms and bookshops offer the opportunity to browse through the books. The downsides are that the range is limited to what is available in stock and that it takes considerable time and travel to select from a wide range of stock effectively and efficiently. ### Trade publications The Bookseller is a weekly trade publication, which lists new publications and forthcoming titles <http://www.thebookseller.com>
# Applications of ICT in Libraries/Supporting Client Learning This page is designed for the use of students undertaking the Diploma (Diploma ICTL) or the Advanced Diploma (Advanced Diploma ICTL) in Applications of ICT in Libraries. These qualifications were developed by the Scottish Library and Information Council (SLIC) and are validated by the Scottish Qualifications Authority (SQA) Supporting Client Learning is a core unit in both the Diploma and Advanced Diploma programmes. Information regarding the background to the courses, content and certification opportunities can be obtained by following the Diploma (Diploma ICTL) or the Advanced Diploma (Advanced Diploma ICTL) links. Further information can be obtained from angela.lees@sqa.org.uk ## ICT competence and learning goals ### Establishing client competence in use of hardware and software The client's ICT competence clearly affects their ability to use any learning packages available. If ICT skills are lacking, the client may have to undertake some ICT skills development before moving onto their selected learning package. You should determine the client's ICT competence in relation to both hardware and software. Your initial task is to find out what sorts of previous experience and competence the client has had with ICT. Typically you might want to explore four areas: - hardware - operating system environment (normally Windows) - using the Internet - using applications packages ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.1 Before proceeding: - List the hardware items you would enquire about. - Note down what you would want to know about each of these items. ------------------------------------------------------------------------ #### Client competence in using hardware The main items of hardware which the client is likely to have to use are the: - mouse - keyboard - printer - scanner - removable media We look at each of these in turn, giving some specific pointers about what you should ask the client. #### The mouse You might want to start by finding out the following information: - Has the client used a mouse? - Is the client aware of the use of the left and right buttons? - Is the client aware of hovering over items? - (For left handed clients) is the client aware of how to change a mouse from right- to left-handed operation? - If the computers in your library use another type of pointing device, such as a tracker ball or touch pad, can the client use this proficiently? #### Keyboard You might want to start by finding out the following information: - Has the client used a keyboard? - Does the client know how to use: - space and return keys - shift and caps lock keys - delete and backspace keys - cursor (arrow) keys - ctrl, tab, esc and insert keys - function keys #### Printer You might want to start by finding out the following information: - Has the client used a printer? - Is the client aware of any printer processes which are \'specific to your library? - Can the client load the printer with paper? - Is the client aware of the cost per page of printing (monochrome and colour)? #### Scanner You might want to start by finding out the following information: - Has the client used a scanner? - Is the client aware of the routine of pre-scan, select area and scan? - Is the client aware of the importance of selecting an appropriate scanning resolution? #### Removable media Use of removable media, such as floppy disks, CD-ROMs and USB storage (also known as Flash Drives or Pen Drives) will be governed by library rules. If these are allowed you might want to start by finding out the following information: - Can the client insert a disk (or other media) properly? - Is the client aware of when it is appropriate to remove it? - Can the client access media in different drives? - Can the client save to writable media? #### Operating systems We use the term operating system to describe the basic software, such as Microsoft Windows, which makes the computer work. When a computer is switched on, the operating system starts running before any application package such as Word will run. The operating system involves managing applications and data. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.2 Before proceeding: - List the aspects of the operating system you would enquire about. - Note down what would you want to know about each aspect. ------------------------------------------------------------------------ #### Previous experience You might want to start by finding out the following information: - Is the client familiar with the operating system on the computers in your library? Note that, even within the same library, different computers may have different operating systems. Most of the common operating systems are supplied by Microsoft: - Windows 98 - Windows NT - Windows 2000 - Windows Millennium - Windows XP There are some significant differences in the practical operation of these, so you should determine whether the client can carry out the tasks we outline below for the operating system on the computer which will be used to work through the chosen learning packages. #### Operating system tasks You might want to start by finding out the following information: Finding applications: - Does the client know where to look for the applications or packages? - Does the client know the names and icons for the applications required? Opening and closing applications: - Can the client open an application? - Can the client close an application correctly? (This often involves saving information.) Using a file manager to locate files and data: - Can the client use My Documents/Windows Explorer to navigate around the file system? - Is the client aware of the concept of a hierarchy or tree structure of folders (directories)? Creating folders and saving data in specific folders: - Can the client create a new folder to save application data? #### Using the Internet A great deal of information to support learning as well as complete learning packages can be accessed via the Internet. It is therefore important to gauge the client's competence in Internet use. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.3 Before proceeding: - List the aspects of Internet use you would enquire about. - Note down what would you want to know about each aspect. ------------------------------------------------------------------------ #### Common Internet tasks Here are the main aspects of basic Internet use which you should ask about: Browsing the Internet: - Has the client experience of using a browser? (e.g.: Internet Explorer, Mozilla, Firefox) - Has the client experience of using a search engine? (e.g.: Google, Ask Jeeves) - Is the client aware of the variable quality of websites found on the Internet? E-mail: - Has the client used e-mail? - Does the client have an e-mail address? Chat: - Has the client used chat? - Is the client aware of possible dangers in its use? Groups: - Has the client used any (news)groups? #### Using applications packages You need to know about the client's existing experience with common applications packages. This will help to confirm the information gleaned so far. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.4 Before proceeding, list some applications packages you might want to ask about. ------------------------------------------------------------------------ #### Applications packages Word processing is the most likely example of an applications package. Almost all computer users will have done some word processing. But many will have used other packages as well. Word processing packages - Has the client used a word processor? (e.g.: Word, Write) Spreadsheet packages - Has the client used a spreadsheet application? (e.g.: Excel) Photo/Graphics packages - Has the client used a photo/graphics package? (e.g.: Paint Shop Pro, Photoshop) Database packages - Has the client used a database application? (e.g.: Access, dBASE) Financial packages - Has the client used a financial package? (e.g.: Quicken, Quick Books) Other - Has the client used any other, more specialised packages which do not fit into the above categories? If so, what are these packages and what do they do? In each case you should try to get an idea of the level at which the packages have been used. The best way of finding this out is to ask the client to give some examples of how they used the package. #### Using learning packages One important question to ask is whether the client wishes to use the chosen learning package in the library, using the library's equipment, or whether they would prefer to take the package away for home use. If the latter, it is vital that you establish the specification of their home computer. While many home users possess high specification equipment, others may have older, slower models which will not support the latest packages. This can be a particular problem where graphics or audio is involved. All learning packages will state clearly the minimum specification on which the application will run and you should ask the client to confirm that their home equipment meets or exceeds this. It is good practice to make a written record of what you have established about the client's ICT competence. Some libraries have checklists for this purpose. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.5 Find out if your library service has checklists of this nature. If not, why not create one for yourself and your colleagues to use? ------------------------------------------------------------------------ #### Establishing learning goals You need to establish the learning goals for the client before you can think about possible learning approaches. The client may have learning goals related to their work or to their personal life. You should attempt to establish exactly what the client wishes to learn and if possible get an idea of the reasons why the client is undertaking the learning. Some clients may come to the public library seeking learning packages which are complete in themselves. You may be able to provide such packages "off the shelf" in your library or you may have to source them from elsewhere. Other clients may be seeking additional learning to support training or education being undertaken elsewhere. The most obvious example of the latter is school pupils or college/university students wishing assistance with assignments or desiring materials which will help them revise for examinations. Clients engaged in more informal learning may also require top-up materials. For example, an adult working through a self-help book on word processing might ask for additional exercises in keyboarding. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.6 Before proceeding outline the different areas you would need to ask about to find out the client's learning goals. There are quite a few of them! ------------------------------------------------------------------------ #### Determining learning goals Here are some possible areas to look at with the client to determine the learning goals: General subject area: What is the general subject area in which the client wishes to undertake the learning? E.g.: the Spanish language. Slant or specialism: Is there a particular specialism to this learning? E.g.: Spanish for business. Existing competence of client: Does the client possess any existing relevant competence in the subject? E.g.: the client has picked up a basic knowledge while living in Spain for six months last year. Future competence as a result of the learning undertaken: What level does the client wish to be able to reach as a result of the learning? E.g.: the client wishes to write business letters to Spanish clients of their company. Reasons for learning: Is there a particular work or social reason the client has for wishing to undertake the learning? E.g.: the client is soon to take responsibility for their company's Spanish clients #### Additional factors You may need to consider the following additional factors: Timeframe: Over what time period does the client wish the learning to take place? E.g.: the next six months. Time available: How much time in the week does the client have for learning? E.g.: up to four hours per week. Importance of certification: Does the client particularly want to undertake learning which will result in a qualification? E.g.: the client is interested in gaining a City & Guilds qualification in Business Spanish on completion of the learning. Finance: Many of the learning materials available through public libraries will have no costs attached. However some may involve enrollment or certification fees. In these cases, you must tactfully investigate if the client would have the financial resources for a course of study with a fee associated? E.g.: is the client able and/or willing to pay for an end of course examination fee? It is good practice to make a written record of what you have established about the client's learning goals. Some libraries have checklists for this purpose. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.7 Find out if your library service has checklists of this nature. If not, why not create some for yourself and your colleagues to use? ------------------------------------------------------------------------ ### The UK education and training system In order to help your clients, you need to have a broad-based understanding of the UK education and training systemas a whole - pre-school, primary, secondary, tertiary, workplace and informal. Naturally you are not expected to be an expert on education and training (although in some instances you may need to consult such experts). However you should be familiar with the basics of the system and know how to find out more detail on any aspect, if this is required. Remember that we live in an age of lifelong learning and that much learning takes place outside the traditional academic system. So you should make sure that you know not just the local schools, colleges and universities, but also private training providers, adult learning agencies, voluntary groups etc. In particular, it is essential that you appreciate the ways in which the education and training systems of the four UK nations differ from one another (the Scottish system displays the largest divergences from the others) and the implications of this for the client. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.8 Here are the official government websites for the education departments in England, Northern Ireland, Scotland and Wales: - England: <http://www.dcsf.gov.uk/> - Northern Ireland: <http://www.deni.gov.uk/> and <http://www.delni.gov.uk/> - Scotland: <http://www.scotland.gov.uk/Topics/Education/> - Wales: <http://www.learning.wales.gov.uk/> Familiarize yourself with the information provided on these sites, especially that related to the country in which you are resident. Note that much of the information on the English site applies also to Wales and some is also applicable to Northern Ireland.Each of these sites provides links to sites giving information on more specialised aspects of education. Note the addresses of such sites which are particularly relevant to yourself and summarise the sort of information which you can gain from them. ### Ascertaining special needs You should establish any special needs (in the widest sense) of the client which will have a bearing on the learning they are proposing to undertake. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.9 Before proceeding: - Make a list of the different types of special needs which could have a bearing on the learning. - For each case note the steps you can take to enable the learning. ------------------------------------------------------------------------ #### Types of special needs It is difficult to compile a comprehensive list of special needs. Here are some of the most common with some suggestions as to how the library can facilitate learning for such clients. - Motor disabilities - Visual impairment - Hearing impairment - Special learning needs (including literacy, numeracy and English as a second language) #### Motor disabilities This can cover a wide range of disabilities, ranging from a paraplegic learner in a wheelchair to someone with mild Repetitive Strain Injury (RSI). Some common examples of library facilities for this group are: - a flexible computer desk at a height which can be adjusted to suit varying dimensions of wheelchairs - a joystick or specially adapted mouse for clients who cannot operate a standard mouse - a specialised "big keys" keyboard etc. for clients who cannot operate a standard keyboard - a mouse tray so that clients can use the mouse on their lap - touch screens - programmable keypads to reduce the number of keystrokes required for common inputs #### Visual impairment Many manufacturers produce software specifically to enable use by visually impaired users. It is possible for the users to hear what appears on the screen. Some software produces output in Braille. Sometimes simple measures can be effective in facilitating use by visually impaired clients, such as: - changing the text size on the screen - altering the colour settings (It is usually easiest for clients with visual impairments to read black text on a white background) - using "text only" versions where graphics are removed. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.10 Make sure that you can carry out the three "simple measures" listed above. Useful information can be found on the website of the Royal National Institution for the Blind. Go to <http://www.rnib.org.uk/> and search for "internet". ------------------------------------------------------------------------ #### Hearing impairment Again much specialist software is available. Libraries can install systems which pick up sound from the computer through an amplifier and radio microphone which is then transmitted by infrared around the room. The hearing impaired person hears this amplified sound through a lightweight headset. There is no need for users to wear their hearing aids. <http://www.deafclub.co.uk> is a useful site with a search engine, which is specifically designed to help deaf people find information. It can also lists sites giving advice on ICT adaptations for clients with hearing impairment. <http://www.rnid.org.uk/> is the site of the Royal National Institute for Deaf People. #### Special learning needs Public libraries have always played an important role in assisting clients in these groups and recent disability and discrimination legislation has laid even more emphasis on this role. Research has shown that libraries are often viewed by such clients as friendly, non-judgmental environments. In consequence they may be more likely to undertake learning in the library than in the more formal setting of a school or college. Your library service will have staff who specialise in assisting these user groups. These colleagues can advise you of how best to provide for individual clients. You should be aware that nowadays, there are many holistic learning packages which provide upskilling for young people or adults in literacy, numeracy and ICT. Remember that, although the word processor's spell checking facility is designed primarily to check for typing errors, it is an invaluable aid to anyone with problems in coping with the English language's idiosyncratic spelling. ### Sources of careers information In order to match the client's learning desires with work goals, it may be necessary to have information about which workplace qualifications and competences are useful in a particular job role or career. You are not expected to know this information but you should to be able to access it efficiently, most probably by use of the Internet. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.11 Before proceeding, find websites which will give you information on the following careers: - nursing - clockmaking - actuarial work - farriery ------------------------------------------------------------------------ #### Careers information sites There are several different sites which will produce the required information. There is usually a dedicated site for each sector of employment. Here are some examples for the jobs we asked about: Nursing An NHS site <http://www.nhscareers.nhs.uk/careers/nursing/> Clockmaking The British Horological Institute <http://www.bhi.co.uk/> Actuarial work Prospects the graduate careers website has a section at: <http://www.prospects.ac.uk/cms/ShowPage/Home_page/Explore_types_of_jobs/Types_of_Job/p!eipaL?state=showocc&idno=329&pageno=1> Farriery The Farriers Registration Council has a section on careers at: <http://www.farrier-reg.gov.uk/> #### General careers information There are several useful on-line sources of general careers information, such as: - For England <http://www.connexions-direct.com> - For Scotland <http://www.careers-scotland.org.uk> - For Wales <http://www.careerswales.com/> - For the whole of the UK <http://www.careers-gateway.co.uk> Web 2.0 sources University of Glamorgan YouTube <http://www.youtube.com/careersglamorganuni> Foreign and Commonwealth Office Twitter links <http://web.archive.org/20090804213504/www.fco.gov.uk/en/twitter/> Energy careers on Facebook <http://www.careerenergy.co.uk/?facebook> CILIP Graduate Trainee Opportunities on Facebook <http://www.facebook.com/group.php?gid=13484212748&ref=nf> ## Select a range of ICT-based packages to support learning ### Selection criteria You must take all the information obtained from the client into account so that you can identify learning packages which will meet the criteria. You will match learning packages against such criteria as: - Does the subject matter match the client's desired study topic? - Is certification available if the client desires this? - Does the length of the learning package fit with the time available for the client to learn? - Can the client afford any costs associated with the learning? - Does the learning package address any special needs of the client? - Is the level of the learning suitable in terms of both starting competence (i.e.: neither too easy nor too difficult) and final competence achieved at the end of learning? - Can the client undertake this learning without enhancement of their existing ICT skills? If not, can the library supply additional support for ICT skills development in order to enable the client to undertake the chosen learning package? ### Learning packages available within own organisation You need to be aware of the range of learning packages which are available within your own library service. Some of these will be at your own service point. Others will be held elsewhere within the service. The library catalogue will give information about the learning packages, both in your own library and elsewhere. Some libraries produce specific catalogues or lists of ICT learning packages, giving more details than might be found in the general catalogue. For packages at your own service point, it is also useful to examine the packages themselves and, if time permits, you can actually test them out. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.1 Familiarise yourself with all the catalogues and lists of ICT learning packages in your library service. Note what sort of information they provide for each item. ------------------------------------------------------------------------ #### Restrictions on the use of learning packages You must be able to determine any restrictions on the use of ICT learning packages, e.g.: - Must the package be used on library premises or is it available for home use? - Is there a limit to the number of hours a client may book to use the package in the library or on the length of time a package can be borrowed? - If the packages are to be used in the client's home it is vital for you to establish the details of the client's own computer in order to be sure that the specification is high enough to support the chosen learning package. When working in this area you will pick up useful information through the experience and comments of clients. If several clients recommend a particular package on keyboarding techniques, for instance, you can feel confident in recommending it to other clients with similar learning goals. Additionally you can gain information and advice through discussions with experienced colleagues. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.2 Here is an exercise to familiarise yourself with some learning packages available within your own library service.For each subject area given below, find two packages and note the differences between them: - Business studies - French language - Basic mathematics - Word processing ------------------------------------------------------------------------ ### Sourcing learning packages outside own organisation Your library cannot duplicate all the learning packages which will exist locally outside your library service. You must have an awareness of what is available out there. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.3 Before proceeding make a list of the types of organisation in your locality which produce and/or deliver learning packages. ------------------------------------------------------------------------ #### Sources of learning packages Here are some examples of where learning might be found in the locality: - Schools - Further education colleges - Universities - Private trainers - Local learning partnerships - Community learning - Voluntary organisations, e.g.: Workers' Educational Association ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.4 Here is an exercise to increase your familiarity with local sources of learning material outside the library service. Choose four of the types of provider given in the preceding list. For each type, find the website of a named organisation in this category and choose two different study packages offered. Note the differences between the packages at each organisation and the differences between the organisations. ------------------------------------------------------------------------ #### Differences between sources We expect that you will find the following points of difference: - Cost of package (if any) - Flexibility of study times - Availability of certification - Level of studies - Range of content In fact, you should come up with the very points which might be criteria gleaned from a client seeking learning. With e-learning it is not necessary for the provider to be local. Much excellent learning content can be sourced free of charge from the Internet e.g.: <http://www.studyspanish.com> offers free tuition in basic Spanish. In other cases e-learning may be delivered via the Internet for a fee. In these cases a log in and password will be required after registration. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.5 Before proceeding, find and note down five websites where learning is available on the Internet. ------------------------------------------------------------------------ ### Learning on the Internet Learning can be found on the Web at many, many sites. There is no way that you will be able to remember even a fraction of these. So it is extremely important that you should be familiar with sites which are commonly used to find learning resources. Check these sites frequently for news and developments, as their content is regularly updated. It is important to be aware of the scope of any such site. It is often the case that learning sites which appear to be UK-wide are not in fact applicable to one or more of the four nations. Frequently, learning sites apply to England, Wales and Northern Ireland (e.g.: <http://www.learndirect.co.uk>) and there is a separate site for Scotland (e.g.: <http://www.myworldofwork.co.uk>) The scope is not always obvious from the title of the site. Be especially careful when the word \"national\" is used. This can mean UK or a single one of the four UK nations. For example, the content of the National Learning Network (http://www.nln.ac.uk) applies only to England. In contrast, the content of the National Learning Network (http://www.nln.ac.uk) applies only to England. #### BBC learning materials The BBC (http://www.bbc.co.uk) offers excellent learning materials most of which are applicable in all four UK nations. This site also provides links to other providers of on-line learning. There are many websites which are specifically designed to provide curriculum related resources and revision aids. Once again it is vital to check that these are appropriate for the school or college curriculum of the UK nation where the client is studying. The BBC's site (http://www.bbc.co.uk) has educational and revision material for England, Northern Ireland, Scotland and Wales. You should be familiar with websites applicable to your own home nation's educational curriculum, such as Learning and Teaching Scotland (http://www.ltscotland.org.uk). However, do not consider that support learning should be confined to these educational web sites. Rather be prepared to assist clients to find appropriate support material for their learning from any suitable Internet source. This applies especially when the client is seeking information to enhance a course of study undertaken elsewhere. They may come to the library looking for company financial performance data to include in a presentation on marketing, literary criticism of T S Eliot for a university essay or information on the breeding habits of dolphins for A level biology. This sort of information in support of learning will probably be found on websites which are not specifically educational. So be prepared to assist your client to find information in support of their learning from any appropriate Internet source. ### Devising a learning plan You can give the client additional help in the form of a motivational learning plan to guide the learner through the package(s) you have sourced. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.6 Before proceeding, make a list of points which you might include in the plan. ------------------------------------------------------------------------ #### Contents of a learning plan A suitable set of features to be included in the learning plan is: - the overall learning goal - specific learning objectives which contribute to the learning goal - a deadline for completion of the learning - a schedule for learning - any support which the library staff have agreed to provide for the client - a specification of the responsibilities and involvement of any outside provider The learning plan is best expressed in SMART (Specific, Measurable, Achievable, Realistic, Timebound) objectives. It need not be a complex piece of documentation. Often it can simply be a checklist. This plan should be created with and agreed by the client. Usually it will be signed by both the client and a member of library staff. The use of such a learning plan avoids confusion and can also be motivating to the learner. Where the client is returning to learning after a gap, or has had prior negative learning experiences, it can be helpful to break the learning into "bite sized chunks" and produce a series of shorter learning plans. Thus the client has a positive experience of successfully completing a small amount of learning which engenders a sense of achievement and spurs them on to further efforts. #### Example of a learning plan ![](2Learning_Plan.png "2Learning_Plan.png"){width="500"} ### Progression opportunities An important role of the public library is to be a key player in lifelong learning. A positive learning experience provided by the library can lead to further successful progression for the client, in some cases into formal tertiary or workplace vocational education. The library user who enquires about opportunities to study Spanish language to further her career in retail sales may eventually undertake a university course in business and retail management. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.7 Before proceeding note down how you might explore progression opportunities for a client. ------------------------------------------------------------------------ #### Exploring progression opportunities You could explore the following possibilities: - What has been the client's experience with the learning undertaken so far? Have they enjoyed it? What was particularly enjoyable or useful and what was less so? - Revisit the client's original reasons for undertaking the learning. Are these motivations still the same or has the experience of learning awakened the client's ambition to broader horizons? It is not uncommon, for example, for a learner who has embarked on a short language package, with a view to being able to order food and ask directions on holiday, to be seized with enthusiasm and wish to carry on to GCSE or Standard Grade qualifications in the language. Based on this discussion you can consider any or all or the following: - Is there a more advanced package on this topic available? - Are there packages on related topics to that being undertaken by the client? - Has the client come to the end of the possible informal learning on the topic and might now proceed to formal education? - Which further learning will further enhance the client's job prospects after the present studies? Of course, all of the previously mentioned sources of information on learning provision are useful to you not only in sourcing learning which is appropriate for the client's immediate learning goals but also to suggest further learning options to the client, on completion of the initial learning. In other words, at its simplest, when you are sourcing learning material, you should always have your eye on the level above, to see how your client might further progress. #### Concluding the learning experience Hopefully the learning has been a positive experience for the client and they are interested in taking things further. But do not be discouraged if the client does not want to sign up for further learning immediately. It may be that the learning just completed has achieved all the client's current goals and they wish to pause at this point meantime. This is a satisfactory outcome because you can be sure that a satisfied client who has found the package stimulating and relevant is likely to return to the library in future looking for advice and guidance on other learning. ## Provide appropriate ICT support to the client ### Using in-house learning packs to develop ICT skills Most public library services have a wealth of in-house learning packs whose aim is to develop ICT skills, ranging from beginner to advanced level. You should examine the packages in your library so that you are completely familiar with their content and level. This enables you to make the most informed choice when recommending a package to a client and to be absolutely confident that the client will benefit from it. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.1 Select three in-house packages which develop basic ICT skills such as: - Using PC hardware - Using files and folders (directories) - Using the Internet - Keyboarding skills Try out each of the three packages to evaluate: - Level (absolute beginner to expert user) - Duration (how many hours to work through whole package) - Approach (friendly to overly formal) - Ease of use - Presentation (is it attractive and encouraging for the learner?) ------------------------------------------------------------------------ ### Front-line client support When a client is using any ICT based learning package in the library, whether to develop ICT skills or for other learning, it is likely that from time to time some technical snags will arise. You must be able to assist with straightforward trouble shooting e.g.: printing problems. We stress the word "straightforward". There is no suggestion that you should possess sophisticated trouble shooting skills: this is the responsibility of ICT technical staff. Rather you should be acquainted with typical, straightforward difficulties which can arise and be able to suggest how these can be overcome. Do be clear about the boundary between your responsibilities regarding trouble-shooting and when to call on the services of a technical professional. You probably have had experience of this already. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.2 Before proceeding, note down a few possible problems which may be encountered by clients using computers. (If this is outside your own experience ask colleagues to suggest computer problems they have solved for clients.) ------------------------------------------------------------------------ ### Typical problems Here are some of the problems you are most likely to encounter. - The monitor appears blank - After using the computer for some time, it 'hangs', neither keyboard nor mouse appear to operate - A client has difficulty reading off the monitor because the print is too small - Nothing comes out of the printer - The printer does not seem to use the whole of the sheet of paper and the layout is not the same as on the monitor - When saving data from an Office application like Word, the message comes up that the disk is full - The printer jams ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.3 Before proceeding, jot down any ideas you have about the help you would be able to give in each of the above cases. You can compare this with our suggestions on the following screens. You will find that with experience and in discussion with your colleagues you will build up a fund of solutions for these types of problem. Once again, as in Outcome 2, you must take full cognisance of any special needs of the client and offer appropriate technical support to address these. ------------------------------------------------------------------------ #### Resolving problems Some of our solutions are based on your ability to change computer settings. It may be that you do not have access rights to these and would need to contact an ICT professional. Note that with the first two faults (monitor blank, computer hanging), if they require forcing an application to end or indeed resetting or restarting the computer, it will always mean any data not saved will probably be lost. It is important to explain this to the client. It is even more important to explain before any incident occurs that data should be saved at regular and frequent intervals just in case something goes wrong! #### The monitor appears blank - Check to see if the computer has gone to sleep by pressing the space bar on the keyboard. - Check that the monitor is switched on and connected to the mains, i.e.: is the power light illuminated? - Check that the monitor is correctly connected to the computer. - Check to see if the system works after the computer is reset or switched off at the mains and on again. #### The computer hangs Sometimes, after using the computer for some time, it hangs, and neither keyboard nor mouse appears to operate. If this happens you can try the following - Wait a while to see if the computer is performing some intensive task and recovers. - Try Ctrl-Alt-Del. If you are lucky it will bring up a Task Manager window which will show you which application is not responding and allow you to close down only that application. - Use the reset button to restart the computer. - Switch the computer off at the mains and then on again. #### A client has difficulty reading off the monitor because the print is too small - If this is confined to a particular application, it is usually possible to adjust the zoom setting. If this does not appear in a box near the top of the window, it will be found in the menu system under View: Zoom or View: Text size. - If this applies to everything on the monitor, then, if you have access rights, you can change the monitor settings. Right click with the mouse on the desktop, choose Properties from the resulting menu, choose the Settings tab from the dialogue box, reduce the Screen resolution setting and OK. Unfortunately, the lower the screen resolution, the less can be displayed on the monitor. This often results in an uneasy compromise for people with problems with their sight. #### Nothing comes out of the printer - Check that the printer is switched on and connected to the mains, i.e.: is the power light illuminated? - Check that the printer is correctly connected to the computer. - Check that the printer has paper in it. - Check the ink supply. - Try printing a test page. - Check the print settings in both the operating system and the application to see that the computer is looking for the correct printer and that the correct size of paper has been selected and that manual/auto (as appropriate) is chosen. #### Print layout is incorrect Sometimes the printer does not seem to use the whole of the sheet of paper or the layout is not the same as on the monitor. - When using a word processor like Word, it is possible to set the paper size in the application. However there is also a setting for the printer itself. If these two settings are different, then the output will not appear correctly on the page. The driver for a newly connected printer may default to US legal for the paper size. It is normal to use A4 in this country and applications will use this as default. Go to the printer properties and check the paper size. Start: Settings: Printers: right click on the printer concerned, choose Properties and select the Device settings tab. #### The disk appears to be full Sometimes, when saving data from an Office application like Word, a message comes up that the disk is full. - It may be that the client's floppy disk or pen drive is full. This is quite likely for any sizable word-processed document especially if it contains graphics or other embedded items. - A fault condition can arise concerning interaction between the application and the operating system which results in a false reporting of the disk full error. This is irretrievable and requires the computer to be rebooted. If the client will lose a fair amount of unsaved data, it is worth opening a new document and copy and pasting from the original to the new document and then trying to save that. You may be lucky! - A similar problem can occur regarding the computer running out of memory. Again only rebooting the computer will correct the situation. #### The printer jams - There is no universal solution for this problem as each printer has its own unique mechanism. The best you can do is to familiarise yourself with the various types of printer in your library and how to un-jam each. ### Referring clients to sources of support external to library Where no suitable in-house packages are available, you will need to refer the client to external sources. These are likely to be hands on, practical courses from local providers. The knowledge of local provision outlined under Outcome 2 will enable you to suggest appropriate referral agencies. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.4 Before proceeding, make a list of the types of packages which are not available from your library service and would need to be sourced from outside. ------------------------------------------------------------------------ #### External sources of support As in Outcome 2 you will find ICT skills packages in the locality from: - Schools - Colleges - Universities - Private trainers - Local learning partnerships - Community learning - Voluntary organisations, e.g.: Workers' Educational Association ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.5 Here is an exercise to increase your familiarity with sources of ICT skills materials outside the library service. Choose four of the types of provider given in the preceding list. For each, find the organisation's website. Locate at each two different ICT skills packages being offered. Note any differences between the packages at the different organisations. You should repeat this exercise for ICT learning packages available over the Internet from providers outside your own locality. ------------------------------------------------------------------------
# Applications of ICT in Libraries/Using ICT in Professional Practice This page is designed for the use of students undertaking the Level 7 PDA (Diploma ICTL) or the Level 8 PDA (Advanced Diploma ICTL) in Applications of ICT in Libraries. These qualifications were developed by the Scottish Library and Information Council (SLIC) and are validated by the Scottish Qualifications Authority (SQA) Using ICT in Professional Practice is a core unit in both the Diploma and Advanced Diploma programmes. Information regarding the background to the courses, content and certification opportunities can be obtained by following the Level 7 (Diploma ICTL) or the Level 8 (Advanced Diploma ICTL) links. You will have received on-site training allowing you to develop specific operational knowledge of your library management system. This might have been provided by the supplier, the systems manager or other library staff. In some cases your job role may not allow you to get practice in all of the operations we describe in this Outcome. If this is the case, you must at least understand what is going on and see demonstrations of the operation. As an example, relatively few staff may actively add new items to the catalogue but it will help your understanding of the operation of the system as a whole if you can observe new items being added. You should know where to find information or instructions on procedures relating to the use of the library management system. If necessary you can create some "crib guides". \-\-\-- ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.1 You should have a good knowledge and understanding of the system and its workflows. As an exercise, taking a typical item, such as a work of fiction, draw up a flow chart which lists what happens at each stage from stock selection, through the ordering and acquisitions process, to the point when the item is made publicly available and is visible on the catalogue. ------------------------------------------------------------------------ #### Borrower information The two main elements in an automated system are the borrowers and the stock items. The basic information held on the borrower, apart from name, is address and contact details. There are usually several classes of borrower. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.2 Before proceeding, jot down the different classes of borrower you are aware of, and what the key differences are between them as far as the automated system is concerned. ------------------------------------------------------------------------ #### Types of borrower The main categories of borrower, common to most public libraries, are: - adult - teen - junior - concession (e.g.: senior citizen, person in receipt of benefits) - disability (e.g.: visually or hearing impaired) - housebound - temporary (e.g.: transient worker) You may have noted others. The key differences are likely to be: - limits on the type of items allowed, e.g.: junior borrowers may not borrow adult stock without a parent\'s permission - different loan periods for different categories of borrower, e.g.: no limit on length of loan period for borrowers with disabilities - the scale of fines may vary with the different classes of borrower, e.g.: no fines for concessionary borrowers. #### Registering and removing borrowers The precise details of registering and removing borrowers can vary significantly depending on the system in use at your location. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.3 Note down the steps you need to go through to: - register a borrower with the system. - remove a borrower from the system. ------------------------------------------------------------------------ In addition to the borrower details which are permanently on the system, it may be necessary from time to time to add a temporary message to alert members of staff to something connected with a particular borrower. Some of these messages may be added automatically by the system. Typical would be information about money owed by or due to the borrower. Staff will also be able to add specific messages. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, jot down some examples of messages which you might wish to add about borrowers. ------------------------------------------------------------------------ #### Messages about borrowers You might want to ask for some of the borrower data to be verified, e.g.: if you have tried unsuccessfully to contact the borrower by telephone, you could add a note asking for the telephone number to be checked. Other data which sometimes changes (and borrowers neglect to inform the library) are home address and e-mail address. Messages could be of a more personal nature "Mrs Jones left her umbrella in the library on her last visit. It is in the lost property cupboard." Or "Tell Mr O'Neill that we have got some good new stock in about the Atkins diet." With these sorts of messages, do be careful to keep them factual. Data protection legislation means that borrowers are entitled to read any information stored in a computer about themselves. Remember to delete these messages once they are no longer applicable. Mr O'Neill will be pleased to be told once about the Atkins diet books but he will not appreciate being reminded of them on every visit to the library! ### The circulation module Issuing and discharging items of library stock using an automated system is usually quick and straightforward. Sometimes the system will indicate a complexity in the transaction, e.g.: you are prevented from issuing an item to a borrower. Although in almost all cases the system will supply you with correct information regarding the status of the borrower and their borrowing activities, the underlying reasons may not be displayed on the screen. However, you have to be able to explain the actions of the system to the borrower. This requires both an excellent understanding of the library authority rules (which guide the system) and the ability to access quickly the required screens of the system to find the reasons for the system\'s decisions. You should have a good understanding and have had practice in the main operations of the circulation module of the system. Issuing items This is the basic action of entering the issuing details, i.e.: borrower and item barcodes on to the system. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, jot down problems that may occur with this task. ------------------------------------------------------------------------ #### Problems with issuing We can think of several problems, such as: - With self-issuing systems, where the borrower is able to carry out self-issue over the Internet, borrowers, especially if they are inexperienced in doing this, can easily make a mistake. - The system indicates that the borrower\'s lending limit has been reached. - The borrower would like at this point to know which other items they have out on loan. - Different classes of items may have different loan periods, e.g.: DVDs may need to be returned within three days. Certain types of book may be lent for only one week instead of the general three weeks. The system may prompt you about this but you have to remember use the correct date stamp on the item. You must be able to deal with these situations and be aware of relevant library policies so that you can communicate quickly with the borrower and explain the reason for any problems. #### Discharging items Most automated systems allow items to be discharged by entering only the item barcode. They do not require borrower information to be entered. This makes discharging items a simple and fast operation. However, additional steps are sometimes required. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, jot down problems that may occur when discharging items. ------------------------------------------------------------------------ #### Problems with discharging items We can think of several potential problems, such as: - The returned item is damaged. This must be shown on the system and the book sent for repair or disposal. - The returned item is subject to a request by another borrower or an inter-library loan. The system will prompt on this and you must follow reservation or ILL procedures. #### Other circulation tasks - Renewing items: this is a variation on the issuing procedure. However, it may be a renewal over the telephone. This requires you to manually input the details into the system. - Reserving Items: make sure that you are familiar with the steps you must carry out on the system to input a reservation. - Overdues: most automated systems generate overdue notices automatically and the screen will show any fine incurred by the borrower at the point of return of the item. - Charges and Fines: reservations often require charges to be made to the borrower. Charges may also be made for interlibrary loans. The other common financial transaction is related to fines for late return of items. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.4 Make a list of the charges your library make to borrowers which must be administered via the library\'s automated system. ------------------------------------------------------------------------ Data provided by the circulation control module of the automated management system can make a significant contribution to the successful management of stock. Used properly, the system can provide data on usage for managers to support their decisions in areas such as stock selection policy, opening hours, staffing levels, distribution of stock and information for statutory and local performance indicators. A particular use of the library management system is in monitoring the performance (levels of issuing of resources) of existing stock. ### The acquisitions module Once new stock to be purchased for the library has been selected (the selection process is covered in outcome two of this unit) the automated system plays a prominent part. Although details will differ, there are three clear steps - ordering, receipting and invoicing. The system then will allow the acquisitions process to run, using its Reporting Systems and Order Transmission. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.5 Find out the procedures for placing and receiving stock orders on your automated library system and how this interfaces with the system\'s monetary reporting facility. ------------------------------------------------------------------------ The above are the procedural steps. However, the automated system is equally powerful in aiding the acquisition process when it comes to financial control. The acquisition of new items for your library stock is governed principally by an acquisitions policy. Different library authorities will have different methods but the following is the basis of the process: - The total level of resources available for the library service as a whole is set. - Priorities for spending are agreed. - The total budget is then broken down across the various budget headings, e.g.: fiction, non-fiction, DVDs, allocations to different branches etc. - Budget holders are informed of their budget allocation and acquisitions may proceed. It is important that you clearly understand the boundaries of your personal authority within the ordering of any stock selection process. You may be permitted to place orders or this may only be done by a more senior member of staff. Know what responsibility you have and your accountability for actions within your remit. Clearly the whole process of acquisitions is based on the availability of funds to enable the purchase of new stock items. Thus, there is always a very clearly defined method of deciding how much money can be spent on the various types of new stock item. The joy of an automated system is that it can give really hard data to inform the acquisition process. It will give the spending situation under the various budget headings. This includes both the projected and the actual spending to date. Although you may not need to access this management information, it is important for you to realise that you have a vital part in this. You must always enter order information accurately to ensure the system has the correct data for its calculations. Of course there is also non-financial information in the data. For instance, it can also give information on the performance of the various suppliers used by the library. This allows the library managers to select the best performing suppliers for future orders. ### The cataloguing and stock management modules A library catalogue has two main functions: 1. it is a record of the items which comprise the library stock 2. it allows people to seek out suitable items they wish to use The first appearance of automated systems in libraries related to automation of the library catalogue. In the late 1960s computers became powerful and available enough to allow libraries, particularly academic libraries, to embark on 'computerising' their catalogues. It is easy to see why this was more attractive than going for the circulation system first. Users could use searching techniques to find book titles by keywords. Networks were beginning to appear so that it became possible to search for titles in other libraries remotely. You must compare this with the position up till this point of using paper or card indexes to find a book only by its author or subject. From the user\'s point of view the cataloguing module of the automated library system is the most powerful and useful part of it. Of course the user has to learn how to use it to advantage, as indeed do those who work in the library. #### The advantages of automated catalogues The advantages of automated catalogues are twofold: 1. They permit sophisticated searching of the library stock. 2. They link to the circulation control system so that not only can a borrower ascertain that the library service holds a particular item, they can also see its loan status at the time. The search facility of the catalogue module is very flexible. It will allow searching for items on author, title, accession number as well as classification. However its greatest power for users is to search on subject keyword or word in title. You will no doubt have to demonstrate this feature to keen users of your library. In your administrative work related to the catalogue, i.e.: stock management, you are most likely to be locating items whose details are known. You will be searching on author, title or accession number. Having found the item, you may need to withdraw it, thus deleting its entry in the catalogue. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.6 Note down the procedure to withdraw an item from the catalogue module of the automated library system. ------------------------------------------------------------------------ #### Withdrawing items Although the basic deletion process is very simple, there may be complications. The system may require a special procedure if it is the last remaining copy of a book, or if it is an item forming part of a special collection. Clearly your library will have its unique rules for this type of matter. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.7 Ascertain the policy in your library if an item being withdrawn is shown to be the last copy of this title held within the library service. ------------------------------------------------------------------------ #### Adding items You also need to understand how resources are added to the catalogue. In some library services, library staff undertake much of the work related to cataloguing and classifying items to be added to stock. In many other services this is done automatically using records from the supplier or downloaded from elsewhere during the order process. However, even here, with certain items, such as donations to the library, it may be necessary to create a new record and enter all its data manually. \-\-\-- ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.8 Note down the procedure to manually add an item to the catalogue module of the automated library system. ------------------------------------------------------------------------ Of course, having found the item after successfully searching the catalogue depends on knowing the layout and organisation of the particular library. The catalogue entry will include a shelf mark. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, note down how fiction items are arranged in your library. ------------------------------------------------------------------------ #### Shelving items Fiction is usually arranged by author surname in alphabetical order. Then, within any one author, by title. Where no author exists, the editor\'s surname or title is used alphabetically. A popular method of shelving fiction is by the use of genres. Essentially a set of genres are decided upon, e.g.: crime, fantasy, science fiction, romance and the books are labelled correspondingly and placed on the shelves in their appropriate genre. The catalogue entry will indicate this. Non-fiction is usually shelved by subject according to the local classification system. Here too genres may be used, e.g.: libraries frequently group all biographies together. Whichever methods are used, stock items are always organised according to agreed principles by libraries in order to aid the swift retrieval of resources either physically from the shelved collection or virtually from the library catalogue. ### Inter Library Loan module You should be familiar with the steps associated with the ILL process. It may be that the borrower has a specific item in mind, in which case you must get a precise description of the item. What information about a book would you ideally wish to have before placing an ILL request? To satisfy the British Library ILL form, a considerable amount of information is required, indeed the full bibliographic details. In the case of a book, these are the following: - Author - Title - Year of publication - Edition - ISBN - Publisher & place of publication - The source of the reference And remember you also need to record the name and contact details of the borrower. If, as is likely, the borrower cannot supply you with full bibliographic details of the item being requested, you will need to ascertain these using appropriate bibliographic tools. It may be that from the nature of the borrower request (they cannot find an item to satisfy their quest) you may need to follow the reference interview process, described in Unit 1 so that you have a clear definition of the subject area required by the borrower. #### Inter Library Loan procedures Before embarking on the ILL procedure, it is always worth double-checking your own library catalogue to verify that the requested item is not actually in your stock. If it is not, your library service will have procurement procedures and appropriate ways of securing the item. For example, this might be purchasing the item, instigating an internal ILL or carrying out an external ILL. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.9 Check out your library authority\'s procurement procedures for securing an item which might be subject to an ILL. ------------------------------------------------------------------------ Let us assume that an ILL will be required. The automated library system will allow the following steps to be carried out: - The initiation of an ILL request - Tracking the progress of an ILL request - Informing the borrower of the arrival of an inter-loaned item - Issuing the inter-loaned item - Discharging the inter-loaned item - Recalling an inter-loaned item - Recording the return of an inter-loaned item to its home library #### Using Inter Library Loans You should be familiar with all aspects of the Inter Library Loan system in use at your own location. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.10 Make yourself familiar with the Inter Library Loan module of your automated library management system for: - Initiating an ILL request - Monitoring progress of an ILL request - Carrying out internal ILL procedures for issue, discharge, recall of ILL items to client - Carrying out procedures for receipt of and return of ILL item from/to home library. ------------------------------------------------------------------------ You will find that the rules governing the use of ILL items will vary from those for stock items found in your own library. It is important to be aware of these conditions and to be able to explain them to the borrower. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, jot down some points which you think might be different for ILL items. ------------------------------------------------------------------------ #### Rules governing Inter Library Loans Three important points are as follows: Costs: your library may make a charge, thus passing on some of the ILL cost to the borrower, e.g.: fines for late return - there are additional penalties for non-return of British Library items within loan period. Timescales: you will need to give as accurate as possible an estimate of the time taken to secure the item. Also the period of time that the borrower can hold the item may be different from the loan period for similar items in your own library stock. Restrictions on use: it may be that the item may only be consulted within your library and not borrowed. There may be photocopying restrictions on the item. ## Use ICT sources in stock selection ### Criteria for stock selection Although you may not be responsible for the selection and acquisition of materials for your library, you may contribute to the identification of appropriate materials for the service. You certainly need to understand the principles of stock selection for public libraries. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, jot down the information you think you would need to make decisions on which stock to purchase. ------------------------------------------------------------------------ #### Selecting stock The two main drivers in stock selection are the current demands of the borrowers and the current stock available. The current demand has to be audited. This is relatively simple when an automated library system is being used. In fact, it is possible to be overwhelmed by the available statistics from an automated system. So a careful approach is required in deciding which categories, fiction genres and authors to run statistics on. This information on borrowing can be compared with the current stock provision. Broadly speaking there should be a match between the two. Thus looking at the detective genre, if the books by two popular authors show a great disparity such that the books by author X are on loan five times as much as author Y, there may be a good case for purchasing more copies of the books by author X. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, think of circumstances where this may not be valid ------------------------------------------------------------------------ #### Factors affecting demand It would be important to take into account any reading promotions carried out by the library on author X. Another factor might be that author Y\'s books are shelved in an inaccessible place. Perhaps X\'s books are paperback and Y\'s are hardback and your borrowers prefer the paperback format. The conclusions on the previous page are made under the assumption that the stock levels, display methods and format are roughly the same for both authors You also need to be aware of reading promotions external to your library which might drive a boom in borrowing books by author X. Although it may still be valid to increase your stock because there is a genuine and sustainable increase in interest in reading author X as a result of rave reviews on a television arts programme, you do need to question the sustainability. You do not want to be left six months later with a shelf full of author X\'s books which are no longer being borrowed. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, think of other reasons for choosing items for stock apart from balancing stock and demand. ------------------------------------------------------------------------ #### Additional criteria for stock selection Apart from this balancing of stock and demand, we think that the following points will drive stock choice. Gaps in stock which need to be filled. Obvious examples are new novels by favourite authors, or earlier novels which have never been in the stock of the library. There will also be a need for replacement copies due to poor condition or because material is out of date in the case of reference items for instance. There will also be some form of stock development plan for your library. This may cover the need for more diverse formats, including non-book resources, as well as new directions of book materials. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.1 Note down the stock development plans for your library. If necessary ask other library colleagues. ------------------------------------------------------------------------ All the above points go to making up the stock selection policy for your library. From this policy, it is possible to identify criteria for selection of new stock items. It is now possible to use online selection tools to find possible new items and assess them against the agreed stock selection criteria. ### Online library catalogues Of the possible ways of finding suitable material for stock selection, the use of online library catalogues of other libraries has the advantage that the materials ought to be properly catalogued and so easy to find using keywords. QUESTION TextEntry1: Online library catalogues This ability to search other library\'s catalogues is increasingly possible because it is becoming commonplace for libraries to have catalogues which can be searched via the Internet. The UK Public Libraries Page is a useful resource, linking to the web-available catalogues. <http://dspace.dial.pipex.com/town/square/ac940/weblibs.html> Some services combine together the catalogues of several libraries. A single-search interface is used to cross-search multiple catalogues in a single search action. In Wales there is CatCymru which enables the searching of library catalogues across all public, FE and HE libraries in Wales ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.2 Go to the UK Public Libraries Page and find examples of public library services with combined catalogues. (There are several examples of this.) ------------------------------------------------------------------------ #### Combined catalogues Some websites combine catalogues of collections with a common theme. Here are some more examples of catalogues to explore: - British Library <http://catalogue.bl.uk> - Northern Ireland <http://www.ni-libraries.net/library-card/library-catalogue/> - CatCymru <http://library.wales.org/catcymru/> - Birmingham <http://www.birmingham.gov.uk/libcat> #### Differences between catalogues The catalogues we looked at on the previous page vary in the details they provide and in the range of functions which can be performed. They do however offer the opportunity to trace resources. Here you are using the existing systems for inter-library loan as a helpful way of allowing library staff to view each other\'s collections. Some services may have automatic links to bibliographic service providers such as Talis or subscriptions to services such as Whittaker\'s Books in Print. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.3 Go to the Northern Ireland catalogue <https://opac.librariesni.org.uk/> and search under author for Dan Brown\'s "The Da Vinci Code". Look through the list and select the correct author. Follow the links and note that you can clearly see format, availability and reserve the item online. Compare this to the information available for the same book from your service. ------------------------------------------------------------------------ QUESTION TextEntry1: ### Publishers' and booksellers' websites The most obvious place on the Internet to look for new stock items is of course the library booksellers' and publishers' websites. These companies aim to sell the items and so one would expect that they contain the most up to date information on things like prices and publication dates for the items. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, think of other more negative points about the use of such websites. ------------------------------------------------------------------------ #### Negative aspects to commercial sites Well, you have to bear in mind that publishers and booksellers have a commercial imperative and thus the content may be biased or might not provide full information. You must exercise caution when using these websites to select material and you must therefore ensure that any selected materials do properly match the agreed selection criteria. #### Example sites Here is a small selection of useful sites: - Askews <http://www.askews.co.uk/site/default_askews.asp> - Bertram Library services <http://libraryservices.bertrams.com/BertramLibraryServices/> - Booksellers Association <http://www.booksellers.org.uk/> - Scottish Bibliographies Online <http://www.scotlandsculture.org/sbo/sbo.htm> - Welsh Books Council <http://www.cllc.org.uk/> - Books from Scotland <http://www.booksfromscotland.com> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.4 Go to the Harper Collins website (http://www.harpercollins.com) and follow links from the home page to New Releases, Forthcoming Titles and Best Sellers. Look for a favourite author in these sections and note the information you can find about the author, forthcoming events, full list of titles in print, range of formats titles are available in and links to author\'s websites. NB: You can also register for an author tracker facility and to find out about new writing. ------------------------------------------------------------------------ #### Services offered Some of the websites offer a range of sophisticated services -- pre-publication ordering facilities, EDI (Electronic Data Interchange) information, download facilities of MARC (Machine Reading Catalogue) records and tracking systems for current orders. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.4 Choose one of your own library suppliers, view their website and make a note of the services apart from straight forward sale of items which they provide. Find out how well they integrate with your automated library management system. You may find it useful to ask your colleagues about this. ------------------------------------------------------------------------ ### Online reviews and personal evaluations The Internet provides a great potential for reviewing potential new stock items. There are many websites which will provide this sort of service. An obvious choice is the bookseller Amazon However, there are many others' including sites linked to newspapers. Here are some examples: - The Guardian book review site <http://books.guardian.co.uk/reviews/> - The Independent book review site <http://www.independent.co.uk/arts-entertainment/books/reviews/> ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, think of more negative points about the use of such websites. ------------------------------------------------------------------------ #### Negative aspects of online reviews You have to treat reviews which have been posted on the Internet with some caution. They often include only part of the entire review and the views of the individual reviewer are unlikely to have been through a rigorous editorial process, unlike print journals. It is also possible to review extracts of audio/visual materials using the Internet, again candidates should return to the stock selection policy for guidance prior to purchase. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.4 Go to the Guardian\'s website <http://books.guardian.co.uk/reviews/> and compare one of the reviews with the book blurb on the publisher\'s website or another review on the same title. Look at style, content, detail and overall conclusion of the reviews with a view to their helpfulness within stock selection. ------------------------------------------------------------------------ ## Use ICT in continuing library practice and professional development ### Discussion lists Online discussion lists (sometimes called groups, newsgroups or forums) are the Internet version of electronic bulletin boards, popular among computer users long before Internet. A user can post comments on a topic and other users can respond. Messages are visible to all members of the group and some services provide extensions such as file storage and calendaring. The original newsgroup service, Usenet, is now available via Google Groups (http://groups.google.co.uk). Other services include Jiglu (http://www.jiglu.com/) and Yahoo Groups (http://groups.yahoo.com). Discussion lists are a useful tool for both individual professional development and solving specific problems. Lists work in the following way. You have to sign up as a member, giving your e-mail address. Any of the members can send in an e-mail with information of interest to the group or a question. All these e-mails are forwarded automatically to all list members. This usually generates a flurry of helpful responses. Some lists are moderated so that the e-mails are only posted after they have been vetted. For the lists you use, you should be aware which are vetted and which allow e-mails to be sent instantaneously. We can classify discussion lists into three broad categories: - professional discussion lists run by or for the professional library bodies - government or local government sponsored lists - ad hoc lists run by interested people or groups. #### Professional discussion lists JISC mail (the service provided by the Joint Information Systems Committee) is one of the key providers of discussion lists and has a number of public library, special interest and library profession groups. The home page is <http://www.jiscmail.ac.uk/>. You can search for different lists based on topic and there are many related to libraries. You can see a list of library categories on this page: <http://www.jiscmail.ac.uk/mailinglists/category/Library.html> Three specific examples of lists which can be used for professional matters by library staff are: - LIS-PUB-LIBS: is a forum for discussion of issues relating to UK public libraries. See the joining page at: <http://www.jiscmail.ac.uk/cgi-bin/webadmin?A0=lis-pub-libs> - LIS-SCOTLAND: is a forum for discussion of issues relating to Scotland. See the joining page at: <http://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=lis-scotland&A=1> - LIS-Wales: is a forum for discussion of issues relating to Wales. See the joining page at: <https://www.jiscmail.ac.uk/cgi-bin/webadmin?A0=lis-wales> CILIP has a range of professional discussion lists which are targeted at supporting members of library staff who share particular professional interests or working environments. Visit <http://www.jiscmail.ac.uk/mailinglists/category/Library.html> to browse the library discussion lists (you can search for the CILIP sponsored discussion lists using \'LIS-CILIP\'). ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.1 Select an appropriate online discussion group on a subject that interests you e.g. information literacy, youth library work or mentoring. Join a group (you will find more at <http://www.jiscmail.ac.uk/mailinglists>) and read some of the recent discussions. ------------------------------------------------------------------------ #### Government sponsored lists Non-library-specific discussion groups, such as those run on local authority websites or the websites of other agencies may also be useful. An example is the Welsh Assembly Government which offers a range of consultation and discussion forums (you have to register to access the forums): <http://wales.gov.uk/?lang=en> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.2 Search the Internet for a discussion list for your geographic area, perhaps run by your local authority. ------------------------------------------------------------------------ #### Ad hoc groups and lists There is a range of commercial service providers such as: - Yahoo Groups <http://uk.groups.yahoo.com/> - Jiglu <http://www.jiglu.com/> - Freeboards <http://www.freeboards.net/main.htm> They provide discussion groups (lists) free of charge. These offer simple, alternative ways to start discussion lists for groups, e.g. Community Services Group (Scotland) at: <http://groups.yahoo.com/group/csgscotland/> Of course this also means that you can also easily set up a group to discuss any topic you choose. This approach can allow you to share ideas in the professional field. Social networking websites have a huge potential for useful exchanges of news, information and ideas. Many of them have established areas for library interests. The main problems are the quality of the content and access from within local authority firewalls. Here are some sites to look at, if you can access them. - CILIPS <https://twitter.com/CILIPScotland> - CILIP South East Branch Flickr <http://www.flickr.com/photos/cilip-se/> - CILIP Career Development Group Facebook <http://www.facebook.com/group.php?gid=2421438148> - Welsh libraries blog <http://libalyson.wordpress.com/> - Del-i-cious - Scottish libraries blog <http://scottishlibraries.wordpress.com/> - Scottish Library and Information Council <http://www.scottishlibraries.org/> which incorporates a range of web 2.0 tools. Guidance on using web 2.0 in a library and information service context have been published and are interesting reading. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.3 Taking any one of the three group providers mentioned above, explore how to set up a group for your own use.For all three use the group index or search system to find groups related to library work. ------------------------------------------------------------------------ ### Professional websites You should be familiar with and able to access a range of key professional websites to support you in your professional practice. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, jot down any websites you can think of which fall into the above category. ------------------------------------------------------------------------ #### Types of professional website The websites you have listed are likely to fall into one of three categories: - Websites of the strategic agencies - Websites of professional associations and special interest groups - Websites of local agencies #### Websites of the strategic agencies Each of the 4 UK home nations has its own strategic agency for libraries. These are: - Arts Council England <http://www.artscouncil.org.uk/what-we-do/supporting-libraries/> - Scottish Library and Information Council (SLIC) <http://www.scottishlibraries.org/> - Museums Archives and Libraries Wales (CyMAL) <http://www.cymal.wales.gov.uk/> - Library and Information Services Council (Northern Ireland) LISC(NI) <http://www.liscni.co.uk/> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.4 Look at each of these 4 websites and compare the information given. ------------------------------------------------------------------------ #### Websites of professional associations and special interest groups All professional associations have websites. These usually comprise pages which can be accessed by anyone plus further sections which are available only to members who use a password to access them. The main professional association in the library field is the Chartered Institute of Library and Information Professionals (CILIP) at: <http://www.cilip.org.uk/> Many relevant special interest groups have websites. These can be particularly useful as they often act as portal sites, collecting links to other websites based on the same or similar topics. Examples are: - CILIP Multimedia Information and Technology Group <http://mmitblog.wordpress.com/> - The Historic Libraries Forum <http://www.historiclibrariesforum.org.uk/> - International Association of Music Libraries, Archives and Documentation Centres <http://www.iaml-uk-irl.org/> #### Websites of local agencies You should also be aware of the importance of the contents and functions of your own local authority website and local intranet. Simple client enquiries made at the library counter or over the telephone can often be answered from these sources and it is useful to be well informed regarding content and layout so that site navigation takes the minimum amount of time. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.5 Spend some time making yourself familiar with the website run by your own local authority. ------------------------------------------------------------------------ ### Online professional journals Online journals offer a readily accessible and searchable source of professional information. Some are freely available but others operate on a subscription basis. Examples are: - CILIP Update <http://www.cilip.org.uk/publications/updatemagazine> - CILIP in Scotland <http://www.cilips.org.uk/> - Journal of Information Literacy <http://ojs.lboro.ac.uk/ojs/index.php/JIL> CILIP members enjoy free online access to the Journal of Information Science and Journal of Librarianship and Information Science from the CILIP website. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.6 Look at the latest issue of CILIP Update at <http://www.cilip.org.uk/publications/updatemagazine> Familiarise yourself with the layout and content. Is there anything in this issue which is of interest to you in your current job role? ------------------------------------------------------------------------ You should get into the habit of regularly checking on-line journals to gather information and ideas which are relevant to your own continuing professional development.
# Applications of ICT in Libraries/Safe and Legal Use of ICT This page is designed for the use of students undertaking the Diploma (Diploma ICTL) or the Advanced Diploma (Advanced Diploma ICTL) in Applications of ICT in Libraries. \-\-\--CHANGES TO THE QUALIFICATION\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-- The Diploma and Advanced Diploma have been superceded by the Professional Development Award in Applications of ICT in Libraries at levels 7 and 8 (English and Welsh levels 4 and 5). They consist of much the same content as the Diploma and Advanced Diploma but the PDAs include two new Digital Culture units. ------------------------------------------------------------------------ These qualifications were developed by the Scottish Library and Information Council (SLIC) and are validated by the Scottish Qualifications Authority (SQA) Supporting Clients in the Safe and Legal Use of ICT is a Mandatory unit in the level 7 programmes. Information regarding the background to the courses, content and certification opportunities can be obtained by following the Diploma (Diploma ICTL) or the Advanced Diploma (Advanced Diploma ICTL) links. ## Safe practice relating to the use of ICT for communication ### Using ICT for communication This section relates to supporting clients in using ICT safely for communication purposes, within the constraints of current legislation. Clients should already possess basic ICT skills, such as simple word processing and the ability to navigate the Internet using a web browser. You should also establish the client's communication needs, e.g. do they need e-mail for personal or work-related correspondence, in order to assist in the selection of a suitable e-mail service. The use of e-mail exploded some years ago, encouraged by the fall in prices of home PCs and the introduction of free Internet access in libraries and schools. Since then despite the rise of social media email use has continued to increase and is predicted to continue. Email is an essential method of communication both socially, commercially and professionally. There are many advantages: - the speed of delivery - the ability to send to multiple recipients - the flexibility of using web-based e-mail accounts for sending e-mails for various locations - the ability to attach other types of files, such as images. - the low cost involved in sending mail in bulk. #### Electronic mail You should have an in-depth knowledge of electronic mail including: - local e-mail software, systems and protocols - the structure of e-mail addresses - tracking e-mail messages - delivered, read etc. - using importance flags - changing setting for preferred presentation Yo may be asked to set up e-mail accounts for clients ... #### Setting up e-mail accounts A web-based e-mail account is one where the user accesses his or her e-mail by means of a web-browser, such as Internet Explorer or Firefox, rather than by using a specialist e-mail client program, such as Outlook, Outlook Express or Thunderbird. You should be able to set up web based e-mail accounts and to show clients how to do this. This includes opening and closing the account. #### Free e-mail services Popular free e-mail services include the following: - Gmail <http://www.gmail.com> - Hotmail <http://www.hotmail.co.uk> - Lycos <http://mail.lycos.com/lycos/Index.lycos> - Yahoo <http://mail.yahoo.com/> - Mail2web <http://mail2web.com/> For some tips on email providers and the pros and cons associated with each one have a look at this link <http://www.pcadvisor.co.uk/features/internet/3448241/whats-best-free-email-service/> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.1 If you are not already familiar with the process, log on to one of the e-mail services above and follow the instructions to create an account for yourself, e.g.: joe_bloggs@hotmail.co.uk. As you do this, note down any points which you would wish to make to clients when demonstrating how to set up an email account. You will use this account or one of your own existing ones in subsequent activities. ------------------------------------------------------------------------ #### Sending and receiving e-mails Using e-mail is a big step for the uninitiated and assumptions should not be made about how quickly clients can absorb technical details and instructions. If you are in any doubt, you can find out how to send and receive mail from the help pages of the relevant e-mail services. You'll usually find a link to this on the opening page of any web based e-mail service. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.2 Select one of the web-based e-mail services listed above and show a client how to carry out the following tasks: 1\. create a new e-mail 2\. add content to an e-mail 3\. send an e-mail to a recipient 4\. check for new e-mails sent to them 5\. open received e-mails 6\. reply to e-mails received 7\. forward a received e-mail to another recipient. If you send e-mails to one of the accounts you created earlier, you'll be able to check that they've been received correctly and demonstrate this to the client. ------------------------------------------------------------------------ Once your clients have mastered the basics of e-mail, they'll probably want to move on to more complex tasks. Let's start by looking at sending, receiving and saving attached files ... #### Using attached files One of the particularly useful things about e-mail is the ability to attach files and thus send, say, copies of photographs to the recipient. This is particularly useful for older clients staying in touch with their family when they stay at a distance. Any sort of file can be attached and sent with an e-mail. Another common file type attached to e-mails is a word processed document You should be able to show clients how to attach files. The client may create the file in the library, e.g.: by typing a Word document or scanning in a photograph. Clients may also wish to attach previously created files brought to the library on floppy disks, CDs or USB flash drives. Not all library authorities allow the use of removable data, so you should check this for your own library service. One area where clients may run into difficulties involves the size of attached files #### Size of attached files You should make the clients aware of possible limits to the size of files attached to e-mails. There are two points. Firstly some web-based free e-mail services do not allow particularly large attachments. The second point is that, if the recipient is on a dial-up connection, large attachments may be almost impossible to download. This is a particular problem with photographs which can often be several megabytes in size. You should explain the idea of possibly resizing photographs and definitely compressing them. A rough guide might be that unless there is a special reason, attached photographs should be no more than say 100K in size. To resize a photograph, the client needs access to image processing software. A free example may be found in Irfan View On the other hand many e-mail programs offer automatic compression of photographs. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.3 Using one of the e-mail programs listed above, demonstrate to a client how to send both a word-processed document and a photograph as attached files. If you send e-mails to one of the accounts you created earlier, you'll be able to check that they've been received correctly and demonstrate this to the client. ------------------------------------------------------------------------ #### Using zipped files With e-mail attachments such as large graphics or word processed documents a reduction in size is achieved by compressing or "zipping" the file. If you are using certain operating systems, for example most versions of Linux and Windows ME/2000, file zipping is built in to the operating system. If you are using an earlier version of your operating system, you may need to install a third-party program such as WinZip. You can download an evaluation copy from <http://www.winzip.com> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.4 Using one of the e-mail programs listed above, demonstrate to a client how to compress or "zip" documents and attach them to an e-mail. If you send e-mails to one of the accounts you created earlier, you'll be able to check that they've been received correctly and demonstrate this to the client. You should also show the client how to decompress or "unzip" files and save or print them. ------------------------------------------------------------------------ Another area your clients will need to know about is virus checking #### Virus checking Viruses in e-mail attachments may cause serious problems for users. Local authorities have anti-virus software in place but you should be aware that this can be a serious problem for home users. Clients can inadvertently pick up viruses and then transfer them between machines when they use files on public access PCs. Automatic checking should be in place but you should still advise clients not to open unrecognised e-mail messages or attachments. Anti virus facilities, and the degree to which they can be automated, vary between e-mail service providers. You can find out how to configure anti-virus facilities from the help pages of the relevant e-mail services, which you can access from the opening pages. It might be worth noting that several providers limit sending or receiving of certain attachments (such as .exe, .bat or .com which are all Windows executables) - this can be useful in preventing the spread of viruses but it might hinder you should you wish to send such files legitimately over the system. #### Implementing virus checking Now try some activities relating to implementing anti-virus software. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.5 Go to the Lycos web-mail site at <http://mail.lycos.com/lycos/Index.lycos> and find out which type of virus protection is implemented. Alternatively, try searching for any email providers anti virus protection. e.g. type gmail virus protection into Google. ------------------------------------------------------------------------ In order to show clients how to check that the virus checking is turned on in their web-based e-mail service, you must be familiar with this facility in the commonly used services. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.6 Log on to any of the new e-mail accounts you created in the first exercise and make sure that automatic virus checking is turned on, as far as permitted by the e-mail service provider. ------------------------------------------------------------------------ #### Anti-virus software It is also worth informing clients about general antivirus software, which will protect against viruses from any source not just e-mails e.g. files brought in by a client on a floppy disk. AVG is a free anti-virus program which can be downloaded from <http://www.grisoft.com> Evaluation versions of subscription anti-virus programs can often be found on computer magazine cover CDs or they can be downloaded from: - McAfee <http://download.mcafee.com/us/eval/evaluate2.asp> - Norton <http://www.symantecstore.com> - Panda <http://www.pandasoftware.com/download/> Once clients start to build up a collection of sent and received e-mails, they may need to learn how to manage them so that they can be located easily when required, so let's have a look at Managing e-mails ... #### Managing e-mails The key to effective management of e-mails is always to have an almost empty in-box. In other words, when you receive e-mails you should be able to deal with them promptly and either delete them afterwards or store them in other folders which you have prepared in your e-mail program. You have to show your clients how to do this with their web-based e-mail account. We suggest that you spend a little time with the client, getting an idea of the likely categories for their e-mails, setting up one folder for them and then allowing the client to do this for themselves for the other categories. Google mail (Gmail) utilises Labels rather than folders. Labels work in a similar way but can take some getting used to especially as emails can be given more than one label. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, think of a typical client and jot down a list of folder names which might accommodate the majority of their e-mails. ------------------------------------------------------------------------ #### E-mail folders We can think of the following: - Family members - Friends - On-line shopping - Holidays You may also have thought of others. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.7 Using one of your web-based e-mail accounts, set up folders for the four categories we have listed above. Note down any specific points you would want to alert a client to when demonstrating this procedure to them. ------------------------------------------------------------------------ As well as trying to prevent viruses, clients will also need to take steps to protect themselves against other online threats and nuisances. Let's take a look at Combating spam ... #### Combating Spam All e-mail accounts are bombarded to a greater or lesser extent by unsolicited e-mails sent out by hoaxers or commercial interests. These e-mails are known as "spam". In some cases clients will find the spam e-mail subject as well as the content offensive. Most software systems and web based providers offer processes which can block a large percentage of unsolicited mail. You should make clients aware that accessing some websites and responding to messages where they are required to type in their e-mail address may aggravate the problem by signing them up to more junk mail. This is a particular problem with unsolicited e-mails which have a link purporting to remove you from the mailing list but in fact confirms that the account is active and will result in more spam. The spam filtering systems used by web based e-mail providers suffer from the same flaw that all spam filtering exhibits -- sometimes, genuine wanted e-mail gets classified as spam and does not appear in the in-box. You can find out how to manage combat spam from the help pages of the relevant e-mail services. You'll usually find a link to this on the opening page of the service. A good suggestion is to have two email accounts, one for personal emailing and another for use when purchasing online. Online shopping is a common way for spammers to find email addresses to pester! ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.8 Log on to each of the new e-mail accounts you created in the first exercise and make sure that the spam filters are turned on. ------------------------------------------------------------------------ #### E-mail etiquette The term "netiquette" is used to describe the rules that govern polite use of the Internet when interacting with other users. Clearly, a large part of this centres round the use of e-mails. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, jot down any points you can think of relating to courteous and effective use of e-mail. ------------------------------------------------------------------------ #### Netiquette Simple points of e-mail netiquette are: - properly describing the purpose of the e-mail in the subject field - using spell checking - avoid using solely capital letters. Using capital letters in an e-mail is seen as the equivalent of shouting at someone. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.9 Look at the exhaustive set of e-mail etiquette rules at <http://www.emailreplies.com> and make a list of the most obvious ones which you can then demonstrate to clients using e-mail in the library. ------------------------------------------------------------------------ Clients may also want so send e-mail to news groups, so we'll look briefly at Using news groups #### Using news groups When using news groups there is a protocol in replying to the various discussions/threads: - make sure that you are using the correct news group - make sure that you really mean to reply to the whole group and not just send a personal message to an individual member - always reply to the correct thread - sending the same message to several groups (cross posting) is frowned upon. Clients should be warned that they should always think very carefully before posting a message to a public newsgroup. There are group archives (e.g.: <http://groups.google.com>) which store every message ever posted, so a message can have a potential lifespan of many years and could be seen by millions of people! Once a message is posted there is no way of retracting it. Sometimes clients will want to send an e-mail to several people at the same time, so we'll look next at Sending e-mail to multiple recipients... #### E-mailing multiple recipients One of the time-saving features of using e-mail is to be able to send the same information to several people with little more effort that sending to only one recipient. This, of course, is the reason for the existence of spam. You should be able to show clients how send e-mail to multiple recipients, including replying to all, adding additional recipients and forwarding files. They should know how to send e-mails to multiple recipients without displaying the e-mail addresses of all recipients, a facility often known as blind carbon copies (Bcc:). This last point is important netiquette as it is very impolite to broadcast the e-mail addresses of others without their permission. You can find out how to send e-mail to multiple recipients from the help pages of the relevant e-mail services. You'll find a link to this on the opening page of the service. A more efficient way of emailing multiple recipients is to create groups. The benefit of using groups is that once created you just type the group name and the email will go to everyone in the group AND you will never miss anyone (as long as you created the group correctly in the first plaace!) ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.10 Log on to one of the new e-mail accounts you created in the first exercise and send an e-mail message to multiple recipients, i.e.: send the message to Account No 2, copy it to Account 3 and blind copy it to Account 4. Log on to the three recipient accounts and check that the messages have been received correctly. ------------------------------------------------------------------------ Sometimes clients will reach the stage where an e-mail account is no longer required, so we'll take a look now at Closing an e-mail account #### Closing an e-mail account You should warn clients that most web-based free e-mail accounts expire if not accessed by the user for a specified period of time, sometimes as short as 30 days. In this way the e-mail account will close itself. However, it is netiquette that e-mail accounts should be closed when they are no longer required. This avoids the problem of people sending e-mails to what appears to be a valid address, when no-one is checking the account. You can find out how to close an e-mail account from the help pages of the relevant e-mail services. You'll find a link to this on the opening page of the service. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.11 Log on to each of the four e-mail accounts you created in the first exercise and close each of them. (Assuming you no longer want to use them). ------------------------------------------------------------------------ Clients will often want to use Internet facilities other than e-mail, so we'll look next at Using chat rooms #### Using chat rooms Chat rooms are virtual social spaces on the Internet, where users can communicate with each other. Chat rooms are extremely popular because of their unedited and instantaneous nature. Some chat rooms are used simply for entertainment purposes, perhaps based around a topic such as discussing a daily television soap opera. Others may be used for more serious discussions. As with most of the Internet, younger clients are often very savvy with the technology and are keen on using chat rooms to communicate with others of the same age and with similar interests. It is easy to see the attraction for young people of being able to access this 'secret' world of anonymous communication where their parents cannot see what they are doing and in principle no holds are barred regarding 'bad' language. You should be able to inform clients about Acceptable practice in chat rooms Chat rooms have largely been superceded by other social networking services (Facebook, Twitter and Google hangouts etc) but they are still a feature of many peoples online lives. #### Acceptable practice in chat rooms There has been increasing concern about the use of chat rooms for "grooming". "Grooming" is the term given to interaction between an adult and a child with an end view of sexualising that relationship. "Grooming" is illegal. You need to advise younger clients as to how they can keep themselves safe by keeping personal information to themselves and never agreeing to meet alone in person anyone they have a chat room-friendship with. They should report any unwanted attention to their parents and / or the chatroom owners. You must make adult users of chat rooms aware of what is acceptable when they are using computers in the library -- this may be more restrictive than when using home PCs. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.12 Find out your library authority's policy and procedures regarding acceptable use of chat rooms and safeguarding young clients. ------------------------------------------------------------------------ #### More about chat rooms You can find useful information on this, and other topics at: <http://publib.boulder.ibm.com/infocenter/sametime/v8r0/index.jsp?topic=/com.ibm.collaboration.realtime.help_80/c_stadv_uim_whatis_chatrooms.html> You can find Chat services at: - Lycos Chat <http://chat.lycos.co.uk/> - Social networking websites Social networking websites and Chat rooms share similar concerns about safety and vulnerable groups. Social networking websites are very popular because they bring together friends and friends of friends who share a common interest. The illusion that it is a community of friends sometimes means that natural caution is abandoned and private details are shared. In many local authorities and organizations access to social networking websites are blocked by firewalls. These website can offer valuable professional tools and there are some examples of these in Unit 4. Examples of social networking websites include - Bebo www.bebo.com - Facebook www.facebook.com - Flickr www.flickr.com - LinkedIn www.linkedin.com - MySpace www.myspace.com - Tumblr www.tumblr.com - Twitter <http://twitter.com> - WindowsLive www.home.live.com The ICTL units Digital Culture: Online Communication and Digital Culture: Online Collaboration cover social networking in far greater depth. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.13 Log on to the Lycos chat service listed above and see if you can find a chat room where readers discuss books they have read. Check the Help pages for full details of how to use the service. OR try using a search engine and type \"book reading chat room\" one example is <https://bookclubreading.com/chat-rooms/> Clients may experience difficulties in carrying out certain tasks due to security restrictions placed on servers, so let's take a look at Secure servers ------------------------------------------------------------------------ #### Secure servers Local authorities normally have secure servers to protect the local authority and public from potentially hostile breaches. This means that desktops are often "locked-down" and you cannot make changes to the settings on PCs in your library. This can be frustrating -- especially when simple changes to the resolution of display, for example, would be useful for visually impaired clients. Secure servers also have restrictions on adding new software or on downloading executable files. It may also be worth pointing out to library clients the importance of checking the security of the sites they use when making purchases online. Vendors should always use secure servers for the parts of their systems where customers will be typing in personal and financial details, such as credit card numbers. There are two ways a client can check whether their details are secure: ⋅They should look for a closed padlock symbol, normally in the address window of the web site. ⋅They should check that the web address starts HTTPS. The S is the bit which tells them the server is secure. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.14 Check your authority's policy on secure servers and prepare a brief explanatory note for clients. ------------------------------------------------------------------------ Clients may wish to convert paper-based materials, such as photographs, to digital images so they can be sent as e-mail attachments, so let's have a look at Scanning images and saving to disk... #### Scanning and saving images Scanning of images and saving these to disk has increased with the proliferation of inexpensive scanning devices. Many clients will wish to send copies of photographs to their family via e-mail. You should be able to demonstrate to a client how to scan an image -- either of text or pictures - and save it to disk. (Note that the scanned files will often be large and may need to be reduced in size if they are to be attachments to e-mails.) Since there is such a range of types of scanner and associated software, we cannot realistically give instructions for use here. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.15 Practice using your locally-available scanner and software to scan and save both text and images. Find out how to reduce the resulting file by compressing it so that it will be acceptable as an e-mail attachment. Note down any points which you will want to make your clients aware of. ------------------------------------------------------------------------ ## Using ICT to support clients with special needs or specific language requirements Bear in mind the Equality Act <https://www.gov.uk/guidance/equality-act-2010-guidance> which encompasses the Disability Discrimination Act (DDA <https://www.nidirect.gov.uk/articles/disabled-peoples-rights-everyday-life>) ### Introduction This section relates to the ways in which ICT can support clients with special needs or those with specific language requirements. For example, this client group might include those visually impaired, those whose first language is not English, those disabled, those with literacy difficulties, and those with dyslexia or learning disabilities. Many of the clients in this group will be mature and capable with the same information needs as everyone else and could benefit from some of the assistive technologies to enable them to access the wide range of resources. Sensitivity is required in assessing the ability and aptitude of the client. It is important to remember that disabilities may not affect the reading level of clients or their interests. It may be useful to use pictograms instead of text in signage for some clients in this group. #### Websites for those with special needs or specific language requirements When dealing with clients having special needs or specific language requirements, special care should be given to the appropriateness of recommended websites. As well as the criteria applied to assessing the appropriateness of websites in general, you should exercise care to ensure that clients are directed towards accessible sites with appropriate content and format. For example, visually impaired people may be unable to access websites which are incompatible with software which they rely on. Clients with Impaired Vision Clients with impaired vision may be able to use a normal monitor screen if the settings are adjusted to give large font size and high contrast. However, others will need to use a software package which will read out the text on the web page -- a screen reader. Some web sites will not work well with a screen reader. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, can you think of features on a website page which would cause difficulties for a client with impaired vision using a screen reader? ------------------------------------------------------------------------ #### Problems for clients with impaired vision The main problems are caused by screens which have no text. If it is not possible to read meaningfully only the text on the website page, then the screen reader will not be successful. So the following are the problem areas: - Web pages which overly rely on graphics - Web pages which have graphics or photographs with no alternative text explanation - Web pages with text which is presented within a graphic - Web pages which use explanatory animations The worst offenders can be sites that start in Flash with no text option, so that the user gets no information from the screen reader and doesn't know if the site is open or not. #### Screen readers Some problems have been reported in using screen readers with early version of Adobe Acrobat, but these have been overcome in later versions. You can find more information about this at: <http://www.adobe.com> (type screen readers in the search window) A good example of a screen reader which is well liked by users is JAWS for Windows. You can find more information about it at: <http://www.freedomscientific.com/fs_products/JAWS_HQ.asp> Many libraries use Supernova, which incorporates a screen reader called HAL. Supernova also incorporates a very good monitor screen magnification element - so it can help partially sighted clients. You can get further information (and download an evaluation copy) from: <http://www.synapseadaptive.com/dolphin/> The Royal National Institute for the Blind (RNIB) site gives a useful list of access software at: <http://www.rnib.org.uk/professionals/softwareandtechnology/softwareaccesscentre/Pages/software_access_centre.aspx> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.1 To get a better feel for screen reader software and especially to assist those clients with visual impairment, visit the RNIB site mentioned above and follow the links to some of the sites listed. Download evaluation copies of a few of the software packages and try them out. ------------------------------------------------------------------------ #### Colour blindness Colour blindness is another factor which can affect a client's ability to use a website. There are software packages which: a\) permit a person who is not colour blind to view a web page as it would appear to a colour blind person. This can be a useful check for library staff before recommending a website. b\) Use image processing techniques to make web pages clearer for those with colour blindness. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.2 Go to <http://colorfilter.wickline.org/> and try the procedure on some webpages which you commonly use. How readable would they be to a client with colour blindness? An alternative colour blindness simulator just for images is <http://www.color-blindness.com/coblis-color-blindness-simulator/> The SLIC website (https://scottishlibraries.org/advice-guidance/the-six-steps-promise/) provides information on accessibility issues. ------------------------------------------------------------------------ #### Clients with specific language requirements When assisting clients with specific language requirements, it is worth turning to the Google search engine. This provides a useful set of language tools for finding information and/or websites in specific languages and for translating between a range of languages. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.3 Use the Google language tools to: a\) translate a favourite web page into another language; b\) translate a foreign-language web page into English. Another site which offers translation facilities for text and web pages is: <http://www.babelfish.com/> c\) Try the two tasks above using Babelfish as well. Which site do you think gives the best translations? d\) It\'s important to note that the translation might be a little rough around the edges. Try translating a simple phrase to another language, and then back into English. You might notice quite a change in the meaning of the phrase! ------------------------------------------------------------------------ ### Evaluating websites against best practice guidance Websites which can help assess the suitability of website material include: - Introduction to web accessibility <https://www.w3.org/WAI/intro/accessibility.php> - BBC Best Practice Guidance <http://www.bbc.co.uk/accessibility/best_practice/what_is.shtml> - World Wide Web 3 Consortium <http://www.w3.org/WAI/> - WAVE Web Accessibility Evaluation Tool <http://wave.webaim.org/> - SLIC <http://www.slainte.org.uk/accessandequity/equityindex.htm> Look at the World Wide Web 3 Consortium pages and find out exactly what Best Practice in terms of web accessibility means. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.4 Follow the link to WAVE given above and use the tool to check the accessibility of a few of your favourite websites. ------------------------------------------------------------------------ ### Assistive technologies Technology can help to balance the difficulties encountered by some client groups. For example, those with motor impairment can access PCs with the aid of a large track ball mouse, touch screens, adapted keyboards and special software. You can find a number of companies which specialise in supplying assistive technology equipment. An example is Inclusive Technology at: <http://www.inclusive.co.uk/>. They have an online catalogue which groups the various items in broad headings. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.5 Browse the Inclusive Technology catalogue. This will give you a good overview of what is available in hardware assistance. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.6 Find out what is available within your own library and library service which would support clients requiring assistive technology. Make a note on each item for future use. ------------------------------------------------------------------------ #### Assistive technologies for clients whose first language is not English You should also be able to use software or keyboard adaptations for people whose first language is not English. It is important for you to know about both what is available locally and organisations to whom clients can be referred. Adaptive furniture can be of great use to help clients. You can see an on-line catalogue on the website of Synapse Adaptive here: <http://www.synapseadaptive.com/> They cover many adaptive technologies but if you look for hardware and then ergonomics, you will find a number of desk and chair items. ### Changing software and keyboard settings Although assistive technologies are widely available, sometimes all that is required to improve access for a client is to change the keyboard or software settings. This can allow the enlargement of text, icons and the speed of a mouse click to the client's comfort. Windows offers a huge range of accessibility features, including adjusting Display Options, adjusting Mouse Options, adjusting Keyboard Options, adjusting Internet Options, adjusting Sounds and Audio Options, adjusting Taskbar and Menu Options, adjusting User Accounts Options, adjusting Speech Options, Utility Manager, On-Screen Keyboard, Narrator and Magnifier. The Microsoft website has details of these at: <http://www.microsoft.com/enable/> Windows has an accessibility wizard which can take the client through the various PC settings. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.7 If you are using Windows 8 visit <http://www.microsoft.com/enable/products/windows8/> for help. Try the features. If you have access to Windows XP you can use the Accessibility Wizard to explore the Accessibility features. You can start it by clicking on: Start \> All Programs \> Accessories \> Accessibility \> Accessibility Wizard OR Start \> Run type accwiz in the Open window. If you are using an earlier version of Windows, or another Operating System, check your local help files to find out what options are available. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.8 From the information sources above, or additionally from the AbilityNet MyWay site at: <http://www.abilitynet.org.uk/search/node/myway> make a note of the accessibility features you are likely to require to show to clients. Jot down the steps you have to carry out to implement them. ------------------------------------------------------------------------ ### Voice synthesis and voice recognition Voice synthesis software can be used as an alternative to keying in and outputting in text format. There are two types of software required for this. Voice recognition software allows a client via microphone to give spoken commands to the computer, to allow PC use without a keyboard. Voice output from the PC is achieved by software which reads out what is displayed on the screen. This is of great use to clients with vision problems. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.9 Find out which of these types of systems are available in your own library service. ------------------------------------------------------------------------ #### Voice synthesis and voice recognition products There are a number of products available for both voice synthesis and voice recognition, including Dragon Naturally Speaking, CoolSpeach and Microsoft Speech Server. You can find further information about one of the best known products at the following web site: - Dragon Naturally Speaking: <http://www.scansoft.com/naturallyspeaking/> There are of course many others Some operating system versions have voice synthesis built in. Again the AbilityNet MyWay site at: <http://www.abilitynet.org.uk/search/node/myway> has information on this topic Of course many people now use mobile devices to access information and people using iPods or devices running on the Android operating system have a built in Voice Commands (iPod voice Control, Android Voice Actions) functionality. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.10 Select a voice recognition package and a voice synthesis package available to your library service. In each case set up the package and get practice at using it. Jot down sufficient notes so that you can demonstrate it to a client in the future. ------------------------------------------------------------------------ ## Legislation relating to the use of ICT for storage, manipulation and access of information ### Introduction This section relates to legislation concerning the use of ICT for storage, manipulation and access of information. Government legislation has a significant impact on ICT in libraries and staff require a sound working knowledge to ensure that clients can use ICT safely and legally. ### General Data Protection Regulation #### Visit the Moodle section on GDPR for up to date information ### Data Protection Act This section has been superseded by the General Data Protection Regulation (GDPR). The Freedom Of Information section below is still valid though `<s>`{=html}The Data Protection Act 1998 applies across the UK and gives legal rights to individuals in respect of their personal data held by others. Libraries must ensure that the ways they process personal data of clients and staff, whether manually recorded or computerised, comply with the provisions of the Act. This is particularly relevant to client data stored in an automatic library management system. Such ICT based systems facilitate analysis of client data which would not be possible with manual systems.`</s>`{=html} The following information is extracted from the Data Protection Act Fact Sheet, which can be downloaded from the Information Commissioner's website at: <http://www.informationcommissioner.gov.uk/>. The Data Protection Act 1998 seeks to strike a balance between the rights of individuals and the sometimes competing interests of those with legitimate reasons for using personal information. We will look at the following useful sections: - The eight principles of good practice - The six conditions for fair data processing - Sensitive data - Rights under the Act - Criminal offences created by the Act - Unsolicited electronic communications - The role of the Information Commissioner's Office #### The eight principles of good practice Anyone processing personal information must comply with eight enforceable principles of good information handling practice. These say that data must be: - - 1\. fairly and lawfully processed - 2\. processed for limited purposes - 3\. adequate, relevant and not excessive - 4\. accurate and up to date - 5\. not kept longer than necessary - 6\. processed in accordance with the individual's rights - 7\. secure - 8\. not transferred to countries outside European Economic area unless country has adequate protection for the individual #### The six conditions for fair data processing At least one of the following conditions must be met for personal information to be considered fairly processed: - - 1\. the individual has consented to the processing - 2\. processing is necessary for the performance of a contract with the individual - 3\. processing is required under a legal obligation (other than one imposed by the contract) - 4\. processing is necessary to protect the vital interests of the individual - 5\. processing is necessary to carry out public functions, e.g. administration of justice - 6\. processing is necessary in order to pursue the legitimate interests of the data controller or third parties (unless it could unjustifiably prejudice the interests of the individual) #### Sensitive data Specific provision is made under the Act for processing sensitive personal information. This includes racial or ethnic origin, political opinions, religious or other beliefs, trade union membership, physical or mental health condition, sex life, criminal proceedings or convictions. For personal information to be considered fairly processed, at least one of several extra conditions must be met. These include: - Having the explicit consent of the individual - Being required by law to process the information for employment purposes - Needing to process the information in order to protect the vital interests of the individual or another person - Dealing with the administration of justice or legal proceedings #### Rights under the Act There are seven rights under the Data Protection Act. - 1\. The right to subject access: This allows people to find out what information is held about them on computer and within some manual records. - 2\. The right to prevent processing: Anyone can ask a data controller not to process information relating to him or her that causes substantial unwarranted damage or distress to them or anyone else. - 3\. The right to prevent processing for direct marketing: Anyone can ask a data controller not to process information relating to him or her for direct marketing purposes. - 4\. Rights in relation to automated decision-taking: Individuals have a right to object to decisions made only by automatic means e.g. there is no human involvement. - 5\. The right to compensation: An individual can claim compensation from a data controller for damage and distress caused by any breach of the act. Compensation for distress alone can only be claimed in limited circumstances. - 6\. The right to rectification, blocking, erasure and destruction: Individuals can apply to the court to order a data controller to rectify, block or destroy personal details if they are inaccurate or contain expressions of opinion based on inaccurate information. - 7\. The right to ask the Commissioner to assess whether the Act has been contravened: If someone believes their personal information has not been processed in accordance with the DPA, they can ask the Commissioner to make an assessment. If the Act is found to have been breached and the matter cannot be settled informally, then an enforcement notice may be served on the data controller in question. #### Criminal offences created by the Act A number of criminal offences are created by the Act and include: Notification offences: This is where processing is being undertaken by a data controller who has not notified the Commissioner either of the processing being undertaken or of any changes that have been made to that processing. Procuring and selling offences: It is an offence to knowingly or recklessly obtain, disclose or procure the disclosure of personal information without the consent of the data controller. There are some exceptions to this -- for example, where such obtaining or disclosure was necessary for crime prevention/detection. If a person has obtained personal information illegally it is an offence to offer or to sell personal information. #### Unsolicited electronic communications The Privacy and Electronic Communications (EC Directive) Regulations 2003 cover, amongst other things, unsolicited electronic marketing communications. - Unsolicited marketing calls should not be made to individual subscribers who have opted out either directly or by registering with the central stoplist, the Telephone Preference Service (TPS), or to corporate subscribers (e.g. companies) who have objected either directly or by registering on the Corporate TPS. ```{=html} <!-- --> ``` - Unsolicited marketing faxes should not be sent to individuals without their prior consent or to any subscriber who has objected, either directly or by registering on the Fax Preference Service (FPS). ```{=html} <!-- --> ``` - Unsolicited marketing emails or SMS should not be sent to any individual subscriber who has not consented unless the email address or phone number was collected in the context of a commercial relationship. ```{=html} <!-- --> ``` - Wholly automated marketing calls, i.e. where a recorded message is played and the recipient does not speak to a human being, can only be made where the subscriber concerned (whether individual or corporate) has consented. #### The role of the Information Commissioner's Office The ICO has specific responsibilities for the promotion and enforcement of the DPA. Under the Data Protection Act, the Information Commissioner may: - serve information notices requiring data controllers to supply him with the information he needs to assess compliance. - where there has been a breach, serve an enforcement notice (which requires data controllers to take specified steps or to stop taking steps in order to comply with the law). Appeals to these notices may be made to the Information Tribunal. #### Other Useful DPA websites There are several websites which give more details and explanations. We have listed some below: - The Data Protection Act itself can be found at: <http://www.hmso.gov.uk/acts/acts1998/19980029.htm> ```{=html} <!-- --> ``` - The website of the Information Commissioner is at: <http://www.informationcommissioner.gov.uk/> ```{=html} <!-- --> ``` - The website of the Scottish Information Commissioner is at: <http://www.itspublicknowledge.info> Useful information on this topic can also be found on the CILIP website. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.1 Search the CILIP website at: <http://www.cilip.org.uk> for 'data protection act'. Make a note of any aspects of data protection which are particularly relevant to your own work. ------------------------------------------------------------------------ Another aspect of data protection is that related to Government initiatives on privacy and data sharing led by the Ministry of Justice, which aim to increase the data which can be shared by public bodies. You can find information on the website of the Ministry of Justice at: <http://www.justice.gov.uk/information-access-rights/>`</s>`{=html} ### Copyright legislation Copyright legislation is UK-wide and a number of Statutory Instruments have been put in place to ensure that European Copyright Directives are enacted in the UK. The key Act is the Copyright, Designs and Patents Act 1988 which determines what is illegal and what is permissible. \' The purpose of copyright is to ensure that the creator (person who holds the intellectual property right) or owner of the copyright can: - derive any financial benefit relating to their material - have control over the way in which their material is used. Regular revisions of copyright legislation take place so information professionals must keep their knowledge up to date. Copyright law is very complex but it is important that you have a sound knowledge of what is permissible and the role of library staff in enforcing copyright. The Intellectual Property Office website at: <http://www.ipo.gov.uk/> has a good summary of copyright issues. The information on the following pages is extracted from there and summarises the principal points. #### Ownership and duration of copyright The author is the first owner of copyright in a literary, dramatic, musical or artistic work. In the case of films, the principal director and the film producer are joint authors and first owners of copyright. The main exception is where a work or film is made in the course of employment, in which case the employer owns the copyright. The copyright in sound recordings, broadcasts and published editions generally belongs to the record producer, broadcaster or publisher. Copyright protection in the UK is automatic and there is no registration system - so there are no forms to fill in and no fees to pay. Copyright is a form of intellectual property and, like physical property, can be bought and sold, inherited or otherwise transferred. A transfer of ownership may cover all or only some of the rights to which a copyright owner is entitled. First or subsequent copyright owners can choose to license others to use their works whilst retaining ownership themselves. Copyright in a literary, dramatic, musical or artistic work (including a photograph) lasts until 70 years after the death of the author. The duration of copyright in a film is 70 years after the death of the last to survive of the principal director, the authors of the screenplay and dialogue, and the composer of any music specially created for the film. Sound recordings are generally protected for 50 years from the year of publication. Broadcasts are protected for 50 years and published editions are protected for 25 years. The following are useful websites providing information on copyright: - Intellectual Property Office <http://www.ipo.gov.uk/> - Copyright Licensing Agency <http://www.cla.co.uk/> - Copyright, Designs and Patents Act 1988 <http://www.hmso.gov.uk/acts/acts1988/Ukpga_19880048_en_1.htm> #### Copyright and the Internet With the proliferation of electronic communications via the Internet, there has been a massive opportunity created for the infringement of copyright. The Internet provides text and illustrations in electronic format, making it easy for the unscrupulous user to cut and paste web material into their own documents. You will already be familiar with copyright law restrictions on copying material from books and journals. Similar provisions apply to material from the Internet. It is important to make clients aware that they should check the legality of making multiple copies of textual material from Internet sites. The greatest areas of commercial concern have been copyright infringements involving music files and still and moving images. It is clear to see that a digital file can be very easily and at virtually no cost copied and distributed anywhere in the World via the Internet. The creator of the original work is excluded from the process and thus receives no financial reward. Not surprisingly the media companies have been in the vanguard of creating means of prevention. A number of defensive methods have been created to counter copyright infringement in the digital domain. #### Digital Rights Management (DRM) This is a large area but the greatest and most visible use is (and will be even more so in the future) the prevention of copying of films (movies) from DVDs. This requires mechanisms to be active in one or both of the DVD disk itself and the DVD player or computer used. Examples are: - the need to keep a Satellite Television receiver box connected to the public telephone network - certain high definition film disks can only be played back on a computer which is connected to the Internet - the very latest large screen television displays will need a special module to display the coming high definition DVD films. Absence of the module disables the output from the DVD player. The existence of the module guarantees that the incoming digital signal is not being copied. - the regional coding of DVDs which does not allow a DVD disk purchased in the USA to be played on a European region DVD player. You can find additional information at: <http://en.wikipedia.org/wiki/Digital_rights_management> and at: <http://www.ipo.gov.uk/types/copy/c-other/c-protect.htm> #### Digital watermarking This is a computer encryption which is inserted into the image. It is of particular use with images which are placed on websites and thus easily copied. It is invisible to the casual user but provides a tracking mechanism for owners. It is a digital code, which can be unique to the image or shared across the owner's other images. You can find additional information at: <http://en.wikipedia.org/wiki/Digital_watermarking> and <http://www.webopedia.com/TERM/D/digital_watermark.html> Digital fingerprints are unique labels inserted into different copies of the same content (e.g.: an e-book, video or music file) prior to distribution. Each digital fingerprint is assigned to a specific recipient, and thus provides the capability to trace the culprits who use their content for unintended purposes. Fingerprints should be closely associated with the content and difficult to remove. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.2 Visit <http://www.steganos.com> and download the test version of Steganos Security Suite. Install the program and try using it to hide watermarks (or other messages) in GIF pictures. ------------------------------------------------------------------------ ### Intellectual Property Rights (IPR) The growth of Internet use and ease with which files and ideas can be transferred across continents has led to tighter regulation of and concern for intellectual property rights. Intellectual property refers to the rights of the thought process and intellectual creativity which developed the work. Information professionals should be aware of the Intellectual Property Rights issues. You should be aware that intellectual property is the legally enforceable right of the owner. Most countries have laws regulating the copying of inventions, identifying symbols and creative expressions. The UK laws cover four main types of intangible property: patents, trademarks, copyrights and trade secrets, referred to collectively as "intellectual property." Intellectual property has many of the same characteristics as tangible property. It is an asset which can be bought, sold, licensed, exchanged or given away. The intellectual property owner has the right to prevent unauthorised use or sale of the property. Clients should be aware that they should not use library computers (or any others) to do anything which infringes someone else's intellectual property rights, e.g.: by copying content from someone else's website into their own document, or illegally copying music files. You can find lots of additional information at The Intellectual Property Office <http://www.ipo.gov.uk/> ## Freedom of Information legislation and information access issues ### Freedom of Information legislation Freedom of Information legislation was introduced across the United Kingdom at the beginning of 2005. The Freedom of Information (FOI) legislation is different for Scotland from that in the rest of the UK, but the information given here is generally applicable throughout the UK. However you should always check the precise details against the relevant website for your own country. You can find a comprehensive description of the act and its implications at the website of the Information Commissioner at: <http://www.ico.org.uk/for_organisations/freedom_of_information> and for Scotland at the websites of the Scottish Information Commissioner at: www.itspublicknowledge.info The FOI legislation provides a right of access to the information of public bodies by individuals. Information can be in print, electronic, video or audio format. Working in a library you need to be aware of the procedures so that you can assist a client to make an information request on the basis of FOI legislation. You should also be aware of the position regarding your own local authority and its requirements to disclose information. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.1 A client approaches you with a request involving the FOI legislation. He wishes to find out how much money is spent by the local authority on traffic calming measures.Go to the website appropriate to your geographical location and make notes on the process of requesting information which will be useful for clients in the future. ------------------------------------------------------------------------ #### Freedom of Information Act The following details on the FOI legislation is based on information from the Information Commissioner's website: The Freedom of Information Act enables people to gain access to information held by public authorities in two ways: Publication Schemes Every public authority must make some information available as a matter routine through a publication scheme. Information that is included in such a scheme must be made available to the public. A publication scheme is both a public commitment to make certain information available and a guide to how that information can be obtained. General right of access Any person has the right to make a request for information held by a public authority. The authority must usually respond to this request within 20 working days. This right came into force on the 1 January 2005. Exemptions The Act recognises that there are grounds for withholding information and provides a number of exemptions from the right to know, some of which are subject to a public interest test. The Act also sets out procedures for dealing with requests, such as time limits for compliance and fees that must be charged. Making complaints The Information Commissioner is the independent regulator of the Act, with responsibilities to promote the legislation and enforce compliance with its provisions. This includes making decisions as to whether a public authority has dealt with requests properly. ### Acceptable Use Policies For legal reasons each library must have an Acceptable Use Policy (AUP) covering client access to ICT equipment and the Internet. Each authority will have an individual AUP policy reflecting the local circumstances. Each client using the library facilities is required to indicate acceptance of the policy. It is important that the AUP is reviewed on a regular basis to ensure that it complies with current legislation. The AUP must state that Internet access is monitored using manual and electronic resources and that records of Internet access are kept. The AUP should also specify the actions and penalties which could result from contravention of the AUP. This includes providing the police with information where it is suspected that a criminal act has taken place. If you select the People\'s Network Internet Acceptable Use Toolkit there are several examples of local authority AUPs. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.2 Search the internet to find examples of local authority AUPs. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.3 Obtain a copy of the AUP for your own library. Read it over and make a set of notes to enable you to explain the various points to a client new to the library computer facilities. ------------------------------------------------------------------------ ### Content filtering Internet filtering systems used in libraries are designed to prevent clients accessing unsuitable material. When the filtering system is turned on, users cannot open or link to web sites that the filtering system recognises as unsuitable. The filtering system is a software package which can be installed on a PC or a server (to regulate multiple machines). The software can use one or both of two principles. - 1\. When a site is requested, it will check the URL of the site against a list of proscribed sites. If the site is on the list, the software will block access. The list is updated at periodic intervals by the software supplier. - 2\. When a site is requested, the software will check over the site and attempt to recognise key words which would indicate an unsuitable site and then block access. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, think of a disadvantage for each of the above methods. ------------------------------------------------------------------------ #### Approaches to content filtering Although a useful tool, Internet filtering systems are not foolproof. The first method depends on the list of proscribed sites being complete. It would be impossibly expensive for every website on the Internet to be rated using a human observer. There will also be a delay in a new unsuitable site appearing and being added to the list. The second method suffers from the difficulty of placing keywords into context. An example being, it has difficulty in distinguishing between the names of body parts used in a pornographical or medical context. Another example is that access may be blocked to sites containing innocuous words, one component of which may be of a sexual or profane nature e.g. Essex (though more complex filters are now sometimes able to recognise such cases). Also, this method checks only for unaccepatble text, not unacceptable images or speech. Any blocking system can be potentially over-ridden by users with technical knowledge, or by using one of the many proxy sites which allow you to circumnavigate blocks by browsing through a proxy server. reporting websites is another way of controlling what is available, see <http://www.iwf.org.uk/> #### The Family Online Safety Institute (formerly The Internet Content Rating Association (ICRA)) FOSI provide a set of categories and levels within each category: - The presence or absence of nudity - The presence or absence of sexual content - The depiction of violence - The language used - The presence or absence of user-generated content and whether this is moderated - The depiction of other potentially harmful content such as gambling, drugs and alcohol The user's browser has to be configured to use the system. Clearly there are obvious weaknesses here in that website developers are not required to use the ratings, and they may be misused. However, similar to the \'\'\'age ratings\' associated with films and computer games, this may in the long run be the best possibility for filtering. Since there are weaknesses in each approach, filtering can not replace vigilance or simple common sense from library staff. For more information visit <http://www.fosi.org/icra/> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.4 Find out the filtering policies in place in your local authority and what your own responsibility is. ------------------------------------------------------------------------ #### Walled Gardens The walled garden approach is often used for young clients. Here, instead of trying to block access to possible unsuitable sites and allowing access to all other sites, the "walled garden" only offers access to pre-selected websites. This is a much simpler approach. Instead of trying to cope with rating or searching through the 25,270,000,000 websites catalogued by Google today, a small number of hand picked sites are allowed to be browsed. Of course the quality of this service relies upon the nature of the vetting before access is allowed. The disadvantage is of course the exclusion of many potentially useful sites. There have also been issues with e-mail and search engines allowing a hole to be made in the wall. Social networking websites, such as <http://www.facebook.com> and <http://www.flickr.com>, can also be regarded as walled gardens. This is because the owner can control the range of people who view their messages and updates. Another aspect of walled gardens is the barriers which prevent the free flow of information and this is also true of social networking sites with their custom language and proprietary nature. This means that information can't be transferred or access from one platform to another. #### Suppliers of filtering software The following sites are suppliers of filtering software, mainly aimed at young clients, which also provide lots of useful information on internet safety: - SafeSurf <http://www.safesurf.com> - CyberPatrol <http://www.cyberpatrol.com> - NetNanny <http://www.netnanny.com> Trial versions of several of these can be downloaded from the relevant website. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.5 Download an evaluation copy of CyberPatrol and try it out. ------------------------------------------------------------------------ ### Internet safety with younger clients Clearly the previous section covering content filtering is particularly applicable to young clients. It may be appropriate to reserve particular machines for particular user groups with regard to the type of material which may be accessed. This can also be managed by user ID login procedures. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.7 Find out what is the situation in your own library with regard to the reserving of particular PC's for restricted access to Internet materials. Undoubtedly, the younger clients will have the most restricted access. There are serious risks to younger clients with the possibility of someone being hurt, exploited or abused as a result of personal information being posted online or falling victim to "grooming" (covered in Outcome One of this unit). There are many useful websites which promote safe use of the Internet to younger clients, their parents and teachers. Here are three we would recommend you look at: - ClickThinking at <http://www.scotland.gov.uk/Publications/2010/02/09154928/1> - Kidsmart at <http://www.kidsmart.org.uk/> - UK Government Internet Safety Advice at <https://www.gov.uk/search?q=internet+safety> - DirectGov Internet Safety at <http://webarchive.nationalarchives.gov.uk/20121015000000/http://www.direct.gov.uk/en/Parents/Yourchildshealthandsafety/Internetsafety/index.htm> ------------------------------------------------------------------------ #### Illegal material Much material exists on the Internet which it is a criminal offence to access. The catchphrase is 'If it is illegal off-line - it is illegal on-line'. Three types of Internet content are generally regarded as illegal in the UK: - images of child abuse hosted anywhere in the world - criminally obscene images hosted in the UK - criminally racist content hosted in the UK Even though filtering and acceptable use policies are in place in local authorities, breaches can very easily happen. It is important that you are aware of the local procedures for dealing with such situations. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.8 Here are two scenarios involving a client accessing illegal materials. Consult your library service's Acceptable Use Policy and/or staff manual and make notes of what action you would take in each case. 1\. An adult client is observed systematically accessing criminally racist content on a public access PC. 2\. An adult client accidentally accesses images of child abuse whilst carrying out a genuine information search on another topic. ------------------------------------------------------------------------ #### Sources of further information Go to Children Exploitation and Online Protection <http://www.ceop.gov.uk/> This website points to helpful websites for young people and parents containing information about staying safe online at: <http://www.thinkuknow.co.uk/> . The Internet Watch Foundation at: <http://www.iwf.org.uk/> is a site allowing the reporting of websites which host illegal content. It is widely supported and has lots of links and information on the subject of illegal content.
# Applications of ICT in Libraries/Net Navigator This page is designed for the use of students undertaking the Diploma (Diploma ICTL) or the Advanced Diploma (Advanced Diploma ICTL) in Applications of ICT in Libraries. \-\-\-- CHANGES TO THE QUALIFICATION \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-- The Diploma and Advanced Diploma have been superseded by the Professional Development Award in Applications of ICT in Libraries at levels 7 and 8 (English and Welsh levels 4 and 5). They consist of much the same content as the Diploma and Advanced Diploma but the PDAs include two new Digital Culture units. ------------------------------------------------------------------------ These qualifications were developed by the Scottish Library and Information Council (SLIC) and are validated by the Scottish Qualifications Authority (SQA) Carrying Out the Net Navigator Role is an optional unit in the PDA in ICTL Level 8 (Advanced Diploma programme). Information regarding the background to the courses, content and certification opportunities can be obtained by following the Diploma (Diploma ICTL) or the Advanced Diploma (Advanced Diploma ICTL) links. Further information can be obtained from angela.lees@sqa.org.uk ## Define the detail of a complex enquiry in conjunction with the client ### Reference interview techniques for complex enquiries In this outcome we will explore how you should tease out the details of a complex enquiry posed by a library client. We define a complex enquiry as one where: - the sources to be searched for information are not obvious at the outset of the inquiry - the precise nature of the topic requires to be teased out in some detail with the client - a minimum of 3 variables are linked in a Boolean search. From this we can see that the typical client for such complex enquiries is likely (but not always) to be a person with some knowledge or expertise in the subject area. Where this is so, you should capitalise on this at the initial stage and gain as much specific information as possible from the client. #### Defining the nature of the enquiry Defining the precise nature of the enquiry in conjunction with the client is often referred to as the reference interview. However, you may not be able to carry this out face to face. Instead you may carry out the interview over the telephone. Whether communicating face-to-face or by phone, do remember that the reference interview is a two-way interaction or dialogue and you must take responsibility for the efficiency of the communication process. You may use e-mails as part of the process, but we would recommend that, with complex enquiries, the bulk of the reference interview is oral. With a detailed and complex enquiry, you would find it difficult to gather from the client the level of detail which you require from the client through e-mails alone. By the end of the reference interview you should be confident that the nature of the complex enquiry has been fully explored and that the information required by the client has been specifically defined. The reference interview also provides the opportunity to establish any special needs of the client e.g.: visual or auditory impairment. This requires a tactful and sympathetic approach. You may need to ask for assistance from a colleague with specialist knowledge on disability issues. And finally, do remember to record contact details for the client. In the excitement of exploring the enquiry and establishing the client's precise needs, it is all too easy to forget this important information. So check at the end of every reference interview that you have a record of the client's name, address, telephone, fax and e-mail details, as appropriate. If you will be phoning the client, it is also polite to note when it is convenient for the client to receive your call. #### Communication skills Good communication skills are key to the reference interview. This unit outcome provides a good opportunity for practising and refining your communication skills. These include: - Appropriate spoken language - Appropriate body language - Good feedback, especially on the telephone - Note taking - Clear and grammatical e-mails We will briefly examine each of these. #### Spoken language You should use language which is appropriate to the client, avoiding talking down to the client or, at the other extreme, baffling the client with specialist jargon. If you do have to use a term which the client may not understand, e.g. "search engine syntax", be sure to explain it. QUESTION TextEntry1: Explain Dark Internet Conversely a client with expertise in the field they are enquiring about is likely to use specialist or technical vocabulary when describing the search topic. Such vocabulary can be useful for you when you are deciding on your search terms (see Outcomes 2 and 3) but make sure that you fully understand the meaning of any such specialist terms. The client should be able to explain them to you. #### Body language In face-to-face situations, use appropriate body language designed to set the client at ease and promote effective communication. Smile and greet the client by name if possible. Lean forward slightly and use eye contact to show your interest in the conversation. Try to carry out the interview in a place where both you and the client are sitting comfortably and at the same level, preferably side by side. #### Feedback You should use appropriate feedback techniques to ensure understanding of the client's responses. For instance, you might: - Rephrase what the client has said and repeat this back to them - Read out a summary of the enquiry based on the notes you have made. With telephone communications you will have to be careful in order to make sure that you fully understand what the client says because you will get no clues from their body language. See if you can pick up clues from the tone of the client's voice. Conversely, make sure that your tone is positive and encouraging. Smiling as you speak into the phone generates a pleasant tone of voice which encourages helpful responses. #### Note taking In both face to face and telephone interactions, it is essential to take written notes of the main points of the conversation. These notes are your reference for checking that you have fully understood the details of the client's enquiry. Full notes are also useful if you have to put the query on one side for actioning later or pass it on to a colleague to deal with. The more complex the enquiry, the more comprehensive your notes should be. #### Writing e-mails If you are using e-mails to communicate with the client, it is important to establish a cordial tone while remaining concise and to the point. Writing clearly and grammatically is key to this, as is structuring your e-mail well so that the client can follow it easily and respond appropriately. Saving e-mails, both those you send and those you receive, provides a record of your communication with the client. #### Open and Closed Questions In the reference interview, you will use both open and closed questions. These have different uses. It is important to be able to distinguish between the two types of question and to use them appropriately. Closed questions prompt yes/no or short factual answers, such as: - Q. What is the deadline for my getting this information for you? - A. Next Tuesday ```{=html} <!-- --> ``` - Q. Have you checked this reference already? - A. Yes Open questions encourage longer answers, such as: - Q. Can you explain briefly what my colleague did last time? - A. She started with Yahoo and then tried a couple of other search engines as well. I think she was looking it up under something like pagan religions in Wales. We got quite a lot of useful stuff. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, explain at what points during the reference interview and for what purposes you are likely to use: - a\) closed questions - b\) open questions. ------------------------------------------------------------------------ #### Using open and closed questions Closed questions prompting yes/no or short factual answers are mainly used in the reference interview context to: - elicit specific pieces of information from the client - gain confirmation that your understanding of what the client has said is correct - an important feedback tool. You are likely to use closed questions - at the start of the interview when you are taking basic personal details of the client - at intervals throughout the discussion when you want to check you have your facts right - at the end of the interview to sum up and agree on future action. Open questions encourage longer answers and their main uses in the reference interview context are to: - establish rapport with the client, especially in the initial stages of the interview and with clients who are not already known to you - set the scene for the enquiry and gain background information at the beginning of the discussion - encourage input from the client as the interview progresses. So you will use both open and closed questions at appropriate times. When framing a question, always think of the type of response you hope to generate and word the question so as to encourage either a brief or an extended answer. ### Eliciting information and advice from knowledgeable clients = The interview is likely to begin with the client asking you a question. Your task is to probe further until you are fully satisfied that you are clear exactly what the client wishes to find out. Remember to ask for clarification from the client about the topic e.g. ask them to spell uncommon words, expand on the topic under investigation etc. This is particularly important with clients who may be subject experts. While recognising that some clients may be unwilling to give this information, it is helpful if you can establish in some detail the reasons why the client wishes the information requested. One important point to establish is whether they require the information for themselves or whether they are enquiring on behalf of someone else. #### Determining the starting point It is important to ascertain the "starting point" of the enquiry in order to avoid wasting time on finding information which the client already knows. This is particularly important with complex enquiries for knowledgeable clients, where it may be relatively easy to access information at a simple level, when the client actually requires more sophisticated results. In a complex enquiry from a specialist enquirer, it is likely that the enquirer has already undertaken some basic searching on their own behalf. Equally a well-informed enquirer may well be familiar with some or all of the sources of information in their field. You should therefore try to determine what research the client has already undertaken on the topic and what results were obtained. It is often helpful to ask the client's opinion on the usefulness or otherwise of particular sources. A knowledgeable client may also be able to give you some guidance on successful and unsuccessful information searching approaches. However, do not make the assumption that, because the client is knowledgeable about the topic to be investigated, they are well informed about information sources and search techniques. Remember that you are the information-searching specialist (while the client is the subject specialist) and so you should critically evaluate any advice on sources and information searching techniques provided by the client. ### Determining the nature of detailed information to be provided Apart from the actual topic of investigation, there are other factors which need to be taken into account before a member of library staff will embark on the information search, e.g.: the quantity, level and format of the required information. #### Quantity We tend to think that our problem in information searching will be an inability to find enough information. This can indeed sometimes be the case. But using the Internet often results in the reverse situation -- an overabundance of results. Providing too much information is just as unhelpful as providing too little. You must clarify the scale of information required by the client in order to fully satisfy their needs. If the search produces a large amount of information, you should determine whether the client wishes you to undertake any filtering on their behalf before presenting the information or whether they wish to see the full search results. If filtering is requested, you must establish with the client the criteria which are to be applied. Conversely, if the search results are meagre, you should seek guidance from the client as to the possibility of broadening out the search. #### Level It is essential that the information provided is at a level of complexity which enables the client's full comprehension but does not patronise the client or tell them what they already know. The following points give you some guidance as to the likely level of complexity of information required: - the client's age (But remember age does not automatically bring wisdom! Remember too that some young people can display astonishing knowledge and expertise in subjects which interest them.) - the client's educational attainment - the client's display of specialist knowledge - the client's linguistic ability Tactful questioning can be used to make an estimation of the points listed above. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, outline a situation where you know all of the above but this knowledge does not tell you the level of complexity of information required. ------------------------------------------------------------------------ #### Other factors affecting level The most obvious example is where the client is making the enquiry on behalf of someone else. Typical examples would include: - a teacher or lecturer looking for material which could be used by school or college students - parents seeking information for use by their child - a specialist in one field who is a beginner in another e.g.: a consultant surgeon investigating horticulture - a therapist or social worker searching for information for one of their clients Linguistic ability can be misleading. An overseas visitor with a limited grasp of English or someone with a speech impediment may have extensive knowledge of the topic under investigation. You have probably thought of other similar examples. #### Format The results may include information in various formats. There are many formats available, including several as a result of the introduction of ICT. - Your search may direct the client to items of library stock, to be used in the library or borrowed for home use. This could include: - Printed reference sources or information CD-ROMs - Books, audio or video material for home borrowing - Magazines and journals - Pamphlets or leaflets ```{=html} <!-- --> ``` - The search results may be bibliographies or lists of website references for the client to follow up. - The results may be viewed on screen by client, in the form of text, audio or video. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} If the client wishes to view the results on screen on a computer outside the library, what must you ascertain before directing the client to websites with audio or video content? ------------------------------------------------------------------------ #### Other factors affecting format It will be important to check the specification of the client's computer in order to be sure that it will support audio or video applications. Another point to ask about is whether the client had a broadband connection. Downloading photographs, movies or sound on a dial-up connection can take considerable lengths of time (It may not even be possible with dial-up technology.) and is costly in terms of telephone charges. If the search is not carried out with the client present, you must ascertain if the client can visit the library at a later time to access the search results or if the information must be in a format which can be e-mailed or posted to the client. Difficulties may arise if the client has expressed an initial preference for a format in which the information is not actually available. If the information is only available in a limited number of formats, you must alert the client to this and ascertain if any of these formats are acceptable. ### Constraints There may be a number of constrains on the material required. These include: - deadlines for completion - currency of information - language - special needs #### Deadlines for completion It is important for you to gauge the urgency of the enquiry. This can range from enquiries where information is required immediately through to those where the results may be presented after some time has elapsed. You should agree with the client on the deadline for completion of the enquiry and also on the action to be taken should this deadline fail to be met for any reason. If you cannot meet the deadline for completion of the enquiry, clearly it is important to explain to the client the reasons for this. Perhaps the enquiry has turned out to be much more complex than was originally envisaged. A specialist member of staff who would normally have handled the enquiry may be absent through sickness. Technical problems resulting in Internet access being temporarily unavailable can also throw your enquiry off schedule. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} You have explained to the client the reasons for not meeting the deadline. What else should you discuss with the client? ------------------------------------------------------------------------ #### Difficulties in meeting deadlines Although the client may well feel more accepting of the situation if you explain the reasons for your failure to meet the agreed deadline, to some extent this is water under the bridge. More important to the client is the action you propose to take in order to rectify the situation. With this in mind you should raise the issue with the client at the earliest possible stage i.e. as soon as you realise that it is unlikely that the original deadline will be achieved. This gets the client on side and enables you and the client to jointly work out how to make the best of the situation. It could be that it is possible to complete part of the enquiry within the deadline, in which case you must agree with the client which aspects should be prioritised. Or perhaps you could arrange for some or all of the information to be provided by another organisation. The key to client satisfaction is to prevent such a situation happening. Be realistic when agreeing deadlines with the client. If you are unsure of how long the enquiry will take, say so. It is better to overestimate than underestimate the time required. That way the client gets a pleasant surprise when the search results are ready earlier than promised. #### Currency of information In your search you will be dealing with two kinds of information: - Dynamic information changes frequently (e.g.: current information on news, weather, government policy, share prices) and it is important for you to locate the most up-to-date data or, in a historical enquiry, the information as it was at the time being investigated. - Static information is always the same (e.g.: historical dates, chemical formulae). You must also ensure that the client is aware of the need to use recently updated sources for dynamic information and the implications which this may have in terms of the timescale and cost of the search. Updating websites to take account of constantly changing information is costly and it may be that there is a charge or a subscription cost to accessing such sites. This is especially true of sites giving financial and performance information about commercial companies or research results. QUESTION TextEntry1: Static and dynamic information #### Language Some information may only be available in languages other than English. You should be certain of the client's fluency in these languages before embarking on the search. Some websites have a facility which permits you to choose the language. This is usually very simple to do. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.1 Go to <http://www.easyjet.com/en/book/index.asp> and view the site in Italian.Look at <http://www.artis.nl/> and change the site from Dutch to English. ------------------------------------------------------------------------ Some search engines permit you to specify the language of the websites. Some also have a translation facility from a foreign language into English and from English into a foreign language. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 1.2 Try this out in Google. Go to <http://www.google.co.uk/> and click the "Search the web" option, then click on "language tools".Search for websites about "días de fiesta" (this means holidays) which are written in Spanish and located in Mexico.Choose some Spanish text from one of these websites, copy and paste it into the Translate Box and ask Google to translate it into English for you. ------------------------------------------------------------------------ #### Special needs The reference interview provides the opportunity to establish any special needs of the client. Some of the most common examples are: Learning difficulty For clients with learning difficulties you might have to look for material of a simpler nature, perhaps with more visual or audio content English as a second language These clients may prefer material which is not in English. This might mean having the enquirer at your side while you carry out the search so that they can provide assistance with vocabulary. Alternatively, you may be able to pass the enquiry over to a colleague with language skills. (See earlier guidance on language) Physical impairment Any material found must be accessible to the client e.g.: websites must be accessible to a visually impaired client. (See Outcome 4 for more details of this.) If you wish to find out more about the skills and knowledge required for this outcome, the following website may prove helpful. - <http://www.hals.lib.tx.us/ref123/2interview.htm> ## Demonstrate knowledge of search logic, search engines and features of the Internet ### Introduction This outcome looks at a number of aspects relating to web searches, including the following: - Boolean logic - Truncation and wildcards - Non-obvious search terms - Grammar of the Internet - Search engine operation - Search terms - How ranking works - Ownership of the web - Dark internet and invisible web #### Boolean logic Boolean operators are used to combine search terms in order to make the search results more specific. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, can you name the three Boolean operators? ------------------------------------------------------------------------ #### The Boolean operators There are three Boolean operators - AND, NOT and OR. We will explore how each of these is used. AND is used to link search terms. Entering an expression such as beans AND toast means that results will be returned only where both words appear. Using the AND operator narrows your search and gives a smaller number of results. OR is used to indicate that any of the terms may be present. Entering an expression such as punk OR hair means that results with either one or the other (or possibly both) will be returned. Using the OR operator widens your search and gives a larger number of results. The OR operator is particularly useful where a topic might involve synonyms or near synonyms. A search for illness AND felines OR cats will be more wide-ranging than illness AND cats. NOT is used to exclude terms. Entering an expression such as pop music NOT beatles might be devised to return results about pop music but excluding results about the Beatles. Using the NOT operator narrows your search and gives a smaller number of results. The NOT operator is particularly useful when one of your search terms had more than one meaning. Telegraph might refer to electronic communication methods but it is also a common name for newspapers. A search for telegraph development NOT newspaper will eliminate press information. In fact the expressions are pretty close to what you would say in natural speech: - I am looking for references to both beans AND toast. - I am looking for sites on either punk OR hair - I am looking for information on pop music but NOT including the Beatles. Sometimes this is easier to understand in diagrams, so let\'s have a look at Logic diagrams \... #### Logic diagrams: the AND operator Imagine that we have a number of websites which give information about children's clothes. Some of these have information only on girls' clothes, some have information only on boys' clothes and some have information on both boys' and girls' clothes. In the diagrams the left hand circle represents all records including the word girls and the right hand circle represents all the records including the word boys AND ![](Venn-and.svg "Venn-and.svg") girls AND boys The shaded area represents the records which have information on both girls' clothing and boys' clothing. #### Logic Diagrams: the OR operator OR ![](Venn-or.svg "Venn-or.svg") girls OR boys The shaded area represents the records which have information on only girls' clothing, only boys' clothing or on clothing for both boys and girls. #### Logic Diagrams: the NOT operator NOT ![](Venn-not.svg "Venn-not.svg") girls NOT boys The NOT operator excludes all records with information on boys' clothing, and the shaded area represents the records which have with information about girls' clothing only. #### Using multiple Boolean operators It is possible to use multiple Boolean operators. For example, security AND internet AND banking narrows down a search on Internet security issues to records which relate only to bank security on the Internet. QUESTION TextEntry1: Boolean Search QUESTION TextEntry1: Boolean Search 2 You can see how the use of Boolean operators allows a very precise search statement to be constructed. This should produce a smaller number but a better focused set of hits from a search engine. Boolean search logic underlies the operation of all search engines but the various search engines have different systems of entering a Boolean expression. Some allow straightforward search statements using capital letters for AND, OR and NOT. However many do not explicitly allow this, the much used Google being one of them. #### Constructing precise Boolean searches It is important to consult the search engine help pages to understand how you can create a precise Boolean search. There are three approaches: - 1\. Boolean expressions can be entered directly into the search box. We have already covered this. Altavista (http://www.altavista.com/) is a search engine which permits this. - 2\. The search engine makes assumptions about what you mean when you enter search terms. - 3\. There is an Advanced search facility. #### Search engine assumptions If the search engine makes certain assumptions about what you mean when you enter search terms in a particular way. You must understand the implications of these assumptions. Basically when you enter more than one term in the search box, the search engine turns this into a Boolean search. The two possibilities are that the engine defaults to an AND or an OR. Most of the common search engines default to AND. So putting in carriage clock should return results with both words included. Of course the words may appear in any order and not necessarily next to one another. Google allows the use of a minus sign (-) to use the NOT operator. Thus to create the Boolean search expression sixties pop NOT beatles, you would enter sixties pop --beatles (Note: You must not leave a space between the minus and the search term which you wish to exclude.) Google assumes that some common words and numbers are never included in the search. Thus if such a word is particularly required, it must be prefaced by a plus (+) sign. This is essentially the Boolean AND operator. Using + and -- in this way is not as predictable as you might expect in many search situations. We recommend that they should be used only when there is no alternative. You can find out more here <http://www.google.co.uk/help/basics.html> There are more features of search engines you can utilise have a look at Googles help pages on Punctuation and symbols <https://support.google.com/websearch/answer/2466433> and on Search Operators <https://support.google.com/websearch/answer/136861?hl=en> #### Advanced search facility Many search engines have an advanced search facility. This allows many refinements, such as specifying the language, format and age of the sites returned. Most advanced search facilities however have a set of choices which allow a Boolean search to be created. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, take a look at the advanced search facility on Yahoo: <http://search.yahoo.com/search/options?fr=fp-top&p> What expressions are used instead of the Boolean operators AND, OR and NOT? ------------------------------------------------------------------------ #### Advanced searching on Yahoo Yahoo uses With all of the words = AND With at least one of the words = OR Without the words = NOT By placing search terms in one or more of these categories, you can set up most Boolean statements you will need in your searching. Note that it is not only search engines which provide these advanced search facilities. They may also be found within a site. The Houses of Parliament site is an example: <http://www.parliament.uk/business/publications/> #### Other points on Boolean searching A good website covering Boolean searching can be found at: <http://searchenginewatch.com/2155991> A final point about the grouping of terms is that if you want to find results which include an exact phrase, most search engines let you do this by placing the phrase in quotes. e.g. "knitting for children". In the advanced search facility, you are offered a box title "With the exact phrase". This is particularly useful when searching for names where the forename and surname may not be kept together and in order by a search engine. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.1 Try two searches with land act and "land act" as search terms. You will see that the first search produces results relating to Acts of Parliament which relate in some way to land e.g. we found one about stopping dog fouling on public land. The second search leads us to the various Land Acts. ------------------------------------------------------------------------ ### Truncation and wildcards Traditionally on-line database searching allowed the use of truncation of search terms. This used a symbol such as \~ to represent one or more letters at the beginning or end of a word. For example, \~fuse could lead to refuse, defuse or infuse and refus\~ could lead to refuse, refuses, refused or refusing. In Internet searching this symbol would be called a Wildcard. Two types of Wildcard exist, commonly represented by ? and \. - ? indicates the replacement of one character - \ indicates the replacement of any number of characters. Wildcard symbols can be used in the middle of a word, not just at the beginning and end, e.g.: familiari?e for familiarise and familiarize\'\'. You must keep in mind the pitfalls of over-enthusiastic use of wildcards or truncation. For instance, men\* would encompass both men's and menstruate, the latter term being unlikely to be relevant to a search on a male-related topic. Of course the search engines have their own rules. Google for instance does not have this feature. It carries out its own version of using extensions of words automatically. Many search engines use complex algorithms to produce their results which makes the use of wildcards or truncation inappropriate. Most sites which permit wildcard searching will indicate in their Help section which symbols are to be used for these. One search engine which does allow this is Exalead at <http://www.exalead.com/search/> #### Non-obvious search terms A non-obvious search term is a term from some area other than the main search subject which may lead to useful information. This is different from a related term, say using a particular country instead of its continent. A non-obvious search term comes from some sort of parallel area which is at first sight not clear. For example, when looking for information about a particular disease, the name of a researcher in a similar field would be a non-obvious search term. It is likely that you would have to be guided by the enquirer about the appropriateness of non-obvious search terms because background knowledge of the topic would be needed in order to think of them. Another means of finding non-obvious search terms is to browse in directories and portals and see what terms appear in associated sites. You might like to ask your experienced colleagues to give examples of non-obvious search terms which they have used in the past. ### Grammar of the Internet The official name for what we commonly refer to as a website address is URL. URL stands for Uniform Resource Locator. Certain conventions apply to the construction of URLs which can give pointers on their usefulness. (This is also relevant to the validation of website results -- see Outcome 4). Alan November has called this the Grammar of the Internet. (see <http://novemberlearning.com/educational-resources-for-educators/information-literacy-resources/>) or (http://novemberlearning.com/educational-resources-for-educators/information-literacy-resources/4-how-to-read-a-web-address/) http stands for Hyper Text Transfer Protocol. This simply means your browser is looking for a Hyper Text document. Hyper Text is the basic coding used to construct web pages www, as we all know, stands for World Wide Web. The interesting parts are after http and www. The next part is called the domain name. So for instance amazon.co.uk The first part of the domain name may yield useful clues. Is it a well-known name? If you come up with a page on the site <http://www.bbc.co.uk/history/> it has the authority of being on the BBC website. Is it a 'personal' site giving the opinion of only one person? The name of the person may be explicit in the domain name e.g. <http://www.jamieoliver.com/> BUT be terribly careful here. An individual may set up a website to promote their own ideas and then a rival may set up a website with an equally convincing domain name. Remember anyone can set up a domain name of their choice and load any sort of rubbish onto the website. #### Using WHOIS It is often possible to find the owner/publisher of a website by doing a WHOIS search on the domain name. An easy route to this can be found as a facility on many website providers sites e.g.: <http://www.networksolutions.com/en_US/whois/index.jhtml> You can enter the US domain name e.g.: un.org will yield the United Nations Organisation. Any site with a similar name attempting to fool users into thinking it is the UNO can be checked out in this way. The UK site for WHOIS searches is: <http://www.nominet.org.uk/uk-domain-names/about-domain-names/domain-lookup-whois/whois-tool> or go to www.nominet.org ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.2 Use WHOIS to decide which of the following is the official site of Glasgow Celtic football club. - <http://www.celticfc.co.uk> - <http://www.celtic-mad.co.uk/> ------------------------------------------------------------------------ #### URL extensions The final parts of the URL (separated by dots) are called extensions. A well-known example, say for Amazon (www.amazon.co.uk) is .uk which indicates that the website has been registered as of UK nationality. All domain names carry a national identifier as the last extension, except for those registered as being of USA nationality. Taking Amazon as an example: - www.amazon.com No national identifier signifies the United States - www.amazon.co.uk .uk signifies the United Kingdom - www.amazon.de .de signifies Germany - www.amazon.fr .fr signifies France - www.amazon.co.jp .jp signifies Japan ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.3 There are many websites which list these geographical extensions. One of these ishttp://www.iana.org/cctld/cctld-whois.htm Use this or any other appropriate site to find the geographic extensions for the following countries:Indonesia, India, Netherlands, Latvia, South Africa ------------------------------------------------------------------------ Let us look further into www.amazon.co.uk The extension between the company name and the geographical extension describes the type of organisation involved. "co" is for UK commercial companies. Each country has its own method for the domain name extensions. Most of the sites you will be dealing with will be UK or USA based, so let us look at the most common extensions for these countries. #### United Kingdom extensions .gov.uk is a national or local government site e.g. www.opsi.gov.uk the Office of Public Sector Information .co.uk is a company site e.g. <http://www.slc.co.uk/> the student loans company .ac.uk is an academic site e.g. <http://www.soton.ac.uk/> the University of Southampton .org.uk is an organisation, often a charity e.g. <http://www.nationaltrust.org.uk/> the National Trust .ltd.uk is a registered company e.g. <http://www.evans.ltd.uk/> the women's fashion outlet There will be other domain extensions produced in the future. A recent introduction is .me.uk which is presumably meant for individuals. However you must note that only some of these extensions can be relied upon. Only .gov, .ac and .ltd are strictly controlled. Anyone can set up a website with a .co or .org extension. In summary, you can use the domain name extensions as good CLUES (which are watertight for .ac.uk and .gov.uk) but be very careful. #### United States extensions Remember sites registered in the US have no geographical extensions. .edu is an educational institution e.g.: <http://www.wisc.edu/> Wisconsin university .com is any company e.g.: www.amazon.com Amazon the Internet company .org is an organisation (perhaps non-profit) e.g.: <http://www.openoffice.org/> the organisation developing Open Office, the free office software suite. .gov is a Government agency e.g.: <http://www.irs.gov/> Internal Revenue Service .mil is a military institution e.g.: <http://www.navy.mil/> the US Navy .net is used by network providers e.g.: <http://www.discountasp.net/> an Internet hosting company There are several others and some in the pipeline such as .info and .biz which will be used for commercial purposes. Not all countries use these descriptive extensions. Germany and France, for example, only have the country extension. Thus we saw: www.amazon.de for Germany and www.amazon.fr for France. Another point to remember is that there is no requirement to register your site under its country of origin. Some British organisations use the US extensions of .com or .org: www.debenhams.com/ - the well-known retailer www.rsc.org/ - the Royal Society of Chemistry are just two examples. ### Search engine operation There are essentially three stages involved in search engine operation. - 1\. Before you come to type in the search terms, there has to have been an enormous gathering of data about websites carried out by the search engine company. - 2\. The search engine uses your search terms to select candidate sites for the results. - 3\. The search engine returns the results ranked in some order. The Internet is continually being scanned by software set up by the search engine company. This software called a spider or web bot looks for websites and key words to associate with them. The key words can either be metadata (descriptive keywords supplied by the site designer) or words in the text. The result is an enormous data bank of website addresses and their corresponding key words. #### Search terms When the user enters the chosen search terms, the search engine uses complex and proprietary methods to select resulting websites which should satisfy the search - basically the engine is trying to match your search terms against its keywords. Each search engine has its own 'secret' methods, giving weight to particular words, including extensions to search terms such as plurals and so on. These algorithms may change with time and so different results for the same search terms may be obtained if the search is repeated at a later date. #### How ranking works Finally before presentation of the resulting websites, ranking occurs. Ranking is the process by which a search engine orders the results of a search. You would hope that ranking presents the websites most likely to have the most useful information first. However you should be aware that in some cases, commercial sites can buy a place near the top of a list of websites in a search engine's results. The implications of this are that the "best" sites do not necessarily appear at the top of the list. Also the results may appear in a different order at a different date due to ranking changes ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 2.4 A useful exercise is to look at the information pages of search engines to understand how they work. There is usually a section on how to notify the search engine about your website which will have interesting clues as to how the search engine treats new websites. For each of: - Google <http://www.google.co.uk/> - Teoma <http://www.teoma.com/> - Yahoo <http://www.yahoo.com/> look for the "about" pages and find out how the engine works and how you submit a website to it. ------------------------------------------------------------------------ It is important to remember that a search carried out by a particular search engine will return only a sub-set of all the possible results. This is because, due to practical constraints, the engine cannot index all the pages available in the web. An issue here is also how quickly the engine reacts to new or altered web pages. Thus it is always worth using several different search engines for any particular reference enquiry. Of course, there are sites returned in a search, which when clicked upon do not appear at all because the website has been rearranged or removed since the last indexing. ### Ownership of the web The questions 'Who owns the Web?' or 'Who owns the Internet?' come up from time to time. The implications of the answers are crucial to a good understanding of the nature of information on the Web. First, let's get the nomenclature correct. The Internet is the physical network over which information can flow. The World Wide Web (WWW) is a collection of sites where we can access information via the Internet. So the question is now in two parts. Who owns the Internet? (i.e.: the physical network) and Who owns the Web? (i.e.: the collection of information we can access)? #### Who owns the Internet? The Internet is an enormous network which has spread throughout the world. One could say that it is owned by many, many organisations but that is not quite correct. It would be more accurate to say that many, many organisations own their particular part of it. Consider how the Internet evolved. There were a number of scientific research organisations each with a network of computers and terminals. It was agreed to connect these together. Each organisation owned its own network. Gradually more and more commercial and organisation networks were created and joined together. The idea can be likened to the road network on the European Continent. Each country builds and pays for its own roads but it is possible to drive between any two points on the continent because the road network of each country is connected to the next country. Luckily it is worthwhile for each part of the Internet to pay its own way to get the benefit of being connected to the whole network. ### Who owns the Web The other part of the question, who owns the websites, is similarly answered. Each website is owned and financed by an organisation or person. They alone have the rights to place their own information on the website. So Governments will want to have websites to put up information for their citizens to be able to access. Commercial organisations will want to put up websites with information about their products to encourage sales. Other information providers will similarly create sites to distribute knowledge. Then there are millions of websites which are paid for and run by individuals who want to present information about their hobbies, favourite pop stars, family history etc. So there is no one person or body responsible for what exists on the web. It is really quite difficult then to enforce laws proscribing offensive matter because there is no overall control and the offensive site can be situated anywhere in the World. Tim Berners-Lee was the originator of the web and he saw it as a cooperative space for the sharing of information among researchers. He was working at CERN. It still can perform that purpose but the main driving force is now by commercial interests. On-line shopping is a very valuable sector nowadays and in the future there will be more and more commercial uses. However you should be aware of the very different forces influencing what is seen in the search results. There are individuals, organisations and companies attempting to present their own version of the truth, often in an even-handed way, but occasionally in an insidious and very dangerous manner. You must hone your validation techniques so that you can recommend websites which really are what they purport. The concepts of the 'grammar of the internet' can be put into practice here. Note that there are some truly shocking websites which lurk under the most inoffensive names. We are not going to supply any examples of these! ### Dark internet and the invisible web Search engines have become the main means of accessing information on the Internet. In the early days directories were used but these have now relinquished first place to the search engines. This is due to the enormous number of websites. Their number has grown exponentially and Google tells us that today there are over eight billion of them. There is no way that all these sites could be viewed by a human reviewer and placed in a directory. Our ability to find information on the Internet is now very much dependent on the qualities of the chosen search engine. This does mean is that, if there are websites which contain information which cannot properly be accessed by the search engine spider, then we will never see it listed in the results. Indeed there are areas of the web which are never found at all by the searching spiders. A current problem is with search engines being unable to index databases and other websites which generate dynamic content. In other words, the content is not set out on the pages of the website but is generated each time in response to a user accessing the site via a browser. Websites with some content not in HTML also cause difficulties. Examples are proprietary text formats or multimedia. PDF files have also been problematic. If the search engines are not able to find the information then the only hope of finding its existence is by using a Directory. There are specialised portals to 'invisible' websites. One example is www.invisible-web.net which includes a directory of some of the best resources the Invisible Web has to offer. You can read more about the Invisible Web here: <http://oedb.org/ilibrarian/invisible-web/> <http://www.lib.berkeley.edu/TeachingLib/Guides/Internet/InvisibleWeb.html> ## Create and implement a complex search strategy ### Designing a complex search strategy In Outcome 2 we looked at the theory of search logic -- Boolean logic, wildcards, non-obvious search terms, grammar of the Internet, search engine operation and syntax, ranking, ownership of the web, the Dark Internet and invisible web. In Outcome 3 we consider how to apply all of this knowledge in order to design the best strategy for any inquiry. If you are not confident of your knowledge and understanding of the Outcome 2 topics, you will find in beneficial to revise that section before proceeding further with Outcome 3. You can return to the ICTL home page by clicking on the ICTL logo at the top left of the page and navigate to Outcome 2 from there. Complex searches fall into two broad categories: - 1\. You may want to locate a single piece of specific information. - 2\. You may be asked by the enquirer to retrieve everything you can on the topic. #### Locating a piece of specific information What makes the search complex is that this information is not easy to find. For this type of search, you are likely to use one or more search engines. The skill lies in choosing your search terms and combining these into a search statement which will yield the required results. Alternatively, you may know of an authoritative site on which this information will definitely be found. In this case, you will use the URL of the site and then carry out a search within that site for the required information. You should bookmark sites which you find especially useful. You can arrange these in your "Favourites" in topic related folders. #### Retrieving everything on a topic You may be asked by the enquirer to retrieve everything you can on the topic. In many cases, to carry out this instruction to the letter would mean presenting the enquirer with an overwhelming mass of material. The skill lies in designing your search so that it results in a number of the most useful and representative sites, which present sufficient, but not too much, information in the format and style best suited to your enquirer. For this type of search, in addition to search engines, you may need to use directories, portals and databases. With practice you will learn which to use first in specific types of enquiries. #### Useful Search Techniques The key to efficient searching is to construct an appropriate search statement by choosing and combining search terms. You will develop your skills in this with practice. Here are some tips from experienced Internet searchers. 1\. Enter what you consider to be the most important search terms first. For example, rover cars rather than cars rover ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.1 Enter rover cars and cars rover into a search engine and compare the first 20 sites listed. You will find the results differ, although some sites appear in the top 20 listed in both searches. rover cars is more likely to lead to sites which deal solely with Rovers. ------------------------------------------------------------------------ 2\. Enter phrases in quotes (or the equivalent syntax as specific by the search engine). Quotes instigate a search for the exact phrase e.g.: "internet search techniques" will search only for these three words next to each other and in this order. Without quotes, your search will also look for all three words but they could be anywhere in the document e.g.: internet search techniques could lead to sites discussing police search techniques for suspected internet crime. 3\. If you are specifically seeking UK information, either ask to search UK sites only (if the search engine permits this) or add uk as a search term 4\. Do not limit yourself to what we, as library staff, think of as indexing terms. Searching the Internet is different from consulting a printed index. So enter as search terms words that you would expect to find in the text. For example, in a search on teenage health problems, you might use search terms such as bulimia, anorexia, or eating disorder. #### More useful search techniques 5\. Look for distinctive, specific words or phrases which apply to your search topic. This is the best way of narrowing the search to relevant sites. agoraphobia, English madrigals and peregrine falcon are examples. 6\. Remember synonyms and variant spellings. As much of the Internet content originates from the United States, it is particularly important to remember Americanisms e.g.: trunk instead of boot of a car; checking account instead of current account. 7\. When searching on names of individuals or organisations, put these in quotes so that they are a phrase -- "Melvyn Bragg"; "Royal Society for the Prevention of Cruelty to Animals" 8\. When searching for information on an organisation, especially commercial companies, using the organisation's name as a search term often does not lead to the organisation's own web-site but to other sites in which the company is mentioned. (This is a result of the ranking methods used by search engines.) You may be more successful by using the organisation's postcode and/or telephone number as search terms. 9\. Use nouns rather than verbs as search terms, wherever possible. The reason underlying this is that nouns are frequently more specific than verbs. 10\. If you are aware that one of your search terms is ambiguous, add additional terms which define the area in which you are interested. You will find that "michael jackson" "wine critic" uk leads to sites which are less likely to have a connection with the well-known pop singer. ### Reviewing search terms in the light of results -- broader/narrower/related terms It is important to keep reviewing your search strategy and, in particular your search statement, as the search is underway. Ask yourself: Am I finding too much or too little information? - Is the search generating a number of sites which are unconnected, or only loosely related, to the topic? - Is there a slant to the topic which my search does not appear to be including? In order to refine your search, you must be able to use terms which are broader or narrower than or related to your original search term. The words broader, narrower and related are self-explanatory. A good example which clearly illustrates the concept is: initial search term - Great Britain broader term - United Kingdom (The United Kingdom includes Great Britain) narrower terms -- England, Scotland, Wales (Great Britain includes these three nations) related term - Northern Ireland (Northern Ireland is related to Great Britain in that GB and NI make up the United Kingdom) QUESTION TextEntry1: Search term terriers At each stage you should review the search statement, considering if it is appropriate to change the search terms. #### Changing search terms Where the key terms selected initially are yielding too much information, you should move to the use of narrower terms. A knowledgeable client might be able to advise you here. Where the key terms selected initially are not yielding sufficient information, you should move to the use of broader or related terms. Using a directory may help you identify broader, narrower and related terms within its structure. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.2 Enter aeroplanes into the search box on Surfwax. When the next screen appears which summarises the search results, click on Focus and this will show you a selection of Similar, Narrower and Broader terms for aeroplanes. ------------------------------------------------------------------------ ### Collection and presentation of results The results of your search should be presented in a structured way which facilitates understanding by the client. This may require you to extract or summarise information from one or more sites. If you do this, it is important for the client to be informed of the source(s) of the information found so that the client may explore the information further if they wish. The result of the search might be a bibliography of web references or references to information sources in print, audio or video formats. You must quote any such references using a recognised format, for example, as in ISO 690. ISO 690-2 specifies the elements to be included in bibliographic references to electronic documents. It sets out a prescribed order for the elements of the reference and establishes conventions for the transcription and presentation of information derived from the source electronic document. Here is an example of an electronic citation. Monibot, George (2014) \"How we ended up paying farmers to flood our homes\". Accessed via <http://www.theguardian.com/commentisfree/2014/feb/17/farmers-uk-flood-maize-soil-protection> (19 February 2014). ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, state what you think the elements in this citation mean: Monibot George 2014 How we ended up paying farmers to flood our homes <http://www.theguardian.com> 19 February 2014 ------------------------------------------------------------------------ #### Electronic citations The elements of the citation are as follows: Monibot - Author's surname George - Author's forename 2014 - Date of publication of item How we ended up paying farmers to flood our homes - Title of item <http://www.theguardian.com> - URL for website on which item was found. 19 February 2014 - Date this site was accessed Note that because web pages change constantly and can disappear it is important to give the date on which the site was accessed. #### Presenting information to the client You should devise a logical structure for presenting the information to the client. The most commonly used structures are based on these arrangements: - Alphabetical - Chronological - Geographical (grouped by country, region or town) - Topical (grouped by sub-topics) - Categories (e.g.: type of organisation -- public, private, voluntary) - Accepted hierarchies (e.g.: biological taxonomy) - Sites presenting one point of view, followed by sites presenting the opposing arguments QUESTION TextEntry1: Traffic Congestion Search ## Evaluate websites located in a complex search ### Evaluating websites Information on the Internet presents greater problems regarding reliability than information found in reference books and other materials in public libraries which have undergone a rigorous selection process. So ALL information found on websites must be critically evaluated. The more complex the search, the more necessary it is to apply sophisticated evaluation techniques. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, make a list of criteria you might apply to assess the suitability of a website found as a result of carrying out a complex information search ------------------------------------------------------------------------ #### Evaluation criteria We have noted the following nine criteria: - Authority - Credibility - Accuracy - Bias - Emphasis - Currency - Clarity of presentation - Use of multimedia - Ease of use for visually impaired clients We shall now look at each of these in more detail. #### Authority Here you need to consider the expertise and reputation of the organisations or individuals connected with the website. When the information is explicitly attributed to an author, you can assess their reputation. Thus information supplied by an acknowledged expert in a field or found on the website of a well-known and respected organisation carries a lot of weight. Of course a website may give no direct clues as to authorship and hence authority. In this case you can try to find out who owns the site. In Outcome 2 of this unit, we covered examining the URL of the website and carrying out a WHOIS search to find out this type of information. In searching for information about horse breeds you might come across this site: <http://www.ansi.okstate.edu/breeds/horses/> Remembering Outcome 2, what type of organisation does this URL suggest? .edu tells us that this site belongs to an educational institution in the Unites States. In fact, the site is that of the Department of Animal Science of Oklahoma State University and therefore you can expect an amount of authority. Note that some colleges and universities allow their students to create home pages which are not authoritative in the least. You can usually spot this by the name of the student in the URL. #### Tracing website ownership If you were obtaining information about travelling in South Africa, you might come across this site <http://www.springbokatlas.co.za/> From the two domain name extensions you can see that it should be a commercial site (.co) and it is registered as a South African site (.za) You need to access the whois for South Africa. You can do this by searching for it. You can find it here: <http://co.za/whois.shtml> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.1 Carry out this whois search.You can see that <http://www.springbokatlas.co.za/> is registered by the travel company and at the same address as the travel site in Cape Town. That gives a bit of confidence that it is a real company and not a fraudulent 'front'. ------------------------------------------------------------------------ Of course it is pretty rare that a respected organisation's website would not very explicitly feature its own name. You may have to either omit the information found on a non-attributable website or give a strong health warning to the client regarding its usefulness. #### Credibility If the author or organisation is unknown to you, you have to check out their credibility. Regarding a named but unknown author: - a\) there may be a section on the author's credentials, giving qualifications etc. -- you can check out these details. - b\) if no credentials are supplied you can simply carry out a search on the authors' name. What would you look for in the search results? You might be convinced by such things as: - positive references to their names in other articles on respected sites - biographical information showing that they have relevant qualifications or work experience ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.2 When carrying out a search on the history of nuclear physics, you have found a site which quotes extensively from the research of someone called Norman Feather. Carry out a search to determine who this person was and whether or not he was a respected scientist of his time. ------------------------------------------------------------------------ A mark of credibility is in the citing of sources for the information. If the unknown author cites only her/his own sources then you have no clue. #### Evaluating credibility You can evaluate a site to some extent by looking for references to it on other reputable websites. You can check which sites link to or reference the website being validated simply by searching on its URL. Enter the URL into a search engine and it should return a list of websites where the URL is found. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.3 Try this out by searching on www.qca.org.uk which is the URL for Qualifications and Curriculum Development Agency www.qcda.gov.uk. You will find links to many respectable curriculum related sites, including government departments. ------------------------------------------------------------------------ We have now covered a variety of methods which can be used to establish the authority and/or credibility of websites. With experience you will know which method(s) are best in any instance. The next activity provides an opportunity to practice using different methods. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.4 Check reliability of each of the following web pages for authority and credibility: - <http://www.nasa.gov> - <http://blogs.sun.com/roller/page/dcb/?anchor=rocket_science_open_standards> - <http://www.apogeerockets.com/> - <http://www.bbg.org/gar2/pestalerts/> - <http://www.rbgsyd.nsw.gov.au/plant_info/pests_diseases> - <http://www.care2.com/channels/solutions/outdoors/444> - <http://webarchive.nationalarchives.gov.uk/20060711093022/http://www.met.police.uk/history/ripper.htm> ------------------------------------------------------------------------ #### Accuracy Verifying the accuracy on information in a complex search has particular problems for the information professional who cannot be a subject specialist for every search area. The accuracy of factual information can usually be assumed to apply to reputable sites but even then you need to cross check using more than one site wherever possible. You certainly cannot supply information from sites with dubious authority/credibility without a caveat. You must of course use your common sense. You can detect obvious mistakes e.g. a road-based car is not going to travel at 2000 miles per hour although it might in exceptional circumstances reach 200 mph. With more specialised data, you may still be able to get a feel for the numbers and simple mistakes will stick out. #### Bias Here you are looking to see if only one side of an argument is given. Many websites by their very nature present information from only one viewpoint and are thus biased. It is worth examining the URL and whois information. A commercial site is not going to criticise its products negatively. If the site is a personal one, you may be looking at the one-sided views of a 'crank'. If the site is sponsored by a dubious organisation, you may only be able to find this out by looking at the whois data. Of course even well known experts can be biased in their opinions. While such information need not necessarily be excluded from the results presented to the client, you must indicate any identified bias and, if possible, provide information from another sources which present opposing points of view. This is particularly important when the client is seeking information on potentially contentious matters such as politics, religion, race or issues related to pressure groups. One of the most obvious areas where bias is shown is health information. Some sites are simply promoting dubious or unproven therapies with a view to selling their own "medicinal" products. You must make doubly sure that any sites found as a result of a search on a medical topic are reputable. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.5 As an exercise in looking for bias in websites, search for a pair of websites giving opposing points of view on the following topics: - Cats make better pets than dogs - HRT is the only way to go - Why wind farms are bad - Petrol is greener than diesel Have a close look at the arguments. Note how convincing some of these one-sided views can be. You may be lucky when searching for information in a contentious area in that your initial search results in several sites giving the different viewpoints. However, if not, you must be prepared to actively seek out websites giving alternative views. ------------------------------------------------------------------------ #### Emphasis This differs from bias in that it is the omission of information rather than deliberate over-emphasis of one point of view. For example, US sites may devote little space to British developments. Another pertinent example is that sites for UK government departments may include information only for England on devolved issues. You should be aware that emphasis can be more difficult to detect than bias. A solution is to apply the technique of cross checking with other sites on the same topic. Health topics are an excellent example of where emphasis can creep in because of the differing approaches to medicine in different countries. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.6 Insert the search term "chronic fatigue syndrome" into a search engine. Note how the majority of sites which appear are from the United States. Examine the sort of information on these sites. How useful would it be to an enquirer from the UK? Now repeat the search using "chronic fatigue syndrome" uk. Examine the sites listed. We are sure that you will find them more useful sources of information for a client in your library. ------------------------------------------------------------------------ #### Currency In using the Internet you often come across websites which are seriously out of date. In fact some of them are actually abandoned and will never be updated again. When you use websites in your information searching, you must make sure that the information is current. Of course with a reference book you can look at the publication date. However for websites it is not just so easy. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, jot down some points you could look for on a website to establish its currency. ------------------------------------------------------------------------ #### Establishing currency We can think of a few possible ways of establishing the currency of a website. Obviously they depend on finding date information. This can be explicit: - You can check the "Last revised" date on a website. Remember though that this may only indicate the last time a change was made to a particular part of the website and that it does not imply that all the content was updated on that date. - You can look to see how recent are the publication dates of the documents referred to on the site - You can look out for dates quoted within text and make an estimate of currency If there are no actual dates mentioned, you will need to look for implications of dates. - You can look for regulations or laws mentioned in the site and find their dates of introduction. - You can look for the names of institutions or Government departments. These do change name and can be used to give a date range. - You can look for the names of personalities involved in the topic which can show currency. - Finally you can simply look for reference to recent news items which will date the site's information. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.7 Look at the following websites which all provide dynamic information and note the evidence which indicates that each has been recently updated. - <http://www.bankofengland.co.uk> - <http://mascotsuk.com/> - <http://www.thisismoney.co.uk/> - <http://easyjet.com/en/book/index.asp> - <http://www.blenheimpalace.com/> ------------------------------------------------------------------------ #### Currency indicators We noted the following points: Bank of England -- lists recent working papers, conference reports etc. Mascot -- states on home page "Site last updated \[date\]" This is Money -- states on home page "latest news on \[date\]" Easyjet -- the earliest date for booking is today's date Blenheim Palace -- the list of events is completely current. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, can you think of a flaw with the method we used to check the currency of the Blenheim Palace site? ------------------------------------------------------------------------ #### Problems in establishing currency In our Blenheim Palace example, we have established that their events calendar is current. This site also has a section on Properties to Rent. We cannot assume from the fact that the Events information is up-to-date that this section too has been updated (although clearly it would make good commercial sense for Blenheim Palace to make sure that this is done!) Previous versions of a Website The wayback machine at <http://www.archive.org> allows previous versions of websites to be browsed so that the history of a site may be viewed. This can allow you to get a feeling for how it has developed. It also allows or will allow changes in thought or policy to be observed by looking at a website at different points in time. You should, however, be aware that this site is by no means comprehensive. It is possible for website publishers to opt not to be archived. Also there is a limit to the amount of storage for the past websites. In a complex search, it is likely that the results of the reference enquiry will consist of a list of websites. This differs from a simpler search which might only consist of information which you extract from a website. Since the client will have to browse the resulting sites, some further points have to be considered as to the suitability of the websites. #### Clarity of presentation You need to choose sites where the information is clearly presented. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, list the factors you would consider when assessing whether a site presents information clearly. ------------------------------------------------------------------------ #### Presenting information clearly You will want to make sure that the following points are satisfied: - Is it easy to glean specific information from the site? - Is the site easy to navigate around? - Does the site avoid gimmicks such as unnecessary and obscuring graphics? Unless you are in the position that very few websites provide the required information, you can select the best, which satisfy the above points. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.8 Look at <http://www.eca.ac.uk/> It is difficult to find information on the site because of its emphasis on visual gimmicks and use of multiple drop-down menus. Unfortunately a client seeking information on this institution will have little choice but to persevere in using the site. ------------------------------------------------------------------------ #### Use of multimedia The appropriate use of multimedia can enhance understanding and indeed provide additional information. However, some sites include multimedia such as Flash introductions, which at best are annoying and at worst put off the client due to the delays caused. If the connection to the Internet is not fast broadband, then the delays can be intolerable. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.9 Here is an example of a site from a firm offering web design services <http://www.transcena.co.uk> We think its Flash introduction is unnecessary and does not add anything to the information provided. See if you agree with us. ------------------------------------------------------------------------ Some sites offer the option of a Flash and non-Flash version. Look at <http://web.archive.org/web/20050113090553/http://www.blackburn.ac.uk/> and compare the operation of both versions. Which do you prefer? For some searches, information in multi-media format is useful or even essential. You can make this one of your selection criteria. Often just typing video as one of your search terms will lead to sites which have video clips (It can, of course, also lead to sites which are selling videos). We tried jfk, assassination, and video which led amongst others to <http://www.courttv.com/onair/shows/kennedy/vintage_video.html> where video clips can be played. If sound files or sound tracks of movie clips are used, these may require loudspeakers to be available or, more likely in libraries, headsets to be used. Clearly sites where essential information is presented audibly are not appropriate for the hearing impaired. #### Ease of use for visually impaired clients There are two main areas which should be considered for the visually impaired client. It may be that a client can use text on the monitor screen if it is very clear and perhaps large size. Here it is necessary to check that the website text is not partly obscured by background graphics such as a watermark effect. Other considerations are whether the text size can be increased by the user and if there is a text only version of the website. The colour of the text and the background can also influence visibility. It is generally accepted that bright orange, yellow and red backgrounds make text difficult to read. <http://web.archive.org/web/20040710220451/http://www.dundee.ac.uk/djcad/courses/details.php?s=3> is an example. Another practice to be avoided is white or pastel coloured text on a dark background. In a previous version <http://web.archive.org/web/20040101101704/http://battle1066.com/> the banner headline above the coat of arms in this site is difficult for even those with perfect vision. You can compare this with the latest version at <http://www.battle1066.com/> <http://www.abelard.org/technology/net-searching.php> Much of the text here is almost illegible. At the level where the client is unable to read text from a monitor screen a text to speech accessory must be used. For this to be a successful experience, the website must be clearly laid out. Also it is important that all graphics have text descriptions. This is vital when it comes to the use of graphics in navigation through the website. There are guidelines for accessibility and although you cannot be an expert in this area, you will find useful information on the following websites: Two sites covering all accessibility issues: <http://www.coi.gov.uk> and <http://www.becta.org.uk/> A commercial site explains its approach <http://www.santander.co.uk> The RNIB site <http://www.rnib.org.uk/xpedio/groups/public/documents/code/public_rnib008789.hcsp> Recent research by the Museums, Libraries and Archives Council tested websites in the museums, libraries and archives sector and found that only 3% of these met the accessibility criteria set for government websites. You can read more about this research at: <http://web.archive.org/web/20050503012040/http://www.egovmonitor.com/reports/rep11278.pdf> ## Reviewing the Effectiveness of a Search Strategy ### Estimating the effectiveness of a search strategy The client's requirements should have been clearly specified during the reference interview. The first stage in evaluation is to revisit that initial interview and consider if you did indeed fully explore with the client all the aspects of the query. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 5.1 Think of any complex information searches which you have recently carried out. Look back to your initial reference interviews with the clients. Could these have been improved in any way? Note down what you could do better next time. ------------------------------------------------------------------------ Next you must review the results of the search against the client's requirements and consider the success of the search in these terms. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, outline the criteria which you would use to judge whether your search strategy has been successful. ------------------------------------------------------------------------ #### Criteria for success We suggest that you would consider: - Did the search produce results which were relevant to the client's needs? - Did the search produce comprehensive information? i.e.: enough for the client's needs? - And conversely, were the search results sifted in order to avoid deluging the client with information? - Did the search produce information which was reliable, up-to-date and covered all aspects of the topic? - Did you constantly have to modify the search strategy during the course of the search? And were these modifications a result of deficiencies in your original strategy? - Did you meet the client's deadlines for producing the results? - Did your search strategy mean that the search was carried out as quickly and efficiently as possible? You should have no difficulty in applying the majority of the above criteria when considering the effectiveness of your search. The final criteria relating to time and speed may be less familiar to you. #### Time spent searching Time spent on a search is a key evaluation criterion. Given enough time an unskilled searcher could probably produce the required results, but an information professional should be able to produce the requested information much more quickly. You should consider if your search strategy produced the results in the minimum possible time or whether any modifications of the search strategy would have yielded speedier results. Key to this is the choice of search engines, directories, search terms and logic. Finally, do remember that it may not be possible in all cases to fully satisfy the client's requirements. (If this is the case, you will have explained the reasons for this to the client, e.g. information does not exist in the format specified, and proposed some alternatives if this is possible.) Failing to fully satisfy the client's requirements is not in itself a criticism of your search strategy. If the information does not exist, the best search strategy you can devise will not uncover it. It does, however, give you a pointer for the next time you are asked to carry out a similar information search. If you have doubts as to the existence of the information requested, share this with the client right at the start so that they are not disappointed later. ### Measuring the cost of a search The cost of an information search arises from two components. The cost of staff time (yourself and colleagues) dedicated to the search and direct costs, i.e.: anything which has actually to be paid for. An effective search strategy should mean that staff time input is minimised, thus keeping down the cost of the search. It can be easy to overlook the cost to the library service of staff time because public libraries do not normally charge for this. Commercial libraries often ask library and information staff to log the time spent on information searches and the enquirer's department is then billed for this. We are not suggesting that you formally log time spent -- merely that you keep aware of roughly how much time you are devoting to any information search and whether this is justified. If you find yourself devoting an inordinate amount of time to any search, ask yourself whether you should: - modify your search strategy - ask advice from a more experienced colleague - ask a more experienced colleague to take over the search for you - abandon the search at this point, explaining the reasons for this to the client. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, note down any direct costs which you think could be associated with an information search on the Internet? ------------------------------------------------------------------------ #### Direct costs Direct costs could include: - Telecommunications charges - Fees for subscription sites - Charges to download particular documents - "Pay-per-view" costs for commercial sites Telecommunications charges will have been paid by your library service. They represent a fixed overhead and so you do not need to try to calculate them for any search. Where a library service, has decided to subscribe to a particular information source, there will be good reasons for this. A knowledgeable person has decided that the subscription site provides better information than is available on free sites. Indeed the subscription service may provide the only information available. You should therefore familiarise yourself with the content of subscription sites and their charging structures. Downloading and pay-per-view charges can mount up. Before using such information, always consider if there is an appropriate alternative source which is free of charge. An interesting article on the development of \"pay for content\" Internet provision is found at <http://web.archive.org/web/20040206000441/http://www.demonatthus.net/news/n-a030407a.html> Another cost which can be considerable relates to printing and/or copying the search results. This can be minimised if you supply the results to the client in electronic format wherever possible. ## Use ICT to set up current awareness and alerting services ### Determining current awareness requirements of clients You should begin by establishing an information profile for the client. This will provide information about what information the client needs and the quantity, level and format of the required information. It will also specify any constraints, such as deadlines for completion, currency of information and language and note any special needs that the client might have: Example Information Profile The following information profile might suit a client who wants to be kept up to date on happenings in the Scottish Parliament: Client name: Joseph Grant Email address: jgrant@btinternet.com Age: 35 Education: Completed six years secondary school Information Required: Regular updates re Scottish Parliament Quantity: Brief summary with links to full stories Level: Literate adult Format: Daily digest Deadlines: Wants to start ASAP Currency: Updated daily Language: English Special Needs: None You can find an example of online profile form at: <http://web.archive.org/web/20060705204606/http://sciweb.lib.umn.edu/general/profile.phtml> #### Establishing an information profile Establishing an information profile uses essentially the same skills and techniques as the first part of this unit, i.e.: - Reference interview techniques - Eliciting information and advice from clients - Determining the nature of detailed information to be provided-- quantity, level, format - Constraints -- deadlines for completion, currency of information and language - Special needs of the client If you want to review these topics, you can click the ICTL logo at the top left of the page to return to the Unit 6 home page and navigate from there to Outcome 1 of this unit. In addition to establishing the nature of information required, what else would you need to agree with the client in order to provide a satisfactory current awareness service? It is also essential that you should agree the update frequency with the client. e.g.: weekly, monthly, whenever a change occurs, on-demand etc. #### Costs You should take into account the costs (in staff time or subscriptions to commercial services) of providing updates and should be realistic about their frequency. Remember that your time costs money and it is unrealistic to spend disproportionate amounts of it in meeting the needs of a small number of clients. Also, commercial services can be expensive to use: if you do not already subscribe to a service, it may be uneconomical to do so to meet the needs of a small number of clients. Some commercial services also incur a usage charge, in which case you must ensure that this is not excessive. ### News services A news service is one which provides regular updates on topics commonly regarded as news, i.e.: those topics covered in newspapers and television or radio news broadcasts, such as current events, politics, sport etc. News is a distinct category for current awareness because of the need for immediate notification of breaking events as well as regular summaries. There are a wide variety of news sites to choose from. Three methods of delivery may be distinguished: - daily digest via e-mail. This gives the subscriber a brief daily summary of newsworthy events, usually with links to more detailed stories. - breaking news events by e-mail. This lets you receive instant details of new stories, more or less as they break - online news ticker permanently visible on the computer monitor. This scrolls news headlines continuously across the bottom of the screen and is updated with new stories as they happen. It often provides hotlinks to more detailed coverage. All three have their own advantages and disadvantages. The daily digest is non-intrusive and allows you to follow up such stories as you choose, but you only receive updates once a day. The breaking events coverage lets you know as soon as something happens, but you have to check your email to see it. The online news ticker lets you know about new stories instantly, but some people find it an annoyance having it on the screen all the time. Some e-mail delivery services allow the use of filters, which give an element of choice of news topics delivered. If you are setting up a news delivery service for a client, it is vital that you use this filtering in order to tailor the service to the client's needs. #### Daily digests You can obtain a daily digest from the following sources: - BBC: <http://newsvote.bbc.co.uk/email/news> OUT OF DATE try this.. <http://www.bbc.co.uk/news> - Google: <http://www.google.com/alerts?hl=en> - The Scotsman: <http://auth.jpress.co.uk/login.aspx?ReturnURL=http%3a%2f%2fwww.scotsman.com%2ftemplate%2fEmailPreferences.aspx&SiteRef=SCOT> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 6.1 Choose one of the above services and sign up to receive a news digest. Remember, you can always cancel it later if you don\'t like it. ------------------------------------------------------------------------ #### Breaking news You can obtain breaking news alerts from the following sources: - BBC: <http://news.bbc.co.uk/1/hi/help/3533099.stm> - Google: <http://www.google.com/alerts?hl=en> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 6.2 Choose one of the above services and sign up to receive breaking news stories. Remember, you can always cancel it later if you don\'t like it. ------------------------------------------------------------------------ #### Online tickers Online tickers are available from the following sources: - Reuters: <http://www.microsite.reuters.co.uk/ticker/uk/godownload.htm?src=marketing> - BBC: Currently being upgraded, but check at <http://news.bbc.co.uk> TRY <http://news.bbc.co.uk/1/hi/help/4801459.stm> You can find a list of news tickers at: <http://www.journalismnet.com/choose/newstickers.htm> It\'s unlikely that you could install these on library machines due to security restrictions, but you might have to explain to clients how to put tickers on their own PCs. \-\-\-- ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 6.3 Go to <http://www.journalismnet.com/choose/newstickers.htm> and look at the tickers. Which ones look as if they might be useful to you and why? ------------------------------------------------------------------------ #### News aggregators news aggregators, use an XML format such as RSS, to receive relevant news headlines. XML stands for eXtensible Markup Language and is a standard format for computer-readable documents which makes it straightforward to process them automatically. RSS stands for Really Simple Syndication. It\'s a method of describing news or other Web content that is available for syndicating (i.e.: feeding or distributing) from an online publisher to Web users. The term "syndication" derives from the newspaper industry practice of sharing content between different papers. A column or a cartoon (such as Peanuts) which appears in numerous different papers is described as "syndicated". There is a useful introductory article at: <http://www-106.ibm.com/developerworks/library/w-rss.html?dwzone=web> and another at: <http://news.bbc.co.uk/1/hi/help/3223484.stm> To read rss feeds sign up to a free account at netvibes A news aggregator is a software application that collects syndicated content from a variety of sources and displays it as a single web page. A website may incorporate aggregator features by republishing syndicated content on one or more of its pages. Aggregator features also can be added to other client software, such as Web browsers, e-mail clients, weblog creation programs, or media player programs, to allow these programs to display syndicated content. You can get more information from: <http://en.wikipedia.org/wiki/News_aggregator> #### News providers Another way to make the topic choice more focused is by the choice of provider. The FT ticker would be a good choice for stock market data. If you carry out a simple search on Google, an array of sites providing specialised news will be found, e.g.: www.bunkerworld.com offers both an e-mail delivery service and a news ticker devoted to the happenings in the world of bunker fuel. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 6.4 Use Google to find specialised news providers on the following topics: - The Middle East - ComputingTake a note of the two most interesting ones in each category. The ones we found included the following: The Middle East - Globalvision News Network: <http://www.gvnews.net/html/index.shtml> - AME Info: <http://www.ameinfo.com/45876.html> - Gulf in the Media: <http://www.gulfinthemedia.com> Computing - SearchMobileComputing: <http://searchmobilecomputing.techtarget.com> - News.Com <http://archive.is/20121208135346/http://news.com.com/> - Network Computing <http://www.networkcomputing.com/netnews/> ------------------------------------------------------------------------ ### Website updating services Some commercial websites offer an alerting service detailing new products. Of particular interest to library professionals are the alerting services of journal and book publishers. For journals, it is possible to get the table of contents and sometimes abstracts of the articles. One example is the content alerting feature in <http://www3.oup.co.uk/jnls/> for Oxford University Press Journals. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 6.5 Go to <http://www3.oup.co.uk/jnls/> and sign up for alerts for one or more of the OUP journals. ------------------------------------------------------------------------ For book publisher alerting services it is possible to include filters to receive information on particular types of books. An example is the Mailing List feature on www.heinemann.com Booksellers also offer alerting services, with www.amazon.co.uk being an obvious example. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 6.6 Go to www.amazon.co.uk and subscribe to their alerting service by clicking on the New for You link in the left-hand column. ------------------------------------------------------------------------ You can find links to the website alerting services of many major publishers and vendors at: <http://www.lib.cuhk.edu.hk/information/publisher.htm> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 6.7 Go to <http://www.lib.cuhk.edu.hk/information/publisher.htm> and sign up for one or two alerting services which look useful to you. ------------------------------------------------------------------------ Alerting services are not confined to books and journals. For example, Stay Smart Online (http://www.ssoalertservice.net.au/view/80956e10461f4446acbcab5cae348a0c) is an Australian Government service, designed to provide small businesses with accurate, plain English advice to help protect computers, mobile phones and other devices from malicious attack. #### Monitoring websites The contents of websites change and often do so at unpredictable intervals. If you want to be notified when the contents of a website change, without having to connect to it frequently to check, you can set up an alert to notify you of any changes. If an alert can be set up it can solve two problems. Firstly if there is a substantial change to an often-recommended site, you can check up to see if must be re-evaluated for recommendation. Secondly, if data contained in a site is updated at say annual intervals, it is useful to know when the new data becomes available. This is similar to knowing that a new edition of a reference work has been published and needs to be purchased. Some websites offer to notify subscribers automatically if changes are made, but there are a number of tools available which allow you to monitor changes on any website, e.g.: - Website Watcher <http://www.aignes.com/features.htm> - Check and Get: <http://activeurls.com/en/> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 6.8 ------------------------------------------------------------------------ Download an evaluation version of the software from one of the sites given above and use this to set up alerts fro two or three websites you visit frequently. ### Creating a current awareness system for your own organisation A current awareness service is a service or publication designed to alert scholars, researchers, readers, customers, or employees to recently published literature in their specialist field(s). Current awareness systems are usually available in special libraries serving companies, organizations, and institutions in which access to current information is essential. Such services can be tailored to fit the interest profile of a specific individual or group. Some online catalogues and bibliographic databases include a \"preferred searches\" option that allows the library user to archive search statements and re-execute them as needed. Current awareness services are sometimes referred to as selective dissemination of information (SDI). Internal current awareness systems have traditionally involved the physical circulation of print materials to clients. These have now been replaced by electronic versions. This includes identification of relevant materials which match the client's information profile. The materials might include internal documents in electronic or print format. You should be able to identify relevant print or non-print materials from journals, reports etc. Where such are available only in print format, you should give a reference and a brief description. You should be able to operate a system for e-mailing information to clients within the organisation at agreed intervals and set up web-sourced current awareness services for internal clients. You can find lots of links relating to current awareness services for librarians at the following sites: <http://www.city.academic.gr/special/libproject/LIBRARY_SITE/information_services/LIBRARY_SERVICES/alerting_services.htm> <http://www.lboro.ac.uk/departments/dis/disresearch/ascas.html> Although these are university library sites, much of the content is applicable to public libraries. You can find a long list of available current awareness and alerting services at the following location: <http://www.tru.ca/library/guides/current_awareness/current_awareness_a-z.html> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 6.9 Draw up information profiles for one or two of your colleagues and set up current awareness services for them by using some of the resources mentioned in the sites listed above. ------------------------------------------------------------------------
# Applications of ICT in Libraries/Educator This page is designed for the use of students undertaking the Level 8 PDA (Advanced Diploma ICTL) in Applications of ICT in Libraries. These qualifications were developed by the Scottish Library and Information Council (SLIC) and are validated by the Scottish Qualifications Authority (SQA) Carrying Out the Educator Role is an optional unit in the Level 8 PDA programme. Information regarding the background to the courses, content and certification opportunities can be obtained by following the Level 7 (Diploma ICTL) or the Level 8 (Advanced Diploma ICTL) links. Further information can be obtained from angela.lees@sqa.org.uk ## Establishing ICT training needs for individuals or groups ### Training needs analysis Before embarking on designing and delivering any training programme you must establish your precise objectives. This means determining: - 1\. the existing skills, knowledge and competences of each of the learners - 2\. the skills, knowledge and competences the learners require in order to operate effectively in their existing work role or to progress to a different work role - 3\. And, from 1 and 2, the gap in skills, knowledge and competence which the training is designed to address. It will be the objective of your training that each participant learns enough to eliminate this gap. This process is often called a Training Needs Analysis (TNA) or Learning Needs Analysis (LNA). For Outcome 1 you must demonstrate that you can carry out a straightforward TNA for individuals and groups of learners. The first step then is to make an accurate estimate of the learner's current competence. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, outline what may happen if you embark on delivering training without ascertaining the existing skills, knowledge and competence of your learners. ------------------------------------------------------------------------ #### TNA problems There are two equally damaging scenarios. At one extreme you may have overestimated the learners' skills and knowledge. You therefore pitch your training at too high a level. If you are lucky, the learners will point this out to you and you may be able to think on your feet and do a quick redesign of the training. However, if you find yourself having to devote a considerable amount of time to bringing the learners' skills and knowledge up to the point at which you thought you would be starting from, you will be unlikely to be able to achieve the final learning objectives in the original timescale. If you have overestimated the skills of only one or two members of a learning group, it is quite likely that they will not draw your attention to this. Instead they will sit quietly, not wishing to appear foolish in front of their colleagues. In this situation they will learn little and will become demotivated and disinterested. At the other extreme you may have underestimated the learners' skills and knowledge. You will then find yourself delivering training which covers areas which they already know -- "teaching Granny to suck eggs". Your learners are likely to become quickly disenchanted and possibly aggressive. If this applies to only one or two in a learning group, these learners are likely to switch off and may distract other group members. From these examples, you can see the importance of really knowing your learners before you start. #### Estimating ICT Competence Learners may have acquired differing levels of ICT competence through: - formal training in the workplace - experience in the workplace - off-the-job training such as an ICT course at school or college - personal development and experience outside work. Where skills and knowledge come from non-workplace environments, it is important to make sure that they are transferable into a workplace setting. ICT skills and knowledge usually do transfer readily. Thus your TNA should relate to competences from both work and non-work environments. The obvious place to start is with the learners themselves. However, people are, depending on their personality, often inclined to underplay or alternatively exaggerate their ICT competence and experience. So you will wish to corroborate the learner's estimates of their competence through hard evidence or the views of other people. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, think of who else, apart from the learners themselves, might be able to provide you with useful information on a learner's ICT competence. ------------------------------------------------------------------------ #### Sources of information regarding ICT competence You might usefully consult some or all of the learner's: - line manager or immediate supervisor - colleagues - previous tutors or trainers from within and outside your own organisation - clients in the library who will have received a service from the learner which is ICT related. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, note down as many techniques as you can which you might use to gather information on the learner's competence from the learner themselves or from any or all of the people listed above. ------------------------------------------------------------------------ #### Information gathering techniques You might use some or all of: - direct observation of the learner using ICT in the workplace - examination of work samples or work records belonging to the learner - practical tests and assessments of the learner's use of ICT - questionnaires or checklists covering key ICT competences - the learner's staff appraisal reports - interviews or focus groups with learner, manager, colleagues, tutors, clients #### Direct Observation This is one of the most reliable methods for you to gauge the learner's competence. You will see for yourself exactly what they can and cannot do. You can supplement this by questioning to extend to situations which occur rarely or would be emergencies. Use questions like \"What would you do if the system crashed at this point?" or "Can you think of an occasion when what you have just done would not be appropriate?" There are a few disadvantages with direct observation. The learner may feel nervous and so under-perform. Alternatively, they may "play to the camera", although this is usually easily spotted. The main drawback is that observation must be done on a one-to-one basis. It is therefore time-consuming. Another difficulty can be that you have to arrange a time which is convenient to both you and the learner and when work conditions allow the learner to carry out the specified tasks. #### Examination of Work Products ICT tasks often produce printed materials or electronic records which are stored in the computer. These demonstrate clearly what a learner has been capable of. #### Practical Tests and Assessments You may be able to devise a short pre-training assessment which all learners will undertake. Make sure that this assesses only the knowledge and skills which are directly relevant to the proposed training (and, it goes without saying, to the work to which this training is related). Devising assessment material is a skilled task. It is always advantageous to have a dummy run with a couple of volunteers who will give you unbiased feedback and point out any ambiguities or deficiencies in the assessment. You may be able to get assistance in devising assessment materials from your Training or HR Department. #### Questionnaires or Checklists Questionnaires or checklists can be completed by the learner themselves or by other people who can give an informed opinion as to the learner's competence. It is important not to make these too detailed. You should home in on the key competences only. Here's an example of a checklist which might be used to establish a learner's competence in using applications under Microsoft Windows. Please tick the box which best describes your ability to carry out each of the tasks below: ----------------------------------------------------------------------------------- ------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------- ---------------------------------------------------- Task I have done this often and am confident about my ability I have done this quite a few times and I would probalby be able to do this in most situations I have done this occasionally and would need some reminders about how to do it again I have never done this Run an application from the desktop or by using the Start menu Create a new folder Open a document and use the Save and Save As options Save a document in different formats Print a document Cut, copy and paste within a document, between documents and between applications ----------------------------------------------------------------------------------- ------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------- ---------------------------------------------------- #### Staff Appraisal Reports Staff appraisal documents are, of course, confidential. However, with the agreement of the member of staff concerned you may be shown relevant extracts relating to ICT skills. #### Interviews or Focus Groups These an take place with learners, managers, colleagues tutors or clients and may be one-to-one or group interviews. It is vital to obtain the consent of the learner before you invite opinions from others as to the learner's ICT competence. It is equally important to reassure others that the learner has agreed to your interview with them. In some cases the learner may be able to suggest appropriate interviewees who could provide valuable insight into their ICT competence. In all cases it is essential to start the interview by explaining the reasons why you are exploring the learner's ICT competence. It is good practice to use a checklist to ensure that you get all the required information from each interviewee. #### Areas of competence You can use these techniques to profile the learner's existing ICT skills in the areas of: - hardware - operating system environment (e.g.: Windows) - packages used (e.g.: Word) - the library's own ICT management system - the Internet In Outcome 1 of Unit 3 we discussed in some detail the areas which you would want to explore under each of these headings. If you want to review this material, you can click the ICTL logo near the top left of the page to return to the Unit 7 home page and navigate to the relevant Outcome from there. #### Learning objectives The next stage is to determine your learning objectives, i.e.: the skills and knowledge which it is intended all learners should possess at the end of the training. These will usually be related to: - improving the learners' competence in their current job - preparing for planned new ICT devleopments which will impinge on the learners' current job - upskilling so that the learners can move on to a different job which requires increased ICT competence. To determine the required skills and knowledge, you can use the same or modifications of the methods for assessing existing ICT competence ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, look at this list again: - direct observation of learner using ICT in the workplace - examination of work samples or work records belonging to the learner - practical tests and assessments of the learner's use of ICT - questionnaires or checklists covering key ICT competences - the learner's staff appraisal reports· interviews with learner, manager, colleagues, tutors, clients Remembering that this time you are focusing on the end product of the training, amend the list to show the methods you could employ. ------------------------------------------------------------------------ #### Methods of gathering information We think that this time you will lay more emphasis than previously on evidence from people other than the learner. Of course, it is still important to consult the learner in order to gain their views on the skills which they think they require. However, at this stage you are likely also to consider: - direct observation of others using ICT in the workplace, e.g.: staff already employed in a post to which the learner may aspire - examination of work samples or work records belonging to others, e.g.: a colleague in a similar job to the learner who demonstrates greater ICT competence - questionnaires or checklists covering key ICT competences, e.g.: completed by managerial or supervisory staff - interviews with managers, supervisors and colleagues in similar posts or in promoted posts - literature provided by suppliers of new/upgraded ICT equipment which it is intended to install in the library. And finally having gathered all your evidence as to the existing skills and knowledge of your learners and the competence which are the end result of the training, you can design an appropriate training programme to upskill the learners to the required level. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, consider what approach you might adopt if your training needs analysis establishes that the ICT skills of your small group of learners differ considerably. ------------------------------------------------------------------------ #### Dealing with differing skill levels Your approach might be to design individual learning programmes for each learner which they can work through independently of their colleagues. However, it is probably more cost-effective to bring the skills of all group members up to a common base level and then provide group training from that point on. You might, for instance, arrange for three of the group to work through some basic ICT learning packages in the library before you delivered some group sessions on simple Internet searching. ## Selecting a delivery approach ### Learning styles We all learn in a variety of ways but each of us tends to have one learning style with which we feel most comfortable. Many educational theorists have written about learning styles and the implications of these for delivery of training. One well-accepted approach is that of Honey and Mumford who identified four main learning styles: - activists - reflectors - theorists - pragmatists According to Honey and Mumford, different learning activities are associated with each of the four learning styles. #### Activists Activists prefer new experiences, opportunities to tackle problems and difficult tasks. They like challenges, generating new ideas, brain storming, leading others. Their philosophy is: \"I\'ll try anything once\". They tend to act first and consider the consequences afterwards. They are gregarious and like learning in a group with other people, although they can tend to try to centre all such group activities on themselves. #### Reflectors Reflectors are thoughtful people who prefer to collect all the facts and data and consider every aspect of a situation before taking action. They will listen to others' opinions and experiences and learn from these. They are likely to adopt a low profile in group discussions but enjoy observing other people in action. #### Theorists Theorists prefer a clear structure, focus and purpose and will want to know exactly what is expected of them. They like to have time to think logically about ideas and situations and try to fit these into a pattern. They learn by thinking problems through in a step-by-step, logical way. They like to analyse and synthesise. They are uncomfortable with subjective judgements, lateral thinking and anything flippant. They are happy to learn alone without group support. #### Pragmatists Pragmatists learn best through concrete activities which let them try out ideas, theories and techniques. They like to have the opportunity to practice what they are learning with feedback from a knowledgeable mentor. As they are essentially practical, down to earth people who like making practical decisions and solving problems, they tend to dislike long-winded and open-ended discussions. Although each learner is likely to have one preferred learning style, everyone can use a mixture of styles, depending on the type of learning and the occasion. QUESTION TextEntry1: Different Learning Implications #### Other approaches to learning styles The approach of Honey and Mumford is just one way of looking at different learning styles. If you wish to explore this further, you will find some good summaries of other approaches at: <http://www.learningandteaching.info/learning/experience.htm> Another way of categorising learners is to measure their attributes in terms of: - 1\. Active vs reflective - 2\. Sensing vs intuitive - 3\. Visual vs verbal - 4\. Sequential vs global. You can learn more about these learning styles and their implications for design and delivery of training at: <http://www.engr.ncsu.edu/learningstyles/ilsweb.html> This also includes a short online questionnaire which you can be used to determine your own learning style. That\'s the end of this section. You can review any topic by using the menu at the left-hand side of the screen, or move on to the next section: Delivery approaches ... ### Delivery approaches When we explored the four different learning styles, we realised that the trainer must choose appropriate delivery methods in order to accommodate the styles of the learners. Another equally important dimension to consider is matching the delivery method to the nature and content of the learning. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, list the most common types of delivery method which you might be able to include in a programme of workplace training. ------------------------------------------------------------------------ #### Delivery methods Among the most common delivery methods are: - "chalk and talk" - demonstration - group problem solving - role playing and simulations - practical activities, individually and in groups - individualised learning, e.g. from a book or an e-learning package - videos and other media. #### "Chalk and Talk" This phrase is often used to describe traditional teaching. The picture it conjures up is of the trainer in front of the group of learners, giving a talk on some topic. Nowadays, the "chalk" element is more likely to be a whiteboard, flipchart or a PowerPoint computerised presentation. This method is suitable where the trainer wishes to impart theoretical knowledge to the whole group of learners. We absorb more information from what we see than from what we hear. So it makes sense always to include visuals, either on the board, chart or screen or through handouts or posters. The learners' attention span will be limited when they are required only to listen to someone talking. Good practice is to introduce a variation by asking questions of the learners, encouraging the learners to ask questions of you or by interspersing your talk with group discussions. #### Demonstration The trainer will demonstrate how to carry out a practical activity to either a group of learners or to an individual. You might be able to incorporate demonstrations from other people -- experienced colleagues or one of the group who is more skilled than the others. When group demonstrations are involved, it is crucial that every group member can observe the demonstration clearly and has the opportunity to ask questions of the demonstrator. #### Group Problem Solving Team working is one of the most highly prized skills in the workforce of today. Any training which involves group problem solving has the multiple advantage of: - improving the learners team working skills - developing the particular competences related to the training topic - enhancing the core problems solving skills of the learners. Problem solving activities need to be carefully structured by the trainer. A useful approach is to encourage the learners to adopt a process of Plan--Do--Review. This ensures that they progress to the stage of evaluating their problem solving strategy and learning from it: not just designing and implementing a strategy for solving the problem. #### Role Playing and Simulations These offer the opportunity for participants to practice in a safe environment and to learn about situations which occur only rarely or which involve danger and emergency action. However, role-playing and simulations should be used sensitively, remembering that many learners feel apprehensive in artificially constructed situations. #### Practical Activities Hands-on practical work has an important role to play in workplace learning. It offers the learners the opportunity to develop skills in a real situation, with the equipment they will actually use on the job. Do make sure that there is enough equipment. In particular, it is unwise to double learners up on terminals to undertake computer-related tasks. This usually results in one (the more confident) learner carrying out all the tasks, while their partner passively watches. #### Individualised Learning You may have access to commercially produced learning packages (print or electronic) which are applicable to the training you wish to deliver. The alternative is to design your own -- but be warned - this requires considerable skill and time input on the part of the trainer, if a polished and professional product is to result. #### Videos and other media It is common to use audio or video material in learning sessions. These provide the opportunity to engage the learner by introducing experiences from beyond the training room or the library service. And they can provide a welcome change from the trainer's voice! ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, complete the chart below. ------------------------------------------------------------------------ Which learning activity(s) would be most suitable for the training topics listed? -------------------------- ---------------------------------------------------------------------------- ------------------------------ ------------------------------- ----------------------------------------------------------------------- New health and safety regulations and their implications for the workplace Dealing with awkward clients Operating the new e-catalogue Catching up for two learners who missed the previous learning session "chalk and talk" demonstration group problem solving role-playing/simulations practical activities individualised learning Videos and other media -------------------------- ---------------------------------------------------------------------------- ------------------------------ ------------------------------- ----------------------------------------------------------------------- #### Choosing learning activities It is possible to think of a scenario when you might use each of the activities for any of these topics. However, we think the most fruitful choice is likely to be. -------------------------- ---------------------------------------------------------------------------- ------------------------------ ------------------------------- ----------------------------------------------------------------------- New health and safety regulations and their implications for the workplace Dealing with awkward clients Operating the new e-catalogue Catching up for two learners who missed the previous learning session "chalk and talk" X demonstration X X X group problem solving X role-playing/simulations X practical activities X individualised learning X Videos and other media X X -------------------------- ---------------------------------------------------------------------------- ------------------------------ ------------------------------- ----------------------------------------------------------------------- ### Motivating learners Motivation is the key to all successful learning. You may have designed a wonderful training programme but if the learners are not motivated to learn, your efforts are doomed to failure. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, make a list of factors which can demotivate learners ------------------------------------------------------------------------ #### Demotivating learners We could demotivate you by giving a long list here! But instead here is a summary of what we think are the main demotivators for learners. The training itself: - The training is at too high or low a level. - Learners have been compelled to attend the training without the reasons for their participation being adequately explained. - The topic appears irrelevant to the learners. - The trainer has not outlined clearly at the start of the training what the specific learning objectives are. - The training is delivered badly. - The learning environment is poor. The learner: - Learners have had previous negative experiences at school, college or of workplace training. - Learners are distracted by problems unconnected with the learning. #### Level of training If the training is pitched at the wrong level, it will result in learners who are either struggling to cope or bored. Neither category of learner will be particularly motivated to learn. If you have carried out the training needs assessment properly, this should simply not occur. Learners for whom the training would have been at too high a level should have received preparatory training to upskill them and extend their knowledge to the competence required. Learners for whom the training would be at too low a level should either simply not attend or could be slotted in part way through the programme at the point at which the learning becomes relevant to them. #### Other demotivating factors We will group the next three points together as they are closely linked. - Learners have been compelled to attend the training without the reasons for their participation being adequately explained. - The topic appears irrelevant to the learners. - The trainer has not outlined clearly at the start of the training what the specific learning objectives are. We take it as read that the topic is relevant to the learners - otherwise there is no justification for you to deliver the training. Reasons for attendance should be clearly explained to the learners in advance and links between the proposed training and their work demonstrated. It is especially important to outline the benefits to the learners themselves (as opposed to the library service) which will result from the training programme. You might be able to show, for instance, how learning to use a new computer program could cut down on boring, repetitive manual tasks. As the trainer you may either discuss these issues yourself with the learners in advance of the training or, alternatively, you should ensure that another person does so, most probably their line manager. In the later case you may find it helpful to construct a briefing sheet. At the start of the training programme you will outline your specific learning objectives and how you intend to deliver the training to achieve these. At this point you should clarify what your expectations of the learners are and, conversely, what support the learners can expect from you. #### Badly delivered training We hope that when you have completed this unit, this will not be the case! However, let us list a few common pitfalls which you should try to avoid. - Trying to pack too much material into a learning session - Poorly produced visuals - Irritating mannerisms on the part of the trainer, e.g.: jingling coins in pocket, fiddling with jewellery - Poor delivery, e.g.: mumbling, speaking too quickly - Lack of variation of learning activities - Poorly structured learning programme, e.g.: no logical flow through content (See Outcome 3) - Trainer does not have sufficient knowledge or skills in topic #### Poor learning environment We are using the term "learning environment" to encompass the venue, the equipment, the resources etc. You should make sure that any practical issues which might demotivate the learner are minimised. Examples might be too high or too low temperatures in the training room, training sessions which start late or over-run, extraneous noise or distractions, technical problems with ICT equipment, interruptions from colleagues seeking information on day-to-day work. And do make sure that all mobile phones are switched off before the training commences. #### Previous negative experiences Obviously establishing a friendly, reassuring relationship with the learner is crucial here. It may also be helpful to expand on the differences between the current training programme and any previous negative experiences which the learner has had. You could emphasise for instance that your learners will be able to work at their own pace, can practice what they are learning in the workplace with support from more experienced colleagues, will not have to sit formal examinations or test etc. One major motivator is for the learner to see that they have achieved something. Success breeds success. The implication of this for you as the trainer is that learning programmes must be broken down into small sections and the objective and sub-objectives for each section should be clearly explained to your learners. For instance, if the training relates to word processing, a sub-objective might be for the learner to become competent in left, right and full justification of text. #### Distractions If a learner is worried about personal problems, they will be unable to give their full attention to learning new things. This is possibly the most difficult demotivator for a trainer to tackle. After all, you can do little if one of your learners is experiencing financial difficulties, marital problems or is concerned about their health. All you can do in these circumstances is to reassure the learner that you are sympathetic to any difficulties which they have shared with you and that you will attempt to accommodate any special requests resulting from them. You may be able to take some action about more practical problems though. An example would be if the training occurs at the venue which is not the learner's normal workplace, resulting in childcare problems because of long journeys by public transport. By allowing such a learner to leave ten minutes earlier, you might be able to resolve the situation. If you wish to read more about the theory of motivation and its application to training, you will find a good summary at <http://www.learningandteaching.info/learning/motivation.htm> ## Design of learning materials and programmes on ICT related topics ### Defining learning objectives You should define learning objectives in specific terms. Learning objectives usually involve a statement of: - the task or knowledge involved, i.e.: what must the learner be able to do or know? E.g.: save data in a spreadsheet - the condition, i.e.: how will it be performed? E.g.: without reference to the Help facility - the standard, i.e.: how well must it be performed? E.g.: correctly in 90% of cases It is generally accepted that all learning objectives should be SMART (Specific, Measurable, Achievable, Realistic, Timebound.) You can find more information about this at <http://explearning.ucf.edu/registered-students/tips-for-success/writing-smart-learning-objectives/195> You can find useful guides to writing learning objectives at the following locations: A Quick Guide to Writing Learning Objectives: - <http://www.nwlink.com/~donclark/hrd/templates/objectivetool.html> Guidelines for Writing Learning Objectives: - <http://apha.confex.com/apha/learningobjectives.htm> Writing Quality Learning Objectives <http://www.learninginstitute.qmul.ac.uk/wp-content/uploads/2011/05/Aims-and-Outcomes-Guide.pdf> #### Bloom\'s Taxonomy You may find it useful to investigate Bloom's Taxonomy as a framework for writing learning objectives. In 1956 Benjamin Bloom wrote a book entitled "Taxonomy of Educational Objectives" which has been widely adopted within the educational community as the de facto way of classifying cognitive competence. An updated version of the book, edited by Anderson and Krathwohl was published in 2001. You can easily find it at www.amazon.co.uk and other online bookshops. Bloom's Taxonomy is a simple way of categorising cognitive skills. It has six levels: - 1\. knowledge - 2\. comprehension - 3\. application - 4\. analysis - 5\. synthesis - 6\. evaluation. You can get further information at: <http://www.bobbyelliott.com/Taxonomy.htm> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.1 Choose a simple task, e.g.: "Using tables in Word" and write learning objectives for it. (Try to choose a task which is of some relevance to you, or to one of your clients, as we'll be using it for activities throughout this section.) ------------------------------------------------------------------------ #### Structuring learning In structuring learning you should take account of the learning cycle. In its simplest (3 stage) form the way in which learning takes place may be expressed as plan, do and review. See <http://www.wilderdom.com/experiential/elc/ExperientialLearningCycle.htm> for more detail. or Kolb's more sophisticated version: <http://www.businessballs.com/kolblearningstyles.htm> #### Learning sequence You should be able to devise a logical sequence for the learning, taking account of which parts of the learning are a precursor for others, moving from simpler to more complex concepts and grouping related topics together. Any session should have a beginning (where the objectives are clearly stated and agreed by the candidate and the learners), a middle (where the learning activities are undertaken) and an end (where the learning is summarised and next steps agreed). The learning plan should be made clear to the learners when the learning programme commences. In structuring the learning the candidate should ensure that a variety of learning experiences are included to prevent tedium from demotivating the learner. You can find a lot of useful information about structuring learning from the link below. Although it is specifically aimed at teachers, most of the information given is equally applicable in other learning contexts. <http://www.teachfind.com/national-strategies/foundation-subjects-strand-key-messages-about-structuring-learning> ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.2 Draw up a learning plan to allow a specific client to achieve the objectives you listed in the previous activity. Your plan should take account of the client's preferred learning style. ------------------------------------------------------------------------ #### Using ICT to create learning materials Your approach to the use of software to create learning materials will be dependent on the availability of software within your own organisation. There are several courseware creation packages available, which can be used. Although they offer many features to include multimedia etc., the vital advantage is that they provide routing (branching and looping) through the material allowing learners to take their own appropriate path. They can also provide automated and recorded assessment. One easy-to-use package is Course Genie, which lets you create course materials in Word and convert them automatically to HTML. This software has now been superceeded by Wimba Create: <http://www.wimba.com/products/wimba_create> This site also offers extensive demos on the use of the software. Other examples of content creation software include Authorware, Director and Dreamweaver (http://www.macromedia.com) and products such as Lectora (http://www.lectora.co.uk). It should be noted that these are complex products and you may require specialised training to achieve maximum benefit. If specialised software is not available, there are other ICT routes. Word processing software such as Microsoft Word can be used to author content. Graphics, animations, videos and sound files can also be included in the document, as well as text. Animations and sound files will then operate when the document is viewed on a computer. A more polished package can be created by using presentation software such as Microsoft PowerPoint. The greatest advantage is that this will create a page-based approach. Additionally a common look can be created throughout the whole package. Again, sound or still and moving visual effects can be incorporated. You should have knowledge of how both specialised and general software can be used to create a learning package and have experience of authoring with either general or specialised software. You can use a site like: <http://www.jiscrsc.ac.uk/scotland> which has a range of practical units on making the most of Microsoft software aimed at designing simple learning episodes. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.3 Use the package of your choice to create a short learning episode designed to meet one of the objectives you outlined earlier. ------------------------------------------------------------------------ #### Selecting and merging content from internal and external sources You should appreciate that it is not always necessary to produce original content for learning packages. A wealth of learning material is available through the Internet and much of this is copyright free for educational purposes. You should ensure that any chosen material matches the learning objectives and style of the complete package and that the use which is made of the chosen material is fully compliant with copyright. You can often find useful materials quickly with a search engine, but you may also like to check some of the following links: The BBC offers a number of useful online courses on PC-related topics: <http://www.bbc.co.uk/learning/onlinecourses/> You can find useful online resources for learning about Microsoft Office products at: <http://office.microsoft.com/en-us/training-FX101782702.aspx> If your library is an SQA centre, you may be able to get access to the PC Passport materials produced by SQA. You can get more information at: <http://www.sqa.org.uk/pcpassport> If you have access to these materials you can download them in Word format, allowing you to modify them if you wish. There are also a number of low-cost or open source courseware suppliers. For example, Moodle is open source software widely used by schools, colleges and universities ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 3.4 See if you can use a search engine to locate any resources which would be useful for meeting the learning objectives you outlined earlier. ------------------------------------------------------------------------ ## Support individuals and groups in their use of learning materials ### Types of support We often see the terms coaching, mentoring and training used in relation to workplace learning. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, can you write down a short definition of each of these terms, as you understand them? ------------------------------------------------------------------------ #### Support roles Although there may be some argument over the precise meaning of these terms, the following definitions bring out the key differences between them. In coaching, the learner and the coach are active collaborators. The coach observes the learner in a real, naturally occurring workplace situation as they try to complete tasks. The coach provides hints, help, and feedback as needed. Mentoring involves a sustained relationship between the learner and the mentor who offers support, guidance, and assistance. Training is more formal learning, and more of a one-way process, where the trainer imparts skills and knowledge to the learner. #### Coaching Coaching was originally used in business to describe support given to people who were seen as under-performing in some way. Now it is more usually seen as a means of supporting people on the job in order to help them improve their competence and achieve their maximum potential. The analogy of the sports coach developing the tennis player to improve their techniques and win more matches may be helpful. Coaching is generally considered to be a fairly short-term activity, related to specific objectives. It consists of a one-to-one interaction between the coach and the person being coached in a relatively informal setting. The aim is to provide the learner with feedback in their performance together with suggestions on how to improve from a knowledgeable and skilled person. Skilled coaches know when to be directive and when to be passive. They can distinguish between situations when it is appropriate to intervene to support the learner and when it is more effective to permit independent learning even though this involves the learner making mistakes. #### Mentoring Mentoring has become very fashionable in the last few years. Although mentoring is a relatively widespread practice there is no formal definition of what mentoring is but, generally speaking, it could be defined as a relationship between two people - the mentee (the person being mentored) and the mentor - which will positively affect the development of at least one of them. Note the phrase "positively affect the development of at least one of them". This recognises the fact that most mentors will say that they too have gained from the experience of mentoring. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 4.1 Think of people who have had a significant influence on the development, progression and direction of your career. You may come up with several. Now identify what they did which influenced you. ------------------------------------------------------------------------ #### Significant influences You will probably find that the people who have affected your career significantly: - Guided you - Supported you - Created opportunities for you - Provided a role model for you. By doing one or more of these things they were fulfilling the role of a mentor in some way. Someone who is designated as a formal mentor will do all of the above. The mentoring relationship will last over a period of time. This allows mentor and mentee to get to know and trust one another. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, write down the qualities which you consider a good mentor would require. ------------------------------------------------------------------------ #### Mentor qualities We think that a good mentor should: - Provide a good role model - Possess excellent communication skills - Be able to empathise with the mentee - Recognise that learners have different motivations, skills, knowledge and needs and be able to capitalise on these - Be good at spotting learning opportunities and challenges which will assist the mentee's development - Be well informed about the objectives and content of the training programme being undertaken by the mentee in order to provide maximum support - Provide meaningful feedback to the mentee - Understand that sometimes it may be necessary to push the mentee to move out of their comfort zone - Encourage the mentee to think for themselves and work out solutions to problems From the above you can appreciate how useful coaches and mentors could be in supporting the learning programme which you are delivering. To find out more about coaching and mentoring, look at: - <http://www.coachingnetwork.org.uk/ResourceCentre/WhatAreCoachingAndMentoring.htm> #### Training Training is more directive than either coaching or mentoring. It involves the learners receiving input from the trainer in the form of instruction. Training is always specific and may be long or short term. The trainer is your role! This unit explores the skills you require and the methods you may use to deliver direct training to the learners. As the trainer, you must consider the ways in which coaches and/or mentors could contribute to the progress of your learners. You must exercise care in the choice of staff to undertake the coaching/mentoring role. As well as having the necessary work-related knowledge and skills, they must be in a position to devote time to coaching/mentoring and should be able to develop a real rapport with your learners. QUESTION TextEntry1: Coaching, Mentoring or Training ### First line ICT support You are designing and delivering training on ICT related topics. It is therefore very likely that your learners themselves will be operating ICT equipment as part of the learning programme. When a learner is using any type of computerised equipment, it is likely that from time to time some technical snags will arise. You must be able to assist the learner with straightforward trouble shooting e.g. printing problems because the page set-up is not correct; computer "hanging"; changing screen resolution. You should also be able to assist any learner with special needs to use appropriate features of the technology. We are not suggesting that you should possess sophisticated trouble shooting skills: this is the responsibility of ICT technical staff. You should simply be able to cope with typical, straightforward difficulties which can arise. The next few pages summarise some of the most common problems you are likely to encounter, together with some tips on how to solve these. #### The monitor appears blank - Check to see if the computer has 'gone to sleep' by pressing the space bar on the keyboard. - Check that the monitor is switched on and connected to the mains i.e. is the power light illuminated? - Check that the monitor is correctly connected to the computer. - Check to see if the system works after the computer is reset or switched off at the mains and on again. #### The computer hangs Sometimes, after using the computer for some time, it 'hangs'; neither keyboard nor mouse appears to operate. - Wait a while to see if the computer is performing some intensive task and recovers. - Try CtrlAltDel. If you are lucky it will bring up a task manager window which will show you which application is not responding and allow you to close down only that application. - Use the reset button to restart the computer. - Switch the computer off at the mains and then on again. #### Monitor text is too small Sometimes a client has difficulty reading off the monitor because the text is too small. - If this is confined to a particular application, it is usually possible to adjust the zoom setting. If this does not appear in a box near the top of the window, it will be found in the menu system under View: Zoom or View: Text size. - If this applies to everything on the monitor, then, if you have access rights, you can change the monitor settings. Right click with the mouse on the desktop, choose Properties from the resulting menu, choose the Settings tab from the dialogue box, reduce the Screen resolution setting and OK. Unfortunately, the lower the screen resolution, the less can be displayed on the monitor. This often results in an uneasy compromise for people with problems with their sight. #### Nothing comes out of the printer - Check that the printer is switched on and connected to the mains i.e. is the power light illuminated? - Check that the printer is correctly connected to the computer. - Check that the printer has paper in it. - Check the ink supply. - Try printing a test page. - Check the print settings in both the operating system and the application to see that the computer is looking for the correct printer and that the correct size of paper has been selected and that manual/auto (as appropriate) is chosen. #### Print layout is wrong Sometimes the printer does not seem to use the whole of the sheet of paper and the layout is not the same as on the monitor. When using a word processor like Word, it is possible to set the paper size in the application. However there is also a setting for the printer itself. If these two settings are different, then the output will not appear correctly on the page. The driver for a newly connected printer may default to US legal for the paper size. It is normal to use A4 in this country and applications will use this as default. Go to the printer properties and check the paper size. Start: Settings: Printers: right click on the printer concerned, choose Properties and select the Device settings tab. #### Disk is full Sometimes, when saving data from an Office application like Word, the message comes up that the disk is full. - It may be that the client's floppy disk or pen drive is full. This is quite likely for any sizeable word-processed document especially if it contains graphics or other embedded items. - A fault condition can arise concerning interaction between the application and the operating system which results in a false reporting of the disk full error. This is irretrievable and requires the computer to be rebooted. If the client will lose a fair amount of unsaved data, it is worth opening a new document and copy and pasting from the original to the new document and then trying to save that. You may be lucky! - Note: a similar problem can occur regarding the computer running out of memory. Again only rebooting the computer will correct the situation. #### The printer jams There is no universal solution for this problem as each printer has its own unique mechanism. The best you can do is to familiarise yourself with the various types of printer in your library and how to un-jam each. ## Evaluate and revise learning materials and programmes ### Assessing learner progress When the learning programme is underway, you will want to review regularly how your learners are progressing towards their objectives. We should make it clear at this point that this unit is intended for library staff who find themselves in the role of educators and not for those who are required to undertake formal assessment of learners for National or Scottish Vocational Qualifications or other workplace awards. That type of assessment must be undertaken by someone who has an assessor or teacher qualification. In this unit we are concerned only with assessment which will give feedback to the learner on his/her progress towards the learning objectives and to you, the trainer, as to how effective the learning programme has been. (You may see this referred to as "formative" assessment.) In this context you will use methods which are as non-threatening as possible to the learner. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, note down any ways that you could use to assess how well your learners are progressing. ------------------------------------------------------------------------ #### Methods of assessing progress We can think of quite a few methods of assessing learner progress. Two of the commonest are: - Direct observation - Examination of products #### Direct Observation The most immediate method is to observe directly the activities being undertaken by the learners during the learning programme. From this you will get a clear idea as to whether your learners are actually managing the tasks they have been set and how well they are coping. While you are not in any way 'giving marks', you can use this information in two ways. Firstly you can use it to provide a little bit more assistance to any learners having difficulty. Secondly you can use it to assess the success of your own approach in delivering the learning. Trainers benefit from observing the learners at all points in the learning programme, not just when they are involved in specific tasks. Their facial expressions and body language will give you feedback on how well the training is being received. If you notice a learner, yawning, fidgeting or gazing out of the window while you are explaining a topic, it is unlikely that they are absorbing the information fully. Perhaps they know this information already, perhaps the material is too advanced for them, perhaps your explanation has confused them -- in all of these cases, you need to take some action in order to re-engage them in the learning process. #### Examination of products Many of the learning activities you will ask the learners to undertake will produce a result which can be checked. This may be a printout or screen dump or perhaps a file. This is an excellent method to use for feedback purposes because, if your learning is well designed, the product will not be seen as something artificial, produced solely for assessment purposes. Also, as evidence, it should be fairly incontrovertible, either there will be a result or not. Examining products gives you feedback without the learner really being aware that their performance is being assessed. You can simply review the product with the learner, leading naturally into a discussion of how easy it was to produce this, how it might be improved etc. #### Assessment 'lite' You may find it useful to use some methods which veer in the direction of traditional educational assessment. For example, you can carry out a quiz or use a simple tick box test. You can construct these yourself or tap into ones which experts have designed. ------------------------------------------------------------------------ ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="50"} ACTIVITY 5.1 Go to <http://www.learner.org/courses/neuroscience/interactives/interactive2.html> and try the learning related quiz which explores whether your left of right side of the brain is dominant. This quiz is quick and fun to complete. Although it is simple it would give you some useful feedback on your learners if you asked them to complete it before embarking on the learning programme. ------------------------------------------------------------------------ When making up simple tests, it is best to confine yourself to TRUE/FALSE or "fill in the blanks" (sometimes called CLOZE) questions. Compiling multiple-choice questions requires a great deal of skill and is best left to specialists. #### True/False Test on Word Processing Indicate if the following statements are true or false. ------------------------------------------------------------------------------------- ------- ------- ------- 1 To copy and paste, you use Ctrl C and Ctrl V True 2 A text with a straight margin on the right hand side is called "right justified" True 3 Pressing the Delete key removes letters to the left of the cursor. False 4 We change the colour of the text by highlighting it and left clicking False 5 Arial is the name of a font. True 6 Left clicking on a word in the text activates the spell checker. False 7 The "save as" command is used to save a copy of the document as a duplicate file. True 8 To change the style of bullet points, you must go to the format menu. True 9 A running title along the top of pages in a document is called a tag line. True 10 You use the thesaurus feature to find alternative spellings of a word True ------------------------------------------------------------------------------------- ------- ------- ------- #### Cloze Question on Word Processing A text with a straight margin down the right hand side is called\_\_\_\_\_\_\_\_\_\_\_ justified. #### Direct Feedback Here you can obtain feedback from individual learners using verbal interaction. This can best be done during or perhaps towards the end of a training session. You can also allow the learner to create direct feedback by issuing scorecards. The learner can use these to record the tasks in which they consider themselves to be competent as they progress through the learning. #### A simple scorecard This illustrates a scorecard for a learner who is part way through a learning programme on training needs analysis techniques. +:--------------------------------------------------------------------:+ \| Training Needs Analysis Techniques \| +----------------------------------------------------------------------+ \| Use this scorecard to record your competence in the use of the \| \| techniques covered in the programme. You are asked to review this at \| \| the end of each weekly session. \| \| \| \| The numerical scale represents \| \| \| \| 0 = I have no experience of this at all \| \| \| \| to \| \| \| \| 5 = I am 100% competent in using this technique \| +----------------------------------------------------------------------+ \| \| +----------------------------------------------------------------------+ \| Direct observation of the learner using ICT in the workplace \| +----------------------------------------------------------------------+ \| Examination of learner's work samples or work records \| +----------------------------------------------------------------------+ \| Practical tests and assessments of the learner's use of ICT \| +----------------------------------------------------------------------+ \| Questionnaires or checklists covering key ICT competences \| +----------------------------------------------------------------------+ \| Examination of the learner's staff appraisal reports \| +----------------------------------------------------------------------+ \| Interviews with learner, manager, colleagues, tutors, clients \| +----------------------------------------------------------------------+ \| Focus groups of learners, colleagues, managers etc. \| +----------------------------------------------------------------------+ #### Computer Based Assessment Some ICT based learning packages incorporate diagnostic tests which score and benchmark learner competence automatically as they work though the package. It is best to use a method where the learner sees the result and not something which appears secret and is suddenly sprung on the learner at the end of the course of learning. Alternatively you can use special software such as Hot Potatoes to create your own computer based assessment tools. If you wish to read more about this, look at: <http://www.ucl.ac.uk/isd/staff/e-learning/tools/hot_potatoes> ### Designing feedback tools The previous section dealt with evaluating the learning you have developed in terms of assessing the learners' progress towards the learning objectives. It is also important to evaluate the learning you have developed by getting feedback on the learning experience. As you can imagine, the overall quality of the learning experience has a deal of effect on the rate of progress of the learner. ------------------------------------------------------------------------ ![](T_cap.gif "T_cap.gif"){width="50"} Before proceeding, note down which aspects of the learning experience you would want to ask the learners about. ------------------------------------------------------------------------ #### Aspects requiring feedback Here is a list of issues we would expect to be included in feedback on the learning experience. You may have thought of some additional points. - Were the learning objectives relevant? - Did the content match the stated learning objectives? - Was the quality of the learning materials satisfactory? - Did the trainer provide sufficient support? - Was the trainer's presentation clear? - Was the learning environment pleasant? - Were there any deficiencies or problems with the equipment? - Was the learning experience enjoyable? You can see that we have included a mixture of issues relating to learning objectives and delivery/support, as well as on the learning environment and enjoyment. #### Objectives related issues - Were the learning objectives relevant? - Did the content match the stated learning objectives? This area is important because the learner's perception of the relevancy of the objectives is what matters. If you are not getting this relevancy over to the learners, then you will have great motivational problems. Also once the learner has accepted that the objectives are relevant, they must experience the content you provide as being the correct material. Although trainers may sometimes dismiss negative feedback from one individual learner in this area, it is clear that a low score from a significant number of learners for this area needs a serious response on your behalf. #### Delivery related issues - Was the quality of the learning materials satisfactory? - Did the trainer provide sufficient support? - Was the trainer's presentation clear? This are core areas for you as a trainer because they are the areas you have most control over and input into. If the learners consider the quality of the learning materials to be unsatisfactory, you should probe this further to find the exact cause of their dissatisfaction -- were the materials at the correct level, clearly expressed, professionally presented, attractive to look at etc. Different learners will require varied levels of support from the trainer. In this instance, negative feedback from just one or two learners is significant because it can indicate that you have tailored your level of support to suit the majority of the group and ignored the needs of those who are finding the learning more difficult than average. Individual learners will undoubtedly have different views on the learning experience in terms of the trainer's delivery -- an element of personality is involved here. But again, if there is not a broad positive result from your learners in this area, you will have to look very closely at what you are doing. #### Learning environment issues - Was the learning environment pleasant? - Were there any deficiencies or problems with the equipment? This area is one where the trainer may have limited control. If you are allocated a dingy windowless room in which to carry out the training, or if you are given an old slow PC to carry out your ICT demonstrations on, you will have real problems in providing a good learning experience. Try to pre-empt complaints on the learning environment by resolving any such difficulties in advance of delivering the learning. #### Enjoyable experience - Was the learning experience enjoyable? Finally we consider an overall question as to whether the learning was enjoyable. Is this a valid question? Well, if the learners did not enjoy the experience, it is unlikely that they benefited fully from it or that they will ever come back willingly for more! #### Feedback form design There are different methods of obtaining feedback. You can use paper forms handed out to the learners, or utilise a computerised approach. #### Types of feedback form As we saw on the previous page, you should try to create questions which are: - relevant to the area to be evaluated - expressed in neutral terms so as not to prompt a certain answer - clearly phrased and non ambiguous. In order to compare feedback from different learners or groups of learners, it is best to design feedback forms in which learners can score different aspects of the learning on a scale, by ticking the box corresponding to their choice. You might offer five choices. --------------- ---------- ---------------- ---------- --------------- Very Poor Poor Acceptable Good Excellent --------------- ---------- ---------------- ---------- --------------- But you can apply some psychology here. If you have an odd number of possible ratings as we have here (5), there is a tendency for learners just to choose the middle one. You can try to force them to make a more measured evaluation by having an even number of possibilities which makes them positively choose. ---------- ---------------- ---------- --------------- Poor Acceptable Good Excellent ---------- ---------------- ---------- --------------- These four categories can be represented by numerical values, say zero to three. - Poor = 0 - Acceptable = 1 - Good = 2 - Excellent = 3 Doing this, allows you to carry out some simple statistics, such as finding the average response for the whole group of learners and to compare the overall response of different groups. #### Feedback statistics Perhaps it's easier to see this in an example. Imagine you have a group of 10 learners. Their answers to the questions on the feedback form are: - Poor -- 0 responses - Acceptable -- 3 responses - Good -- 6 responses - Excellent -- 1 response This converts to a total of 18 (0x0 + 3x1 + 6x2 + 1x3). Dividing 18 by the number of learners (10) gives an overall score of 1.8 for the group as a whole, equating to Good. Another way of looking at this data is to produce a graph. image:feedbackstats.png You can then make a visual comparison of the results for each question. #### Unstructured feedback Of course you should allow the learners to provide some feedback on the form which is not structured by your questions. It is important to leave space for them to make comments, either throughout the form at appropriate questions or at the end under 'any other comments'. To analyse these, you should simply list the actual responses and note any duplicated points of view. There are a couple of other points to note apart from question design if you are to motivate your learners to make a good job of completing the form Before proceeding, note down anything else that you can think of that should be in the feedback form design if it is to be successful in its purpose. #### Essential elements of feedback form design Well, for the form to be successful, the instructions must be easily understood and it should be easy to fill in. It should also be quick for the learner to complete. This all suggests a short questionnaire, one or two sides maximum with a limited number of questions having straightforward possible responses #### Simple feedback form You can find many examples of simple course feedback forms on the internet #### Commercial software and websites You may also like to explore using commercial software such as SurveyMonkey which facilitates design of survey forms and collation and analysis of results via the Internet. See it at <http://www.surveymonkey.com> There are many Internet websites offering advice on feedback form and questionnaire design. One problem is that many of them are aimed at professional researchers and thus too detailed. However, you may still benefit from looking at some of these sites, as the basic principles of questionnaire design are the same, regardless of the subject area being researched. Here are some suggested sites. - <http://www.sysurvey.com/tips/wording.htm> - <http://www.statpac.com/surveys/question-qualities.htm> ### Assessing success of learning approaches The diagram shows the training cycle. It represents a continuous process of: - Identification of training needs - Design of the training and learning programme - Delivery of training and learning programme - Evaluation of training and learning programme For more information on the training cycle see: <http://mournetrainingservices.blogspot.co.uk/2009/06/training-cycle-explained.html> You have carried out the first three stages and are now about to carry out the fourth with the help of the feedback on the learning experience coupled with evidence on learner progress. In particular, the feedback will be used to assess the effectiveness of the design and delivery of the programme. This will feed into revision of those aspects of the learning programme which were judged to be less than satisfactory. With a further check on the identification of the needs and the re-design of materials and delivery, a cycle of continuous improvement is established. You have essentially two sources of information for your evaluation: - the evidence of learner progress - the feedback on the quality of the learning experience. Both are important and there are definite connections between the two. For instance, there could be a general reduction in learner progress not related to content and delivery issues but due to the learning taking place in a room which is always too hot resulting in the learners experiencing discomfort. #### Learner progress In analysing the learner progress, in order to create improvements, you must look for trends. The first time you deliver the training to a small group, poor performance from one learner may affect your results disproportionately. Over time and a large number of learners, this random effect diminishes. So you are looking for the particular topics and outcomes where a significant number of learners have difficulty. Of course 'a significant number' is a matter of opinion. But let us say that, if out of a group of fifteen learners, three had a difficulty with one topic, while excelling at all the other topics, then we would say that is significant. So you need to look for these parts of the learning and revisit the design of those parts. #### Learning experience Most of the feedback will have been converted into a set of averaged numerical data representing the learner group as a whole. You now have to interpret this data. Broadly speaking, you are having no real problems if the scores hit a point somewhere a bit above the middle value. You cannot expect every learner to think that everything is perfect. On the other hand, remember that most people tend not to give low scores unless there is a real problem. Of course different learners will have different expectations. However, again the hope is that they will apply the same expectation level to each of the facets of the learning experience and this variable will average out over all the questions and learners. There is one danger in using the average and getting a middling score. That is, if out of a group of, say, twenty learners, ten score highest and the other ten score lowest. This gives the appearance of a just acceptable result with no great worry. A score of 50% for the learning environment could be due to one side of a room being too cold. A score of 50% for relevance of course content could be due to a group of 20 where 10 thought the training was pitched at the ideal level and 10 who found most of the content already familiar. So remember, you have to look at both the average score and the spread of scores across the group of learners. #### Looking for trends Regarding 'Any other comments', you are again looking for trends. If the same type of comments comes up three or four times out of a group of fifteen learners, then you need to address it. When you are delivering training to colleagues within your own organisation, remember that you need not be completely reliant on written feedback forms. Most of the learners will be willing to provide informal feedback and suggestions for improvement orally. You should also consider when to gather feedback. It is useful to gather opinions immediately after the conclusion of the training, when the content and delivery are fresh in the learners' minds. This can be supplemented by further feedback at a later date, if you wish to explore how useful the training has been to the learners in their workplace situation.
# Applications of ICT in Libraries/Digital Culture - Online Communication ## Digital Culture - Online Communication This is the first of two units that are relatively new additions to the Application of ICT in Libraries course. This session will explore the new digital literacies that you need to develop to be active users of Social Media tools and you will also get the chance to communicate online using a number of these services. The full course materials are hosted for registered students on the Application of ICT in Libraries pages on Moodle. This module will enable you to dip into new social media tools and explore their potential for supporting library services, your users and also your own interests. You learning outcomes will include: - What is social media? - What are the new digital literacies information professionals and our service users need to develop? - How do I facilitate and take part in a conversation on a forum? - How can I collaborate with my colleagues or manage a team online? - What tools can I use for professional networking? - How and why should I use a blogging tool? - What are virtual communities? ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="40"} Each learning outcome has a series of short activities that you will participate in with your class group. The tutor will deliver one face to face class session in North Wales and South Wales and the remainder of the time will facilitate the course online. This is a practical module that uses social media to explore social media - you have permission to play!
# Applications of ICT in Libraries/Digital Culture - Online Collaboration ## Digital Culture - Online Collaboration This is the second of two units that are relatively new additions to the Application of ICT in Libraries course. This session will explore the new digital literacies that you need to develop to be active users of Social Media tools and you will also get the chance to communicate online using a number of these services. The full course materials are hosted for registered students on the Application of ICT in Libraries pages on Moodle. This module will enable you explore more fully the collaborative nature of social media and work within a group to complete all the learning outcomes. You learning outcomes will include: - Exploring virtual communities and how the concept of \'community\' changed with the spread of social media - Using a forum to facilitate professional discussions - Using collaborative documents and cloud computing to complete a group project - Exploring the potential of social networking for continuing professional development - Developing, editing and publishing a collaborative blog - Meeting, collaborating and exploring with your group in a virtual world ![](A_Cap_Digital.svg "A_Cap_Digital.svg"){width="40"} Each learning outcome has a series of short activities that you will participate in with your class group. The tutor will deliver one face to face class session in North Wales and South Wales and the remainder of the time will facilitate the course online. This is a practical module that uses social media to explore social media - you have permission to play!
# Chess/Arranging The Board \| \|= 8 \|rd\|nd\|bd\|qd\|kd\|bd\|nd\|rd\|= 7 \|pd\|pd\|pd\|pd\|pd\|pd\|pd\|pd\|= 6 \| \| \| \| \| \| \| \| \|= 5 \| \| \| \| \| \| \| \| \|= 4 \| \| \| \| \| \| \| \| \|= 3 \| \| \| \| \| \| \| \| \|= 2 \|pl\|pl\|pl\|pl\|pl\|pl\|pl\|pl\|= 1 \|rl\|nl\|bl\|ql\|kl\|bl\|nl\|rl\|= a b c d e f g h \|Initial position of the chessboard}} ``` Before starting the game, it\'s very important to arrange the board in the right manner. The 1 - 8 horizontal squares are called \"ranks\", and the vertical ones are called \"files\". Your chess board is an 8×8 board. Place the board in such a manner that the bottom right hand corner on your side is white (\"White on the right\"). On that white square, place the Rook (known also as the \"Castle\") and place the other Rook on the bottom left corner. Next to the Rooks, place the Knights, followed by the Bishops. Wrong placement of the Queens is a common mistake. While arranging these pieces, make sure that the black Queen goes on a black square and the white Queen goes on a white square (\"Queen on her own color\"). The King then goes on the square next to the Queen. It is very important that you place these two pieces properly. Any game found to be set up incorrectly, i.e., King on its own color, will result in the game being voided and a restart called using the same colors. Fill the next rank with your eight pawns. You\'re ready to play! {{-}}
# Chess/Playing The Game Chess, unlike many other games, does not involve direct chance such as the roll of a dice or which card is drawn. The outcome completely depends on the decisions of the players. However, because of its vast complexity, the far-reaching consequences of some decisions are practically unforeseeable. One player (\"White\") has the white pieces while the other (\"Black\") has the black pieces. Sometimes the colors are not black and white (for instance, light and dark, or yellow and blue), but they generally contrast each other. In friendly games the choice of colors can be made by any method, such as flipping a coin. If there is no coin at hand, another typical way of deciding would be to conceal a black piece in one hand and a white piece in the other and ask one\'s opponent to select a hand. The colored piece selected will be the opponent\'s color. In competitive games the players are assigned their colors. ### Order of play Once all the pieces have been arranged, White (or the lighter color) makes the first move. White always makes the first move; this is important for notation, and any chess player will insist upon it. After White has made the move, Black will then make a move. The gameplay will continue in alternating fashion, White making a move, followed by Black. ### General movement rules - A move consists of moving a single piece, in accordance with its rules of movement, to a square that is unoccupied or occupied by an enemy piece. A player may never move a piece onto a square already occupied by another of his or her own pieces. - Exception: There is a special move called \"castling\" where two pieces, a rook and the king, are moved; see below. - If a piece is moved onto a square occupied by an enemy piece, the latter piece is removed from play and the first piece replaces it. The removed piece is said to have been captured or taken. - Exception: In en passant capture, a pawn moves to an unoccupied square but still captures another pawn \"in passing\"; see below. - Most pieces move and capture opponent pieces in the same way. - Exception: The pawn has separate rules for moving and capturing opponent pieces. - Most pieces may only make a move to a non-adjacent square if all the intervening squares are vacant (pieces may not \'jump over\' other pieces). - Exception: The knight can move to any suitable final square regardless of occupants of other squares. - Exception: In castling, a king and a rook jump over each other. - No player may make a move that leaves their own king \"in check\" (see below). - The player must always make a move when it is his or her turn. In other words, he or she cannot choose not to make a move. If no legal move is possible the game ends in a draw (see below), except when the king is in check - this is called checkmate, and is usually how the opposing player wins. Also, when a pawn moves to a square at the opposite end of the board, it becomes a different piece (pawn promotion); all of these exceptions are covered below in more detail. ## The board Traditionally, the game is played on a board of 64 alternating black and white squares turned with a white square to each player\'s near right-hand corner. \"White on right\" is a helpful saying to remember this convention. The light and dark squares on the chessboard and the light and dark chess pieces are traditionally referred to as \"white\" and \"black\" respectively, although in modern chess sets almost any colors may be used (as long as they are not the same colors.) The horizontal rows of squares are called ranks and are numbered 1-8; the vertical columns of squares are called files and given the letters a-h. This way any single square can be easily identified by its rank and file, making it possible to record games by writing down the starting and ending position of the piece that moves every turn. A chess diagram is always printed from the White player\'s perspective. {{-}} ## The pieces The movement of the individual pieces is described below. In all the board diagrams shown, the squares to which the piece in question can move are indicated with x\'s. ### Pawn ![](Chess_pll44.png "Chess_pll44.png") Pawns can move one square straight forward, or optionally and on their first move only, two squares straight forward. The pawn is the only piece that can\'t move backwards. This piece is worth 1 point. {{-}} #### Capturing Pieces The pawn can move one square diagonally forward to capture a piece, but cannot capture a piece by moving straight forward. For this reason, two opposing pawns on a file may become blocked by each other. In the first diagram below, legal capture moves for the white pawn are indicated with black circles. To capture means to displace a piece, meaning, to replace the captured with the capturer. In the second diagram below the White pawn is prevented from moving forwards by the Black pawn immediately in front of it (in the d-file) which it cannot capture, but it can capture the adjacent Black pawn by moving diagonally forward as seen in the last diagram. The pawn is the only piece that moves and captures differently. {{-}} ### Knight ![](Chess_nll44.png "Chess_nll44.png") The knight has a unique move that allows it to flank the other pieces. The easiest way to describe this move is that he moves to a square of the opposite color from the one he\'s on that is exactly two squares away from him. This piece is worth 3 points. {{-}} Another way to visualize the move is this: of the 16 squares that are 2 away from a knight he reaches the 8 that are of the opposite color of the square he\'s on and the other 8 can be reached by a queen where she on his square. {{-}} {{-}} It is important to remember that the knight moves in a straight line like all the other pieces, it\'s just along lines of movement no other piece uses. Consider this comparison: A queen moves ordinally along the ranks and files - North, East, South, and West on a compass rose; and she also moves diagonally - Northeast, Southeast, Southwest, and Northwest on a compass rose. The knight moves along the wind lines of the rose - North by Northeast, East by Northeast, and so on. These lines pass between the squares adjacent to the knight and pass through the middle of the squares that are one square away from the knight. The knight moves to the first square its line of movement passes through the middle of, so like the King the knight has eight squares he can move to when he is near the center of the board. Since the knight is moving between the squares adjacent to him pieces do not hinder his move whether they are allied or enemy. #### Capturing Pieces The knight captures any opponent\'s piece that occupies a square it can move to by removing that piece from the board and placing the knight in that square. An important consequence of the knight\'s use of wind lines is that it can attack (that is, threaten to capture) pieces without being threatened in return so long as they are not also knights. The reverse is also true - pieces attacking a knight are never threatened by it. {{-}} ### Bishop ![](Chess_bll44.png "Chess_bll44.png") The bishop can move any number of squares diagonally. The bishop may not jump over any piece of either color. The bishop is restricted to the color of squares on which it began the game. Each player starts out with one light-square bishop that moves on the light colored squares, and one dark-square bishop that moves on the dark colored squares. In the diagram below, the bishop stands on a light square and can only move to other light squares. This piece worth 3 points. {{-}} {{-}} #### Capturing Pieces The bishop captures any opponent\'s piece that it encounters during the movement described above, and then occupies the captured piece\'s square. In the diagram above the bishop may take any of the black queens. Notice that bishop may not move (jump) to squares behind or capture pieces hiding behind the queens. ### Rook ![](Chess_rll44.png "Chess_rll44.png") The rook can be moved any number of squares horizontally or vertically, but not diagonally. Like the bishop, the rook cannot jump over any pieces, except for \"castling\".This piece is worth 5 points. {{-}} {{-}} #### Capturing Pieces If the rook attempts to occupy a space already occupied by an opponent\'s piece, it captures the piece. In the diagram above the rook may take any of the black queens. ### Queen ![](Chess_qll44.png "Chess_qll44.png") The queen is the most powerful piece, being able to move any number of squares in any lateral or diagonal direction. It is best described as the combination of a rook\'s and bishop\'s movement capabilities.This piece is worth 9 points. {{-}} {{-}} #### Capturing Pieces The queen captures any opponent\'s piece that it encounters during the movement described above, and then occupies the captured piece\'s square. In the diagram above the queen may take any of the black queens. ### King ![](Chess_kll44.png "Chess_kll44.png") The king can move one square at a time in any direction, as long as doing so does not place himself in check (see below). This piece is worth ∞ points, because if you lose the king, you lose the game. (Note that the king would be 3.5 points as an attacker/defender.) {{-}} {{-}} #### Capturing Pieces The king may capture any opponent\'s piece adjacent to it, as long as doing so does not place himself in check (see below). In the diagrams above the king may take any of the black knights. #### Check The king is the most important piece belonging to each player, though not the most powerful. If a player moves a piece such that he threatens to capture his opponent\'s king in the next move, that king is said to be in check. If a player\'s king is in check, he must immediately remove the check by moving the king, blocking the check with another piece, or capturing the checking piece. In the diagram below black\'s rook has checked the white king. White may avoid the check by moving the king one step sideways, blocking the check by putting the rook between the attacking black rook and the white king, or capture the black rook using the white bishop. Other normally legal moves, like moving one of the pawns, are illegal in this position since they will not remove the check. In a friendly game, a check is usually announced by saying check after the move is completed. {{-}} #### Checkmate If the king is placed in check and can not escape, it is said to have been checkmated (or \"mated\" for short). The first player to checkmate the opponent\'s king wins the game. Note that the king is never actually captured, since it is obliged to move out of check whenever possible (and the game ends when it is impossible). In the diagram below white has no options to escape the check from black\'s rook, he is therefore checkmated. {{-}} #### Special Restrictions --- Avoiding \"Self-check\" Players may not make any move which allows their king to be captured in the next move, i.e. places their own king in check. Thus two kings may never occupy adjacent squares, since they would have put themselves in check by moving there. This is called the \"opposition\" and is indispensable when, for instance, you are using a queen or rook to checkmate a king. The white king in the following diagram cannot move upwards or to the left since it would be in check from the bishop, or diagonally downwards which would leave it adjacent to the black king. Also, as no piece is threatening it if it fails to move, the king is not currently in check. Similarly, the black king cannot move diagonally upwards as that would put it next to the White king. {{-}} The diagram below shows a position where the white bishop\'s movement is restricted by the same rule; the bishop can not be moved since the move would let black capture the white king in his next move. The white king on the other hand may move to any of the adjacent squares. {{-}} ## Special Moves #### Pawn Promotion If a pawn makes it to one of the eight squares along the far edge of the board from their initial position, the pawn is \"promoted\". Upon reaching the far rank the player exchanges the pawn with either a queen, a rook, a bishop, or a knight. The player\'s move ends when the new piece occupies the promoted square. The new piece need not be a previously captured piece. Thus a player can have more than one queen, and more than two rooks, bishops or knights on the board. The player may never have more than one king, since the pawn can not be promoted to a king. In theory it is possible to get up to nine queens, or ten rooks, bishops or knights since there are eight pawns to promote. In practice however the pawn is usually promoted to a queen, since it is the most powerful piece, and it is rare for a player to have more than two queens on the board. If an extra queen is not at hand, an upside-down rook is usually used as a substitute. {{-}} #### Castling !Kingside castling: O-O !Queenside castling: O-O-O Castling is a move involving the king and either of the rooks. Castling performed with the king\'s rook is called kingside castling, performed with the queen\'s rook is called queenside castling. A castling is typically done to move the king to a protective \'castle\' surrounded by three pawns and a rook. Subject to restrictions detailed below, a player may move his king two squares towards the rook, and subsequently, on the same turn, move the rook adjacent to but on the opposite side of the king, (onto the square over which the king has just passed). The restrictions specific to castling are: 1. Neither the king nor the participating rook may have moved previously in the game 2. The king must not be in check at the start of the move, though it may have been in check previously in the game. 3. The square over which the king passes must not be under attack (\'in check\') from an enemy piece. (This would expose the king to a \"check\" in passing.) The rook(s) may be under attack, or the queens\' rooks may pass through an attacked queens\' knight square. 4. The king must not be in check at the end of the move. (Also applies to all normal moves.) 5. The squares between the king and rook must be vacant. The diagrams below show examples of positions where castling is not legal. {{-}} Note that the king must be the first piece moved and it must be moved two squares before it is released. If the rook is touched or moved first, then the king must stay where it is. This rule mainly applies in \"strict rules of chess\" where if a piece is touched, it must be moved. Touching the rook first indicates a rook only move, while releasing the king after one square indicates a king only move. Moving the king two squares is not a legal move by itself, and indicates a castling move. {{-}} #### En passant capture En passant is French for \"in passing\"; you capture an enemy pawn as it is passing you. When a pawn on its first move advances two squares onto the same rank as an opposing pawn on an adjacent file, this opposing pawn may, on that player\'s next move only, capture the advancing pawn as though it had only moved one square (provided the move is otherwise legal). The pawn\'s ability to move two squares on their first move was a relatively late addition to the game of chess. En Passant was introduced to prevent abuses of the new rule. In the following example, the Black pawn advances two squares, and is captured by the White pawn which moves diagonally forwards and to the right (as if the Black pawn had moved only one square forward and been there). This move is only allowed on the turn in which the option is presented. {{-}} ## Initial position In the initial position each side has eight pawns, two rooks, two knights, two bishops, a queen and a king arranged as shown in the diagram below. Note that the only pieces on either side which can initially move are the pawns and knights. Beginners often set up the board incorrectly; it is a complex position to remember. The following mnemonics may help you remember where the pieces go. - White on the Right It is important that the bottom-right-hand square is light-colored. - Knights live in castles One knight is placed next to each rook (rooks look like the towers of a castle, and are sometimes \[incorrectly\] even called castles.) - Queens on their color OR The dress matches the shoes The White Queen goes on a White Square, Black Queen goes on a Black Square - Bishops are advisers to the Royalty Bishops surround the King and Queen. - White King on the Right From the White Player\'s perspective, both Kings are on the right, and from the Black Player\'s perspective, the Kings are on the left. If the ranks and files are printed on the board, the following rules may be helpful: - White\'s pieces should be placed on the 1st and 2nd rank, and Black\'s pieces should be placed on the 7th and 8th rank. - The Queens should be positioned on the d-file (D for Dame). {{-}} ## Conclusion of the game Play continues to alternate between White and Black until one of the following outcomes is reached: ### Winning and losing - One player\'s king is checkmated. The game is lost by that player. - In a competitive game, one player runs out of time. The game is lost by that player (with two important exceptions, see draws below). - One player resigns, which is equivalent to quitting the game. A player may resign on either his or his opponent\'s turn. Resignation is often symbolized by the resigning player tipping over his king. ### Draws - The player to move has been stalemated, meaning that he has no legal move and is not in check. - Both players agree to draw the game. Either player may offer a draw to the opponent upon completion of his move. If the offer is accepted, the game is drawn. If the offer is rejected, the game will continue. - A player can claim a draw with if any of the following are true: - If the exact same position occurs or will occur three times with the same player to move, the player on move may claim a draw by threefold repetition. Note that the same set of moves must be available for each player (including castling and en passant). - No pawn has moved and no piece was captured in the last 50 moves. - The opponent does not have sufficient material to checkmate him by any legal sequence of moves. - Both players have run out of time in a competitive game. - One player has run out of time in a competitive game, but the opponent does not have sufficient pieces to checkmate him by any legal sequence of moves. {{-}} The diagrams above shows example of some of the draw rules: - Stalemate: Since black can not move the pawn or the king without placing himself in self-check, the game results in a stalemate. - Threefold repetition: Black has checked white, and can continue to check white forever by moving the rook back and forth between f2 and f1. The same position will thus occur again and again. - 50 move rule: White has material advantage and enough material to mate, but if black plays correctly black will use his bishop to avoid being mated forever. - Insufficient mating material: White has material advantage, but not enough material to mate. ## Chess Etiquette Generally, chess games at tournaments are conducted under the following rules: - Touch-move rule - If a player touches his own piece, he must move it, and if a player touches an opponents piece, he must capture it (unless the capture is not possible). If he releases a piece on a square, the move is completed and can\'t be taken back. If you need to center a piece on its square, it is traditional to say j\'adoube (I adjust). - Be silent when your opponent is on the move - You can only adjust pieces, offer a draw, or claim a draw when it is your turn to move. A friendly game may be played in any way that is mutually agreeable. Generally it is considerate to avoid distracting your opponent. ## Glossary - Capture - To move one\'s piece into the same square as one of one\'s opponent\'s pieces. The opponent\'s piece is removed from the board. - Check - The king is \'in check\' when it is being attacked by an enemy piece. - Checkmate - The player whose turn it is can make no legal move to get his king out of check. - Stalemate - The player whose turn it is can make no legal move, but the king is not in check. es:Manual de Ajedrez/Iniciación del juego it:Scacchi/Le regole del gioco ms:Catur/Bermain nl:Schaken/Spelregels pt:Xadrez/Regras ro:Şah/Reguli de bază zh:国际象棋/规则
# Chess/Notating The Game Notating chess games is important to any chess student, since it allows them to review their strategy and that of their opponent, to read of classic chess encounters, and follow how the game developed. Further, chess puzzles are often set in magazines, newspapers and online, and their solutions are notated; for an example, see The Times Chess. ## Algebraic notation A very common nomenclature for chess games is algebraic notation. There are several older systems of notation, but these are less common. In algebraic notation, we use - R for a Rook; - N for a Knight; - B for a Bishop; - K for a King; - Q for a Queen; - no letter for a Pawn. Sometimes a pictorial language-independent notation is used, in which a picture of a horse might represent a Knight, and so on. Each square on a chess board is given by a coordinate, much like a map or a planar graph. The ranks (rows) are indexed with Arabic numerals 1 through 8, and the files (columns) are indexed with Latin letters "a" through "h." A square's coordinate is denoted as its file index followed by its rank index. For example, in the board below, black's King is on the square d5. If black moves his King to, say, d6, the move is notated as Kd6, i.e. the King has moved to square d6. If more than one piece of the same type could have moved to the square to which the piece was moved, then the file of the piece prior to its move should come in between the piece\'s symbol and the coordinates of its destination (i.e., Qee7.) If necessary, the rank it was on may also be added, (i.e., Qe6e4.) Moves in which a piece is captured, a King put in check, or checkmate have special notations. - If a piece is captured, a cross (x) is inserted just before the destination square. Thus, if the capture is done by a Pawn, the cross is preceded by the column the Pawn occupied prior to the capture. - If the King is put in check, the move\'s notation is followed by a plus sign (+). - If the King is put in checkmate, the move\'s notation is followed by a hash or double plus signs (#\'\'\",++\'\'\',) or the word \"mate\" or \"checkmate.\" ### Annotation shorthand Annotation shorthand is not a notation system. Rather, it is a system of symbols for the player or annotator to add his descriptions or comments. A player or annotator notating a game might wish to highlight an excellent move, question a bad one, or indicate which player he thinks has the advantage. - If a move is followed by an exclamation mark (!), the player/annotator is surprised by the move\'s quality. - If a move is followed by a question mark (?), the player/annotator suspects the move may have been poor. - If a move is followed by an exclamation mark and then a question mark (!?), the move interests the player/annotator, though it may be sub-optimal. - If a move is followed by a question mark and then an exclamation mark (?!), the player/annotator fears that the move may be conclusive. Repeating a symbol (e.g. !! or ??) adds emphasis. Results are written as white\'s score followed by black\'s score. For example, 1--0 indicates that white won, and 0--1 indicates that black won. In the case of a draw, the result is ½--½. There are some additional symbols for the player/annotator to note his thoughts on the game in general, rather than on any particular move. - An equals sign (=) indicates positional equality between the players. - A plus-minus sign (+/--) indicates that white is considered to have the advantage. - A minus-plus sign (--/+) indicates that black is considered to have the advantage. ## Ambiguity Sometimes algebraic notation can be ambiguous---that is, two pieces of the same designation can move to one square. For example, a player might be able to move either of his Rooks to the same square. In these cases, it is essential to specify which piece was moved. The precise move is specified by designating the file (column) that the piece moved from, before the move\'s final co-ordinate. For example, Nd2 indicates that a Knight moved to d2, but Nbd2 indicates that the Knight that was in column b moved to d2. If a piece\'s file is not enough to precisely specify the move, then its rank is used instead. If neither is enough on its own, both are used. ### Special moves Some special moves are tricky to write in algebraic notation, and must have their own notation. - Castling King-side is written O-O. - Castling Queen-side is written O-O-O. - En Passant (or En Passe\") (French for \"In passing\") capture is written as if the captured pawn only moved one square. The notation may be followed with e.p. or ep to clarify that the capture was done En Passant. - If a Pawn is promoted, the Pawn\'s initial move is written, followed by an equal sign and then the shorthand for the new piece; for instance, e8=Q. Any additional nomenclature or annotation is written after the shorthand for the new piece (such as c8=Q+ if a Pawn promoted to a Queen on c8 places the opposing King in check.) ## Sample game in algebraic notation If you have familiarized yourself with algebraic notation, consider this short sequence of moves. Try to follow the game by looking at the moves in algebraic notation, and the boards. The game has begun, and is nearing the end. White is to move. White decides to move his Bishop from d3 to c4, to check black\'s King. This is white\'s thirtieth move. So in algebraic notation, we write - 30. Bc4+ Since only one Bishop could move to c4, the Bishop\'s initial position was not specified. The + indicates the check. White\'s Bishop is now, unfortunately, in the Queen\'s line of fire. Black decides to capture it. So for black\'s 30th move we write - 30\... Qxc4 The x signifies that a piece has been captured. When black\'s move is written separately from white\'s, an ellipsis (\...) is placed between the number and the move. The ellipsis indicates that white\'s move has been omitted. The board now looks like this: White is in trouble now, and decides to flee to f2. His move is - 31. Kf2 If black checks white\'s King, by moving his Queen to c2, his move is - 31\... Qc2+ ## Descriptive Notation An older form of notation you will run into quite frequently is Descriptive Notation. It is useful to know because older books use it. In this form, instead of the files being a, b, c etc., they are Queen rook (QR), Queen Knight (QN), Queen Bishop (QB), Queen (Q), King (K), King Bishop (KB), King Knight (KN) and King Rook (KR). The ranks are labelled from your point of view so that the square e4 (in algebraic) is White\'s K4 and Black\'s K5. To record the moving of a piece, you write the piece, then a dash, (\"-\") which means \"moves\", or \"moves to\" and to where it moves. 1. P-K4 means move a Pawn to the 4th rank in the King\'s file. N-Q-B3 means you move your Knight to the third rank in the Queen\'s Bishop file. For a capture, you specify the piece taking, and the piece to be taken. QRPxN means Pawn in the Queen Rook file takes Knight. Excessive notation is left out so that if there is only one way a Pawn could legally take a Knight, the move is recorded as PxN. Note that if a piece is specified to be on the King\'s or Queen\'s side of the board, that is the side it is on now, NOT the side it started out on. In rare occasions the move will still be ambiguous when, for example, both Knights can make a particular capture and both of them are on the same side. It would then be necessary to insert a \"/\" which means \"on\". For example: N/3XP (for the rank) or N/BXP (for the file). In order to compare the two systems, we could look at the same game in both algebraic and descriptive notation in full (1, 3, 5) and abbreviated (2, 4, 6) notation. +--------------------+-------------------------------------------------+ \| Algebraic \| Descriptive \| +====================+=================================================+ \| 1. e2-e4 e7-e6 \| 1. PK2-K4 PK2-K3 \| \| 2. d4 d5 \| 2. P-Q4 P-Q4 \| \| 3. Nb2-c3 Bf8-b4 \| 3. NQN1-QB3 BKB1-QN5 \| \| 4. Bb5+ Bd7 \| 4. B-QN5ch B-Q2 \| \| 5. Bh3xd7+ Qd8xd7 \| 5. BKR3xQ7ch QQ1-Q2xB \| \| 6. Ne2 d3xe4 \| 6. N-K2 PQ3xPK4 \| \| 7. 0-0 \| 7. 0-0 \| +--------------------+-------------------------------------------------+ : 1.Note here that since only one Bishop can move to QN5, it is unnecessary to specify which Bishop moved to that square. : 2.Check is indicated by \"ch\", or \"+\", and \"++\" for the uncommon but not entirely rare double check, and \"+mate\" or \"+++\" for checkmate. ## Coordinate Notation A different type of notation uses only the squares that the pieces were on to denote movements; the dash \"-\" is inserted to denote \"moves to\". For example, to denote the earlier 7 moves, the following notes are shown: 1. e2-e4 e7-e6 2. d2-d4 d7-d5 3. b1-c3 f8-b4 4. f1-b5+ c8-d7 5. b5xd7+ d8xd7 6. g1-e2 d5xe4 7. 0-0 or 0-0-0 ## ICCF numerical notation ```{=html} <div style="float:right;"> ``` ```{=html} </div> ``` A move is denoted by the file (1 to 8) and rank (1 to 8) of its starting square followed by its destination square (from 11 at the White Queen's Rook square to 88 at the Black King's Rook square). \"1. e4\" is denoted as \"1. 5254\" in ICCF notation. Unlike other notations, ICCF notation does not make apparent when castling, check, checkmate, and capture took place (castling King side is 5171 for white and 5878 for black). Pawn promotion necessitates a fifth number specifying the new piece (1=Queen, 2=Rook, 3=Bishop, 4=Knight). This notation is considered to be international in that there is no dependency on piece names or specific alphabets. However this notation still depends on Arabic numerals. es:Manual de Ajedrez/Anotando un juego it:Scacchi/Annotazioni di gioco ms:Catur/Mencatat permainan
# Chess/Tactics ## Guarding When one of your pieces is placed so that it attacks a square occupied by another of your pieces, the former is said to be guarding the latter. When your opponent captures the guarded piece, you can recapture with the guarding piece. Note that if a guarding piece is pinned to your king (see below for a description of pins), it can only guard other pieces against capturing by the enemy king, but not from other enemy pieces, since it is unable to move or capture. ## Batteries Batteries are formed when two or more pieces work together. The most common kind of battery is the doubling of rooks on a file. Other batteries can be formed by rook-queen, bishop-queen, two knights or a bishop-pawn. A triple battery can be constructed with the queen and both rooks. This is known as Alekhine\'s gun (diagram at right) and can be extremely dangerous. It is often advantageous to place the queen behind one or both rooks as it is a more valuable piece. ## The Exchange In almost any game, a player will have the opportunity to capture one of his opponent\'s pieces in exchange for sacrificing or losing one of his own pieces. This should however NOT be done for its own sake! Initiate an exchange only when it benefits you. Benefits can include, but are not limited to: - Material advantage - Exchanging one of your pieces for a more valuable opponent\'s piece (e.g. exchanging a bishop for your opponent\'s Queen). - Doubling pawns - Take when taking back means the doubling (or tripling) of your opponent\'s pawns on the same file. - Opening up the king\'s defenses - Take when taking back means moving a pawn that exposes the king. - Removing a defender - Take when the piece being taken is providing an essential service for the opponent. - Blunting an attack - When you are being attacked, often a well timed exchange will leave your opponent with too few pieces to keep up the attack. - Gaining space - In a cramped position, having more pieces can actually be a disadvantage because the pieces get in the way of each other. If your opponent has a space advantage, exchanging pieces can lessen the advantage and make the resultant position less confining. - Improving a material advantage - if you are ahead material, exchanging pieces will usually benefit you (note - pieces, NOT pawns). Similarly, if you have an extra pawn, trade pieces that may otherwise be used as a sacrifice to prevent pawn promotion. - Forcing checkmate - If you are able to force a checkmate by exchanging pieces, you should always take the exchange, even if the exchanges seem poor (e.g. sacrificing a Queen for a bishop). Note that a forced checkmate is one where there is no way for your opponent to prevent the checkmate. - Threatening checkmate - Sometimes, you can propose an exchange where you can force a checkmate if your opponent accepts the exchange. That is if your opponent captures your piece after you capture one of their pieces, you are then able to force a checkmate. - Preventing checkmate - If you are in a situation where the only way out of a checkmate is to exchange pieces, you must make the exchange. ## Forks and Double Attacks Sometimes a piece can be in position to attack two enemy pieces at once. This is called a fork or a double attack. All pieces can fork, even pawns, but knights have a reputation for making especially vicious forks because other pieces cannot block their way because the endangered pieces cannot defend by attacking it, unless they are another knight. ### Forking with check A knight fork that attacks the king from an unguarded square is very powerful. The opponent must then move his king to safety and the other piece in the fork has no chance of escape. #### The Royal Fork A royal fork is one involving both your opponent\'s king and queen. In the example shown here, white\'s knight on f7 has engaged black in a royal fork. Black will be down the exchange of a queen for a knight. ### Forks do not always win material If every time you saw a fork you played it, you would be making a mistake. You have to examine the different possibilities to escape the fork. In the queen fork on the right white has just played 1.Qd4+ forking the black king and rook. However black can play 1. \...Rg7 blocking the check and moving the rook to safety (although white could play 2.Qxg7, taking the rook, black could then play 2. \...Kxg7, taking the queen; white will then have lost the Exchange and will be unable to destroy Black\'s pawn majority, resulting in a forced win for Black, a queened pawn, and a king-queen checkmate.) However 1.Qd4 is by no means a bad move. Perhaps White played 1.Qd4 in order to force black to play 1. \...Rg7 in which White can now play 2.Qd8+ (fork on king and pawn) Rg8 (forced) followed by 3.Qxa5 in which case White can push his a-pawn. Here White forked Black\'s king and rook not to win the rook but to later win a pawn by a fork, and pave the way for his a-pawn to become promoted to a queen. He might have also intended to play 3.Qf6+ Rg7 (forced) 4.Qxc6, eliminating Black\'s passed pawn. {{-}} ## Pinned pieces A pinned piece is a piece that cannot move because it would expose an attack on an important piece by one of the opposing pieces, such that the capture of said piece would result in material gain by the opponent. A great tactic is to pin the opponent\'s pieces to his king; this is known as an absolute pin. For example, take a look at the board on the right. Black just moved his dark-squared bishop to b4. The white knight is now pinned and cannot move, because moving the knight would put himself in check. White\'s only way to stop the pin is to move his king. The pawn on e4 is no longer guarded by the knight, since the knight could not move to exchange. The position diagrammed to the right shows the theme of attacking the pinned piece. White can look at this position and immediately take the rook and win an exchange. However this wouldn\'t even be the best move. If white did this then the material would be dead even; however, white has more pawn islands and it would be a very close game. Instead, white can play Ng5! The rook cannot move, and black has no way of effectively defending the rook a second time, therefore Black will eventually lose a rook. So, if you have pinned a piece, try to see if you can attack the piece again, and if a piece of yours is pinned, try to see if your opponent can attack it again. The moral of the story: if you see a good move, stop and look around for a better one. In contrast to the absolute pin, a relative pin occurs when one player\'s piece is pinned to one of lesser value than the king, such as a queen or rook. If the benefit of moving the pinned piece outweighs the loss of material occasioned by the capture of the exposed piece (for example, if a forced mate may be achieved), then the pin can be disregarded and the pinned piece moved. {{-}} ## Skewers A skewer is similar to a pin, but it is in a sense more powerful. The difference between a pin and skewer is the location of the more important piece. In a pin the lesser piece blocks the attack on the more important one, in a skewer the more important piece is attacked first and when it moves it exposes the lesser piece behind it to be hit. Black has, in a blunderous moment, placed his king on d7 in front of his queen on d8. White may now triumphantly slide either rook to d1, skewering Black\'s king and queen. Since Black cannot block the check, the king has to move, exposing the black queen to the attack of the white rook. {{-}} ## Discoveries A discovery is an attack on an enemy piece which is unveiled by moving one of your pieces. The power of discoveries is that two targets can be attacked simultaneously. If combined with a check they can be lethal. {{-}} Note that White\'s 1.Nd7+ was a double check, a type of discovered check where the piece moving also gives check. Such checks are very powerful, since the king is forced to move (both checks cannot be blocked at the same time). They are also often lethal, as in the above game. {{-}} A simpler example of a discovered checkmate is shown below. ## Removing the defender By first capturing, threatening, or pinning a piece that guards another, you should be able to capture the other piece for free. You can also remove the defender of a position. By using tactics you might be able to force a checkmate! ## Sacrifices A sacrifice is an exchange of a piece for a non material advantage: {{-}} In the first diagram, White just moved 1. Kh1 to get out of check. Black sacrifices his queen with 1\...Qg1+ for a winning positional advantage - White is in check and can not take with his king because the knight guards the queen. 2. Rxg1 - forced - this smothers the king - he cannot move because his own pieces are on every square he could go to - any check on an unguarded square now is mate. 2\...Nf2# Checkmate. This queen\'s sacrifice was an example of a smothered mate (in which a knight delivers a checkmate that is caused by the king\'s inability to move anywhere). In fact, this is a special kind of smothered mate, called Philidor\'s Legacy. {{-}} ## Zwischenzugs A Zwischenzug (pronounced \"TSVISH-en-tsoog\",) or \"in-between move,\" is one that is made unexpectedly in the midst of a sequence of moves. But not just any series of moves, one in which the player falling for the Zwischenzug feels the sequence is forced, while his opponent demonstrates to him that it certainly isn\'t! Most commonly these fall in between trades where a recapture seems to be the only proper means of play. Such in-between moves often have a surprising and pleasing effect of increasing the potency of a combination beyond the opponent\'s expectations. In Borisenkov-Mezenev (shown in the diagram to the right), black played 1\... f2, threatening to queen, which White countered with 2. Rg8, intending 3. Rf8+, and 4. Rxf1. But White resigned after the Zwischenzug 2\... Bb1! which allows Black to queen (3. Kxb1 f1=Q+ or 3. Rf8+ Bf5).{{-}} it:Scacchi/Tattica
# Chess/Tactics Exercises Chess is, of course, a game of tactics and strategy, and the tactics described in the Chess/Tactics entry are important to any chess player. The right tactics can allow you to make quick gains of material, can protect you from quick losses of material, and can, ultimately, help you to win chess games. ## Tactics Practice Good chess players, then, must practice tactics. Consider the chess boards below. In each board white can win material by force, if he chooses his moves wisely and utilizes the tactics described in the Chess/Tactics entry. Play white first in each board (unless, of course, it is otherwise stated), and force material gains for white with the right tactics. The solutions are at the bottom of this page. ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ```{=html} <div style="float:left"> ``` ```{=html} </div> ``` ## Solutions ### 1. - 1\. d5 Ne7 (White threatens knight with pawn, black moves knight, knight no longer guards b4.) - 2\. Qa4+\... (Fork tactic; queen checks king, and threatens bishop. Black must concede bishop.) ### 2. - 1.Rxd7+ Kc8 ( if \...Nxd7??, 2. Qe8#) - 2\. Rd5+ (if Re7+, Kb7 and White risks losing an exchange) Kb7 - 2\. Qc6 is also acceptable. It is followed by \...Ra7, Be6 and eventual moves that clear black pawns on the right. - 3\. Rxe5 Bd6 - 4\. Rh5, and white wins a pawn while still being able to keep pressure on black. ### 3. - 1.Rf8+ Rxf8 (\...Ka7? 2.Bxe3+ b6 3.Rxh8) (White\'s rook forks check and black\'s rook, and discovers threat on black\'s knight from white\'s bishop.) - 2.Rxf8+ Ka7 (Rook checks king. King moves diagonally.) - 3.Bxe3+ (Bishop takes knight with check, gaining a piece and avoiding a checkmate on Rg1.) ### 4. The expected solution: - 1\. Qf4; black\'s pinned knight is now en prise (thrice attacked, twice defended). - 1\. \...Ned7 defends for black (1. \...Ng6 is fruitless, as white needs simply relocate his queen, Qf5, and black is out of tricks) - 2\. e5! and we see that white\'s first move was critical, preparing his e pawn to assume the now vacant e5 square, forking black\'s knight and rook. This one is a tricky alternative: - 1\. Rf5 Ned7 (2. \... Re8? 3. Raf1 Ned7 4. Qf2!) (White adds pressure to the knight forcing a withdraw.) - 2\. Qf2 Rg8 (2. e5? Rb6 3. exf6 Qxe2) (White adds pressure to the other knight, preventing black from moving any of its defenders, and also protects the bishop. There are other responses for black, but this generates some offensive threats and is probably the best option.) - 3\. e5! Rxg5 (3. \... Nxe5? 4. Bxf6 Rxf6 5. Rxf6) (White\'s pawn move offers the most immediate reward in the impending exchange. White still has potential with 3. Bh4, but the gains, if any, will take many more turns to come to fruition. For example, 3. Bh4? Rg6 4. Rf1 Qe8! yields a situation far less favorable for white.) - 4\. exd6 Rxf5 - 5\. dxe7 Rxf2 - 6\. Kxf2 (White does not necessarily have to allow the exchange happen to completion, but since white has a material advantage such simplification of the board is only to his or her benefit.) This results in white having a bishop, a rook, and a pawn on the seventh rank versus two knights. From there, white can win a further few more pawns somewhat easily, giving a hefty material advantage. One might try the more immediate 1. c5 with the hope of 1. \... Rd5 2. Bxf6 but to do so is forgetting that 1. \... Rc6 is another response. Also, one might try 1. Bxf6 Rxf6 2. Qg7, with the idea that black cannot save both of the rooks at once, but this also does not work because of 2. \... Rxf1+. White must now play something like 3. Rxf1, which gives black the opportunity to save the rook on h8. ### 5. - 1.Qb3+ Kh7 (\...Rf7 2.Qxf7+ Kh7) (White checks king with queen. King moves away.) - 2.Rh1+ Qh5 (White checks king with rook. Black blocks with queen.) - 3.Rxh5+ gxh5 (White exchanges rook for queen!) Note the importance of white\'s knight in this exchange. It guarded f7, preventing a simple defense of the initial check with Rf7. Alternatively, if 1. \... Kh8, - 2\. Nf7+ if 2. \...Kg8, 3. Nh6+ (or Nd6+) wins the queen for a knight. If 2. \...Kh7, - 3\. Rh1+ if 3. \...Qh5, 4. Rxh5 (back to main variation) if 3. \...Kg8, 4. Nh6+ (or Nd6+) wins the queen for a knight ### 6. - 1.Nf6+ Kf8 (\...gxf6? 2.Bxf6 Nxa1 3.Rh8#) (Nf6 checks, and threatens two rooks. A naive defence of gxf6 would result in checkmate.) - 2\. Nxd7+ Kg8 (Any other move allows 3. Rh8#) - 3\. Nf6+ leaving Black in the same bind, eventually winning Black\'s other rook as well. ### 7. - 1.Rh3+ Kg8 - 2.e7+ d5 - 3.exd8=Q Rxd8 - 4.Qxc5 Bxh3 - 5.gxh3 ### 8. - 1.Rh8+ Kxh8 - 2.Qxf8+ Kh7 - 3.Qxg7# - Also 1.Qe6+ Rf7 2.Rf1 (Black\'s rook is pinned) Black cannot stop 3.Qxf7# ### 9. - 1.Rh7+ Kg8 - 2.Rcg7+ Kf8 - 3.Bd6+ (Computer give the better 3.Bh6 \... - 4.Rh8# is better and logical!) \...Re7 4.Bxe7+ (With mate following, this was what I saw and played. Bh6 is better but it might be to hard for all to find, both lead to mate) ### 10. - 1.Rxf8+ Kxf8 - 2.Qf3+ Kg8 (\...Bf4 3.Bxf4 exf4 4.Qxf4+) - 3.Qxg3 ### 11. - 1.Nf6 Qe7 (\...Bxf6? 2.Qxf6 Kg8 3.Bh6\...) \... 1. \...Qc8 gives white mate in at most 8 moves) - 2.Nxe8 to win an exchange Alternatively, - 2.Nxh7+ Kg7 3. Bxe7 to win an exchange (when black recaptures on h6 or e7 just move the other piece away) ### 12. - 1.Ne7+ Kh8 - 2.Nf7+ Qxf7 - 3.Rxf7 Alternatively, - 2.Nexc8 (Threatening back rank mate with Rf8#) if 2. \... Bxe3+ then 3. Qxe3 Other black moves that avoids mate should allow 3. Nxa7 ### 13. - 1\. \...Bh4 - 2.Qxh4 Nf3+ - 3.gxf3 Qxe3+ - 4.Kd1 Bb1+ - 5.Qxd8+ Rxd8# ### 14. - 1\. \...Bxg3 - 2.fxg3 Rxg3+ - 3.hxg3 Qxg3 - 4.Kh1 (4.Kf1 Qf3+ 5.Kg1 Rg8+ 6.Kh2 Qg2#) Qh3+ - 5.Kg1 Rg8+ - 6.Kf2 Rg2+ - 7.Kf1 Qh1# ### 15. - 1\. \...Bxb3 - 2.cxb3 Qxd1 ### 16. - 1.Qe6+ Kf8 (1. \...Kh8? 2.Rxh7+ Kxh7 3.Qxg6+ Kh8 4.Rh1# or 4.Qh7#) - 2.Rxh7 Bg7 - 3.Rdh1 or 3.Bxg6 with mate following. There are different moves Black can play, White is likely to play both Rdh1 threating rook sacrifice on h8 followed by mate and Bxg6 which is threatening Qf7#. 1.Qxd4 is also winning for White. 1. \...Ng7 2.Rxh7 Kxh7 3.Qh4+ Kg8 (3. \...Nh5? Qxh5, g pawn is pinned) 4.Bxg6 Kg8 With mate following. ### 17. - 1.Nd2+ Kc2 - 2.Nf3 (There is no way for White to avoid giving up an exchange.) ### 18. - 1.Qh5+ Kg8 - 2.Qxh7+ Kf7 - 3.Qxf5+ Kg8 - 4.Qh7+ Kf7 - 5.Rf3# (1.Qxh7? Re5 2.Rf3 Ke8 and game continues) ### 19. - 1.Nf5+ Kg8 (1. \...Kf8? 2.Rh8#) - 2.Qg4+ Kf8 - 3.Rh8# ## A Highly Tactical Position What follows is a complex board. The board arose after the opening moves 1.e4 e5 2.Nf3 Nc6 3.Bc4 h6 (Ask yourself, was h6 a bad move?) 4.Nc3 Na5 (Ask yourself, was Na5 a bad move?) 5.Bxf7+ Even an experienced player might struggle to calculate all the possible moves and their consequences. One way to improve one\'s tactical vision is to set-up this board, or indeed any board, choose an opening move, and then continuing, picking the best moves possible, and noting the success of the initial move. Consider the h6 and the Na5 moves, and note their weakness. Indeed, the Na5 move\'s tempo renders black\'s only developed piece useless, and the h6 move weakens the King\'s side and scuppers a future defensive g6 move. Black may have anticipated a Fried Liver Attack, and made a pre-emptive defense, though such an attack should threaten black. Now consider how the game might develop. Black is in check. He can take the bishop (Kxf7), but this might not be tactical. If Black moves Kxf7, there is an inevitable knight check (Nxe5). White might then play Qh5 which may be played with check. Studying the many variations, and the patterns of movement, will be beneficial for any chess player, especially once white\'s queen is active. There are many mate threats that can be created, and many guarded squares that black cannot move his king to. Here are possible scenarios. First, Ke7, where black moves his king forward, and out of check, which is discussed in some detail. Second, Kxf7, where black captures white\'s bishop, which is left as an exercise for the keen reader. :\1\...Ke7 Declining the Bishop capture 2. Nd5+ now the King is forced to capture the Bishop (or play Kd6 with no lose of material for white), 2\...Kxf7. It was bad for black to decline the sacrifice because white was able to muscle black into accepting it, and now white has an additional knight bearing down on the black king. 3. Nxe5+ Ke6 (3\...Ke8 Would lead to mate with 4. Qh5 g6 5.Qxg6#) 4. Qh5 (White now threatens 5. Qf5+ Kd6 and 6. Nf7+ winning the Black queen the following move) 4\...Qg5 (it is plausible that Black will play this in attempt to trade queens and greatly reduce White\'s attack) 5. Qf7+ Kd6 (The e5 Knight is immune from capture from the King, for two reasons. 5\...Kxe5 is met with a.) 6. f4+ forking the Queen, so long as f4 is defended by a white piece, and b.) 6. d5+, this is good because it facilitates the development of the dark square bishop, but white is likely to lose the bishop so long as the queen is protected by the h pawn. There are two ways but only 1 black queen you might say, regardless it is still good to have two ways. What this means is if white can utilize his knight and queen for different things since they aren\'t tied down to the defense of the f4 square, and the d5 knight will remain immune. That means white is more flexible and can respond to blacks defenses in more ways) 6. Qxf8+ (vacates the f7 square with tempo) Ne7 7 Nf7+ (forking the King and Queen) Black\'s position is hopeless. :\1\...Kxf7 See if you can work out what can happen here.
# Chess/Strategy ## Strategy Basics You may choose different strategies depending on what type of opponent you are playing, and what kind of player you are. Strategy starts with the opening, and continues through the middlegame, and on to the endgame. Games are considered open if the exchange of pieces have opened up files or diagonals, and closed if they have not. These games are called open or closed because there is more mobility for one's pieces in open games, and because this category usually determines the complexity of the game. Specifically, recognition of open versus closed games is important because closed games are more conducive to Knights, whereas open games see more involvement with longer range pieces such as Bishops, Queens, and Rooks. _Strategic Openings:_ If you choose to play a long-range, theoretical sort of game, you may want to choose a complex opening such as the Queen's Gambit, the Ruy Lopez, or the English. In these types of games, especially when you are playing the closed variations, you are likely to venture into close positions where positional maneuvering predominates over tactical shots. From there, you can focus on strategic elements like controlling files, pawn structure, and other long range development considerations. _Tactical Openings:_ If you are more interested in sharpening your tactical play and focusing on combinations, you may choose a more tactical opening. Some of these openings include the Sicilian Defence (especially the Dragon and the old main line of the Najdorf), the Grünfeld Defence, and the older variations of the Two Knights\' Defence. By initiating exchanges you can always simplify the game, and it will become more computational. If you don't want that to happen, you have to be very guarded and conservative. You should always be thinking about how many squares a piece controls (i.e. can attack), and which squares are controlled. In the beginning you should aim to control the center of the board. As the game progresses you may want to attack one flank, especially if the King has castled onto that side. ## Material advantage Having more valuable pieces on the board than your opponent means you have a material advantage. If your position otherwise is equal, you will be more likely to win. Since not all pieces are equal, many people use the following point system to estimate which player has a greater material advantage: - Pawn = 1 - Knight = 3 - Bishop = 3 - Rook = 5 - Queen = 9 - King = infinite (3.5 as an attack/defense strength during end game) However, a slightly more accurate system is as follows: - Pawn = 1 - Knight = 3½ - Bishop = 3½ - Rook = 5 - Queen = 9 - King = infinite These values can only be used as guidelines for the relative value of the pieces; a piece\'s value in a particular chess position must be treated on a case-by-case basis. ### Queenside vs Kingside When calculating the value of a position, dividing the board in Queenside and Kingside, it will be seen that it matters that the king is considered to be worth 3.5 points. The calculation of forces on either side will determine the stronger side. This side usually can become the attacking one, all other things considered. ### The pieces\' relative value changes over time The value of the pieces changes as the game progresses, because there is less material on the board to get in the way of some pieces. Rooks usually become more powerful because there are fewer pawns in the way, and a rook has the opportunity to control more squares. Bishops can travel great distances if unobstructed, while knights have a more local presence. So, knights shine when the board is cluttered in a closed game because they can \"jump\" over pieces whereas bishops are generally stronger in open games where they have the run of the board. ### The value of the King Assigning a point value to the King for the sake of deciding to trade the King for other pieces doesn't make sense, since capturing the King is the object of the entire game! Therefore it is customary to either exclude the King from the point value scale, or assign it an infinite value. However, keep in mind that the King has an attacking and defense capability as any other piece. The King attack and defense value changes dramatically as the game progresses. During the opening and middle game the King is a piece that needs to be protected against checkmate at all cost. Its usefulness as an attacking or defending piece is thus limited. However its strength as an attacking piece becomes greater in the endgame. In this phase of the game it is generally reckoned to be stronger than a knight or bishop but weaker than a rook. Therefore giving the King an attack or defense point value of 3.5 during the endgame makes sense. ### Knight vs Bishop Based on the point value scale above the value of the knight and bishop appears to be the same. Alternative scales have tried to assign the knight and the bishop slightly different values, usually preferring the bishop over the knight. But since the relative value of the knight and bishop is strongly related to the position, such minor differentiation provide little overall guidance. Knights are more powerful if they have a safe outpost in enemy territory - a knight on the 6th rank that cannot be attacked by opposing pawns can be as powerful as a rook in the right circumstances. This type of knight, if guarded by a pawn, is called "a home away from home". A bishop never leaves its own color, so if one of the bishops is captured, half the board is now out of reach of a bishop. So trading one bishop for a knight tends to favor the person losing the knight, who is left with two bishops. However, trading the second bishop isn\'t quite so hurtful. So trading a bishop for a bishop where one side has only 1 bishop to begin with helps the side with fewer bishops. Knights cannot cover both sides of the board at the same time, while a bishop can, so in an endgame where there are pawns on both sides of the board, the bishop is stronger. Bishops cannot attack pawns that are on the opposite color, while a knight can. Furthermore, in a game where there is a short pawn chain, a knight can stand at the head of the chain and attack the pawn supporting it, so a knight is often more effective attacking pawns as long as they are limited to one side of the board. Finally, it is possible to force checkmate with two bishops and king against a lone king, but not with two knights and king versus lone king. It is important to keep in mind what sorts of positions will benefit the pieces that you have. For example if you have 2 knights and no bishops and your opponent has 2 bishops and no knights then it would be good for you to keep the center cluttered with pawns by avoiding pawn exchanges. If you do this then your opponent\'s bishops will have hampered mobility whereas your knights can hop over the pawns. Also if you have the bishops and your opponent has knights then you should play to keep the center clear so your bishops can have more mobility. Also, this idea can help you decide on whether or not to trade a bishop for a knight or vice versa. ### More pieces are usually better Usually having more pieces is more valuable when the point value is roughly equal for both players---two bishops beat a rook, two rooks beat a queen---but this is conditioned on proper co-ordination between the pieces. It may be worthwhile to sacrifice two pieces for a rook if this results in long-term damage to the enemy\'s piece co-ordination. Usually this means tying down the extra pieces to the defense of weak pawns, so that they cannot cooperate in attacking friendly pawns. ## Compensation Material values only matter in the context of position. Compensation is a term used in chess to describe the trade off between material and positional advantage. A strong position can make up for a material deficiency. For example if your opponent has all their pawns on white squares, a black bishop is worth more than a white bishop. Typically having compensation for a piece means that an attack against the enemy\'s king or strong points cannot be repelled or may only be repelled by the enemy returning the material he is up. Often compensation can refer to having the initiative or in trapping the opponent\'s king in a vulnerable position. A pawn majority on one wing or a passed pawn can also sometimes be considered compensation for a minor piece. Generally the player who is down on material has to act quickly and avoid exchanging pieces to prevent the enemy from making his material advantage count. ## Pawn Strategy and Pawn Chains In the end game, pawns gain strength as they advance because they pose the threat of promotion, so a pawn on the 6th or 7th rank is worth significantly more than a pawn on the second rank - often as much as a piece. However, in the opening and middlegame, an advanced pawn is less likely to promote and more likely to be in need of being defended. It is also unable to defend the center and often leaves \"holes\" in your territory that can serve as outposts for your opponent\'s pieces. An overadvanced pawn is then often a liability. In the opening and middle game, pawns in the center of the board block paths and support outposts. So they tend to be more valuable than end pawns. However, in the end game, a wing pawn is usually the hardest to get to and block or capture and is therefore more likely to queen. So in the endgame, the edge pawns are often more valuable than the middle pawns (Note: this is not necessarily true in some basic pawn and king endings, where a pawn on the edge leads to only drawing options). A passed pawn has only pieces stopping it from queening, so it is considered more valuable - especially if it is protected by another pawn. ## Tempo Tempo is the effective number of moves required to reach the position on the board. Moving a piece twice to reach a position it could have reached in one results in a net loss of one tempo - moving a piece back to its starting place usually results in a loss of all its tempo - unless other pieces moved that could not have moved otherwise. Also the capture of a piece means all of the tempo it gained is lost as well. Essentially, tempo is one way of showing how many effective moves you have made. So the gain of a tempo is basically like getting a move for free. Three tempi is usually considered equivalent to a pawn in terms of advantage. Example: In the position above there have been 2 tempi played on each side, play continues with: 3. cxd5 Nxd5 4. e4 Nf6 Now white still has 2 Tempi (one for d4 and 1 for e4) while black only has 1. The captured pieces lost the tempo they had gained in moving and the knight lost the tempo it had when it captured. For argument\'s sake, lets assume play went as follows: 5. e5 Nd5 6. Bc4 Nb6 7. Qd3 Na4 8. Nc3 Nxc3 9. Qxc3 e6 Now black still has only 1 tempo (e6) while white has 6 (2 queen moves, 3 pawn moves and a bishop move). This has let white develop 2 pieces, control the center and give black a cramped position. Also, while both sides can castle kingside in the same number of moves, White can connect his rooks (position them so there is nothing between them on the back rank) 2 moves sooner than black. Chances are, white will complete development and launch an attack before black is able to. This means white will have an advantage when the middlegame is reached. ## Quality ### Active and passive pieces An active piece is one that has the potential to make a threat. A passive one is usually relegated to defending a piece. In this example, white\'s bishop on g5 is considered active, while black\'s bishop on e7 is considered passive. Piece activity depends on whether it can move and attack. A piece can be rendered passive if it is stuck protecting another piece or if it is restricted from being able to get into play by its own pawns. ### Good vs. Bad Bishops As noted above, a bishop can only travel on squares of one color. This leads to a situation wherein one bishop may be effectively blocked out of the game by the pawn structure. In general it is better to have your pawns on the opposite colored squares to your bishop. For example, if you as black have pawns on e6 and d5, your queen\'s bishop is likely to be a \"bad bishop.\" It is bad because it is hard to do anything constructive with it; developing it to g4 is impossible and \"fianchettoing\" it via b7 is ineffective since your pawn on d5 blocks any influence it may have over the centre. When one has a bad bishop there are two methods to improve the game: exchanging the offender and freeing up the game. In general it is profitable to try to exchange your bad bishop for an opponent\'s bishop or knight, as your bad bishop has little value. However, it is important to bear in mind that in the end game having two bishops is considerably stronger than have two knights or a bishop and a knight. Therefore you should always be wary of exchanging bishop for knight in situations where an endgame is likely. The other method to rid yourself of this weakness is by freeing up the game through making pawn moves. ### Overloaded pieces Overloaded pieces are pieces which defend too many other pieces and therefore cannot be considered to defend all of them at once. For example, a rook can defend up to 4 pieces, but if one is taken, and the rook takes the offending piece, 2 of the other pieces are undefended. ## Initiative The player with the initiative is the player who is making the threats to which the other person must respond. Having the initiative is advantageous because it forces your opponent to place his pieces in essentially defensive formations. A piece that is defending a square generally has less mobility (freedom of movement) than a piece attacking the same square. Having the first move, it is generally white who has the initiative in the early part of the game. Therefore trying to maintain the initiative would be prudent strategy. ## Zugzwang A Zugzwang situation occurs when any move a player makes will weaken his/her position, but he/she is compelled to move in accordance with the rules. An example of zugzwang is as follows: {{-}} White moves and wins. {{-}} 1. a4 : White moves the a-pawn, blocking the black a-pawn to move forward. Black has only one legal move; moving the black king out of the way of the d-pawn\'s path. {{-}} 1. \... Ke7 : The black king is forced to move away from his current position where he blocks the d-pawn\'s path to promotion, because he now has no other legal move to make. Since this move is not desired by Black, as he would rather keep his king on the d8 square where it stands to continue blocking the white d-pawn, Black is \"in zugzwang\". {{-}} 2. Kc7 : White\'s king continue to protect the pawn on d7 from capture, and blocks black\'s king to move back to it desired location of d8. {{-}} 2. \... Ke6 : Black can make other legal moves with the black king, but they will yield the same result. Even if Black must move the king, this is not an example of zugzwang. Keeping the king at e7 would not yield a better result for Black, since the d8 promotion square is protected by the white king. {{-}} 3. d8=Q : White gains a queen and wins the game easily. Alternatively, white can force a win by moving the king first: 1. Kd6 a4 2. Kc6(Ke6) Ke7(Kc7) 3. Kc7(Ke7) with 4. d8=Q to follow Exercise: From the same initial position but with black to move first, show that Black can force a draw by using zugzwang. Solution: 1. \... a4 2. Kb5 Kxd7 (White\'s move is Zugzwang.) 3. Kxa4 Kc7 4. Kb5 Kb7 5. a4 Ka7 6. a5 Ka8 7. Kb6 Kb8 8. a6 Ka8 9. a7 (Draw by stalemate.) ## Combining attack with defense A winning strategy in Chess often involves balancing several considerations against each other. Moves that maximize immediate material gain might expose a vulnerability or yield a difficult position as the game progresses. Similarly, material sacrifices for position may be disadvantageous if they cannot be parlayed into an effective attack. Thus, a key consideration should be balancing attack with defense. A profitable move would be one that both furthers your attack and solidifies your defense. - Yasser Seirawan in his Pro Mentor DVD. es:Manual de Ajedrez/Estrategia it:Scacchi/Strategie pt:Xadrez/Estratégia
# Chess/Basic Openings The following is an overview of the aims of an opening and some standard openings that you can try in your games. All of them are playable and should lead to reasonable games with best play. ## Aims of an opening Before looking at some of the more common openings played today it is important to consider what you are trying to achieve in the opening of a chess game. In some cases, one player will sacrifice a pawn, or in some cases even more, to accomplish the goals listed below. Such an opening is called a gambit. Development You should attempt to move your pieces away from their starting positions to squares in which they can participate more fully in the game. Obviously a Knight at c3 is more effective both defensively and aggressively than a knight on b1. Avoid moving pieces more than once in the opening as this allows your opponent time to develop another piece while you are wasting time. Also avoid moving your queen in the opening, it can too easily be chased around the board by other pieces which aids your opponent\'s development while wasting moves for you. Control the Centre The squares in the centre of the board are critical for two reasons. The first is that pieces in the centre are able to move to more squares than pieces on the edges. (Note a knight on a3 can move to only 4 squares, whereas a knight on c3 can move to 8.) Secondly, if you control the centre it is easier to move pieces from Kingside to Queenside quickly. One of the great truths in chess is that attacks along one wing are destined to fail if the centre is not sufficiently controlled. This is because the defender with a strong centre will generally be able to muster enough defence on that side and at the same time mount a counterattack in the centre and/or on the other wing. So if you plan on mounting an attack make sure you control the centre. Traditionally it was thought that the ideal situation is one where you have a pawn majority in the centre, especially with pawns on d4 and e4 (for white). However it has been shown that an equally valid strategy is to control the centre with pieces and make minimal pawn moves. The thinking is that central pawn moves often lead to permanent positions and can block attacks. \"Fianchettoing\" a bishop by moving it to b2 or g2 after b3 or g3 allows the bishop to keep a watchful eye on the centre without fixing a pawn in the centre. Castle A King in the centre of the board is open to attack. It is generally a good idea to castle your king so as to be able to defend it more easily. Some players will sacrifice material in order to prevent the enemy king from castling and to attack it ferociously due to its vulnerability. Castling also has the added benefit of bringing the rooks together on the first rank so that they are able to combine in defence and attack. Once your pieces are developed, king is safely castled, and your rooks are combined, the opening is over. Protect the King It is not always necessary although highly advisable to protect the king through castling. That being said, there are other ways to go about protecting the king than castling although they are less efficient and will often result in pins. ## King\'s Pawn Openings (open and semi-open games) ### Ruy Lopez (aka Spanish Opening) 1.e4 e5 2.Nf3 Nc6 3.Bb5 the main line continues 3\...a6 4.Ba4 Nf6 5.0-0 The move 3\...a6 works because if white plays 4.Bxc6 dxc6 5.Nxe5, Black can regain the pawn with 5\...Qd4 forking the e4 pawn and the knight. {{-}} ### Italian Game 1.e4 e5 2.Nf3 Nc6 3.Bc4 There are two key replies: 3\...Bc5, known as the Giuoco Piano (Italian for Quiet Game), and 3\...Nf6 headed to a much more involved opening called the Two Knights Defence. School children in local clubs often drift into weaker variants of the Giuoco Piano, mostly out of insufficient knowledge. A few scholastic trainers have even suggested avoiding the opening, as there are fewer crisp strategic concepts compared to many other openings. {{-}} ### Russian Game (aka Petrov Defence) 1.e4 e5 2.Nf3 Nf6 {{-}} The Petrov Defence may look like a counter-attack, and very early on this was supposed to be the idea. However, it soon became apparent that the symmetrical nature of the opening produced defensive positions. If White takes the pawn, Black should avoid taking it back because of 4. Qe2 Nd6?? 5.Nc6+ which wins the black queen. The main line goes 3. Nxe5 d6 4. Nf3 Nxe4. It is considered quite solid, and is a key defensive opening against the dangerous first move 1. e4. There are a few gambits which White can try to shift the style of the opening. The Cochrane gambit is perhaps the most dangerous. It involves a Knight sacrifice on f7. Currently not considered objectively sound, its use is psychological: White dares the opponent to spend twenty moves defending against an attack, and this pressure may cause the Black player to finally fall victim to a tactical shot. ### Philidor Defence 1.e4 e5 2.Nf3 d6 If Black wants to defend the threatened pawn with a pawn, this is the way to do it (playing 2\...f6? is plain bad, as 3. Nxe5 fxe5 4. Qh5+ is winning for White). It gives Black a solid but somewhat cramped position. The f8 bishop is hemmed in and will be relegated to a defensive role. The Black knight retains the option of going to d7 leaving the c-pawn mobile, but it is not without reason that 2\...Nc6 is much more common than 2\...d6. {{-}} ### Danish Gambit 1.e4 e5 2.d4 exd4 3.c3 dxc3 4.Bc4 cxb2 5.Bxb2 This gambit gives White quick development and control of the center at the cost of two pawns initially. However, current opinion reports that to properly fend off the attacking waves, at least one and sometimes both pawns must be returned. This involves the liberating pawn push \...d5 by Black. Even so, inventive attacking players can still use the resulting open lines to play a complex game. {{-}} ### Sicilian Defence 1.e4 c5 Play can continue 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 (2\...d6 and 2\...e6 are also common, and usually also met by 3.d4) The Sicilian is the most common and best-scoring response to 1.e4, as it balances the white advantage with flank play. It discourages White from occupying the centre with 2.d4. After 2\...cxd4 White must either take the pawn back with the queen (and move it again after 3.Qxd4 Nc6) or sacrifice the pawn, usually with 3.c3. One problem with the Sicilian is that there is a vast amount of theory written on it, and in a sharp opening like this, you can wind up in trouble if you don\'t know it. {{-}} ### French Defence 1.e4 e6 2.d4 d5 White has three essential continuations: 3.Nc3 \"Winawer Variation\" 3.Nd2 \"Tarrasch Variation\" 3.e5 \"Advance Variation\". A fourth alternative, the \"Exchange Variation\" is 3. exd5, but this actually frees Black\'s game from all of the traditional cramping problems of the French Defence. It is mainly used by White players who forgo all attempts at a theoretical battle, hoping to play on \"general principles\". The French Defence is considered one of the strongest black responses to the White opening move 1.e4. Among world class grandmasters, it currently trails the Sicilian 1. e4 c5 and the symmetrical 1.e4 e5 in popularity. {{-}} ### Pirc Defence 1.e4 d6, usually followed by 2.d4 Nf6 3.Nc3 g6 {{-}} This opening bears considerable similarities to another one called the King\'s Indian, which begins 1.(e4 d6) d4 Nf6 2. c4 g6 3. Nc3 Bg7. However, subtle but long range strategic differences exist between the two. In the Pirc, White\'s c-file pawn is still at home, and not committed to the c4 square. This means that overall, White has better control of the d4 square. The pawn move c2-c4 has been replaced by a developing piece move N-c3, and this \"faster\" development tends to encourage White towards central or kingside attacks compared with the queenside play classically associated with the King\'s Indian defence. ### Modern Defence 1.e4 g6, usually followed by 2.d4 Bg7 {{-}} This move order is often used to \"back into\" a Pirc defence, while avoiding specific move order issues. However, an entirely different range of strategy is possible based upon \...c6 and \...d5. ### Alekhine\'s Defence 1.e4 Nf6, usually followed by 2.e5 Nd5 3.d4 d6 This looks like a rather alarming opening for Black to play. Black lets White chase the knight around the board and use that time to build up the pawn centre. Black\'s plan is to show that White has expanded too quickly, and will find the pawn centre vulnerable. The disadvantage to this opening is that if White succeeds in maintaining it, White will have a serious and suffocating advantage in space. {{-}} ### Scandinavian Defence 1.e4 d5, usually followed by 2.exd5 Qxd5 3.Nc3 Qa5 Playing d7-d5 is the main idea behind most of the semi-open games for black. Here it is played immediately for the price of an extra move with the queen after 3.Nc3. Long disparaged as the epitome of weak play \"because moving the queen early wastes time\", it was resurrected in the 1990s with a pawn move c7-c6, allowing the queen to retreat from a5 to c7 when necessary. Now it is considered an attempt to reduce White\'s central pressure, and is popular among club players because White suddenly has to demonstrate some sophistication. {{-}} 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 Nf6 5.Nf3 Bg4 6.h3 - possible continuation\... This is a general continuation of the Scandinavian Defense. White developing its pieces towards the center by 4.d4 and 5.Nf3 placing the Knight on the natural f3 square. Meantime black develops also in a simple way 4\...Nf6 and 5\...Bg4 creating a pin for the white Knight. There is another pin for c3 Knight - created by the d4 pawn push. Now white has to eliminate the pins - in order to make the Knights free to move. White can do it by 6.h3 move or 6.Be2 - simple relieve for the Bishop pin. After 6.h3 black Bishop can retreat by 6\...Bh5 - maintaining the pin or can capture the white Knight 6\... Bxf3. {{-}} 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qa5 4.d4 Nf6 5.Nf3 Bg4 6.Be2 ?! - thematic continuation\...not the best one\... Most of the club players - or \"players in the parks\" or casual internet players without any deep opening knowledge are taking this 6.Be2?! move as a smooth continuation to relieve from the Bishop pin. The normal development of the pieces continues 6\...Nc6 7.0-0 0-0-0 8.Be3 \... {{-}} ## Queen\'s Pawn Openings (closed and semi-closed games) ### Queen\'s Gambit 1.d4 d5 2. c4 {{-}} 2\...e6 3.Nc3 Nf6 4.Bg5 Be7 leads to Queen\'s Gambit Declined 1 variations. A special characteristic among the declined games has the Tarrasch-Defence 3\... c5, mostly followed by 4.Nf3 Nc6 5.cxd5 exd5. {{-}} 2\...c6 (usually followed by 3.Nf3 Nf6 4.Nc3 dxc4) leads to the \"Slav Defence\". {{-}} This is one of the opening \"families\" with interchangeable moves. It is quite possible to play both \...e6 and \...c6 (known as the Semi-Slav), and there are large numbers of interchangeable points called transpositions. 2\...dxc4 is the \"Queen\'s Gambit Accepted\". {{-}} Black has gained a pawn but Black cannot keep it. If White wants it back White can play e2-e3 at some point, threatening the pawn with the bishop and if Black tries to defend it with \...b5 Black will find the queenside severely weakened (and the pawn should fall anyway). Nonetheless, this is playable for Black as well, instead of trying to keep the pawn, it is best to develop quickly and strike back at the White centre. ### King\'s Indian Defence 1.d4 Nf6 2. c4 g6 {{-}} 3.Nc3 Bg7 4. e4 d6 {{-}} Popularised after World War II, the King\'s Indian Defence involves opposite sides strategies in a race between Black\'s mating attack vs. White\'s methodical attempts to unravel Black\'s Queenside. At World Class level, there is some concern that Black\'s concept is very committal, leading Former Champion Garry Kasparov to discontinue his use of the opening shortly before he retired from the game. At any level below that, it is still very popular due to the deep developmental work by Fischer and Kasparov. ### Grünfeld Defence 1.d4 Nf6 2.c4 g6 {{-}} 3.Nc3 d5 {{-}} Looks a bit like a cross between the Queen\'s Gambit and the King\'s Indian Defence, but this opening is played differently from both of them. Black gives White an early opportunity to grab control of the centre with 4.cxd5 Nxd5 5.e4. Black will need to launch a counterattack against that centre, perhaps with \...c5 to stop White from getting the upper hand. If Black succeeds, the White centre may indeed be very vulnerable, if Blacks fails, the centre will be very dominating. ### Nimzo-Indian Defence 1.d4 Nf6 2.c4 e6 {{-}} 3.Nc3 Bb4 {{-}} After 3.Nc3, White threatens to take control over the centre by playing 4.e4. The Nimzo-Indian, named after the hypermodern player Aron Nimzowitch, is one of the two main ways of preventing this (the other way is the direct 3\...d5 which leads to the Queen\'s Gambit Declined). Black puts a bishop where it pins the White knight, and often intends to trade it off, surrendering the bishop pair but inflicting White with doubled pawns if needed to recapture with the b-pawn. White can avoid these doubled pawns by playing the queen to c2, but this costs time. On the other hand, Black has not staked out a big claim of the centre yet, and White can get a real space advantage if Black is careless. ### Queen\'s Indian Defence 1.d4 Nf6 2.c4 e6 {{-}} 3.Nf3 b6 {{-}} Strategically, this opening is similar to the Nimzo-Indian. White has played 3.Nf3 rather than 3.Nc3 so he is not threatening to grab the center with 4.e4 just yet. Playing the Nimzo-like 3\...Bb4+ anyway is possible (and called the Bogo-Indian) and tends to lead to rather quiet play. More usual is 3\...b6 which opens up for the bishop to go to b7 where it will continue the clamp-down on the e4-square, or to a6 where it will put pressure on White\'s pawn on c4. ### Modern Benoni 1.d4 Nf6 2.c4 c5 {{-}} 3.d5 e6 {{-}} ### Benko Gambit 1.d4 Nf6 2.c4 c5 {{-}} 3.d5 b5 {{-}} ## Other openings ### English Opening 1.c4 {{-}} Black\'s most common responses are: 1\...e5, a reversed Sicilian Defence {{-}} 1\...c5 {{-}} 1\...Nf6 {{-}} 1\...e6 (preparing 2\...d5) {{-}} and 1\...c6 (preparing 2\...d5) {{-}} ### Réti Opening 1.Nf3 d5 2.c4 {{-}} ### Benko Opening {{-}} This opening threatens to fianchetto the bishop on f1 to g2, threatening a rook capture, or h3, threatening a bishop exchange, either of which would also threaten a Black pawn center. However, this opening is rather passive and is relatively easy to parry. ### King\'s Indian Attack 1.Nf3 d5 2.g3 {{-}} ### Barnes Opening This can end almost as quickly as it begins, with an extremely fast checkmate by Black (called fool\'s mate.) {{-}} The Barnes Opening goes like this: 1.f3 e5. {{-}} It can be continued as the Fool\'s Mate: 2.g4?? Qh4#. Fortunately for White, the fool\'s mate is extremely rare, even among novices, because the Barnes Opening is passive and has no advantage over 1.f4, and because it is very easy for even a novice to see that the continuation of the Barnes Opening gives Black an immediate mate opportunity. it:Scacchi/Aperture di base fi:Shakkiaapinen/Avausteorian alkeet
# Chess/Sample chess game \_\_NOTOC\_\_ This is a sample game of chess, recorded in standard algebraic chess notation and accompanied by commentary. White has the first move and therefore a significant initiative. White wins 10% more often than Black simply on the power of that initiative. It is important not to squander the opening advantage with a move that does nothing. ## Moves 1-5 ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 1. e4 White chooses an excellent move, common among beginners and experts alike. The move has several advantages: 1. It stakes out territory in the center. A player who controls the center with pawns will probably be able to find good squares for their pieces. 2. It opens a diagonal for the king\'s bishop to move out and attack, which also facilitates kingside castling. 3. It opens a diagonal for the queen to move out and attack. This move follows the two most important principles of an opening move: 1. develop a piece, or facilitate the development of a piece, and 2. control the center. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 1\... e5 This move for Black is good for the same reasons listed above. Note that the two e-file pawns are not threatening to capture each other, because pawns capture diagonally. Instead, they merely block each other until something breaks the logjam. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 2. Nf3 White makes another fine move. White is mobilizing forces by bringing a knight forward into an attacking position. Because the white knight is attacking Black\'s e-pawn, White is maintaining the initiative by forcing Black to react. So now, Black must choose a move that defends the pawn, or else he might lose it. The initiative may appear to offer only a slight edge, but at the hands of a master, it can be deadly. White could have moved out the queen instead, but that would be dangerous. The queen is generally too valuable to trade for any other piece except the enemy queen (however, it can be traded for multiple enemy pieces of equivalent total value, such as two bishops and three pawns; two bishops and a knight; or a rook, a bishop, and a pawn, for instance), so it can\'t do much by itself unless the opponent carelessly leaves pieces unprotected. Thus, your opponent can keep attacking your queen with different pieces. And while you are simply moving your queen around, your opponent will be able to keep developing their pieces. It is better to wait until there are other pieces in the fray which can serve as shock troops for her. White also could have moved out the kingside bishop. That would not be a bad idea, but it isn\'t clear yet whether the bishop wants to be at c4, b5, or possibly even behind the pawns. The knight, on the other hand, usually goes to f3 anyway, because the other squares it could move to are inferior: on h3, it would not attack the center, and on e2, it would be temporarily in the way. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 2\... f6? Black makes a worthless move, entering the infamous Damiano Defense. Black needed to defend his pawn with either 2\...Nc6 (main line) or 2\...d6 (Philidor Defense), or counterattack White\'s pawn with 2\...Nf6 (Petrov\'s Defense). Either of the knight moves would have maintained the balance of the game by contesting the center. If Black felt brave, he could also venture into the murky waters of 2\...f5 (Latvian Gambit) or 2\...d5 (Elephant Gambit). The move 2\...f6 appears to defend the threatened e-pawn, but this is an illusion, as the game shall demonstrate. Black has weakened the kingside, allowing attacks on the f7-square, which is protected by nothing other than the king itself. This weakening is called \"opening the door,\" and White must take advantage of this. Black has failed to follow the principles here and has received no compensation. He has affected the center, but the move 2\...d6 would have done the same and gained some control on the queenside. Also, he has not developed a piece, nor has he facilitated the development of a piece. 2\...Nc6 would have developed and gained control in the center, and 2\...d6 would have gained some control on the c8--h3 diagonal and facilitated the development of the light-squared bishop. Black has also weakened his kingside. Any pawn moves in front of a castled king can be useful weaknesses for the opponent. Since pawns cannot go backwards, you should be very cautious of any pawn moves on the side you wish to castle on (usually the kingside). The moves 2\...f5 and 2\...d5 seem to not adhere to the principles. Why have these moves been brought up? The fact is that the best moves in a position will sometimes break principles, but they will offer compensation for whatever gains are lost by not following the principle. So, in a sense, the principles tell us what questions to ask ourselves when making a move, such as, \"Should I develop now?\" So it is important to understand the principles in order to decide if you are getting enough compensation. It is not always good to blindly do whatever the principles dictate. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 3. Nxe5 White attacks immediately, sacrificing the white knight for a pawn, although White would generally need three pawns for the knight to have material equality. Before making this sacrifice, White has to calculate to make sure he is going to gain something that compensates for the lost material. In this case, as the following moves show, White knows that he will gain an attack on the enemy king, forcing Black to either surrender more material or allow checkmate. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 3\... fxe5? Black makes the only move consistent with 2\...f6, but it is not best. The best try for an equal game was 3\...Qe7, skewering White\'s knight and pawn and putting pressure on White\'s king. That is to say, the queen would indirectly be attacking everything in the e-file. After the knight moved away, the queen could take on e4 with check, regaining the pawn. White would, however, have a large advantage because of his lead in development and Black\'s weakened kingside pawn structure, e.g. 4.Nf3 Qxe4+ 5.Be2, likely followed by 0-0 and Nc3, attacking the queen. Retaking the knight now merely invites White\'s queen to jump into the fray with check. The fact that Black cannot afford to take the knight shows that 2\...f6 did not really protect the pawn at all. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 4. Qh5+ The game\'s first check! There are three legal ways to respond to check: 1. Capture the piece giving check. Here, this is impossible, as Black has nothing which can move to h5. 2. Interpose a piece between the king and the piece giving check. Black could play 4\...g6, but that would lose a rook to 5.Qxe5+ and 6.Qxh8. 3. Move the king out of check. Moving the king to f7 leaves it in check and is thus illegal, so e7 is the only square to move out of check. Note that White has forked the king on e8 and the pawn on e5. There is no time for Black to protect both, so no matter what Black does to get out of check, White\'s queen can take on e5. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 4\... Ke7 This move leaves Black in a dangerous position because the black king is so exposed. Furthermore, the black rooks, bishops, and queen still have no way to get out. The black position is no more developed than it was at the start of the game. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 5. Qxe5+ Another check. Black now has only one legal move: Black can\'t interpose anything between the king and queen, and he can\'t take the queen, so the black king must be moved out of check. There is only one square next to Black\'s king which White\'s queen is not threatening. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 5\... Kf7 Black moves the king; it\'s the only available move to play. White\'s queen is a dangerous attacker. However, because it is too valuable to trade for anything, it can only take undefended pieces. Everything in Black\'s camp that the white queen could target is defended by something, so the queen has done all it can do by itself. It is time to bring in reinforcements. ## Moves 6-10 ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 6. Bc4+ This is an excellent move to keep the pressure on Black because it develops a piece and gives check while preventing Black from consolidating. If White had played less energetically with 6.Nc3, the advantage would have evaporated instantly. Black could answer with 6\...Nf6, bringing a piece to the defense. If Black gets his king to safety, Black might actually be winning: White has only two pawns for the sacrificed knight, giving him a material disadvantage. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 6\.... d5! Black makes an excellent defensive move. Never forget that moving the king isn\'t the only way to get out of check! Admittedly, Black\'s d-pawn is a dead duck. It is attacked by White\'s bishop, queen, and pawn, three times altogether, while it is defended only once, by Black\'s queen. The sacrifice is worthwhile, though, to open up lines for the queen and bishop so they can help with the defense. Now, if White fails to find the best continuation, Black has some chance to counterattack. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 7. Bxd5+ White gives check yet again, which prevents Black from doing anything constructive. Let\'s review the three ways to get out of check: 1. Capture the piece giving check. Black could play 7\...Qxd5. However, White would simply take the queen with 8.Qxd5+. With such a huge material disadvantage and an exposed king, Black could resign without feeling like a quitter. 2. Interpose a piece. Black could play 7\...Be6. However, that would be inadvisable because the bishop would be defended only once (by Black\'s king) and attacked twice (by White\'s queen and bishop). In fact, White could end the game at once with 8.Qxe6#. 3. Move the king. Alas, the only square which is not under attack by White is g6, even further into the open. It beats the alternatives, though. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 7\... Kg6 Now White must think of a way to continue the attack. White would like to play 8.Qf5+, driving Black\'s king to h6 where it can be cornered and checkmated, but Black\'s c8-bishop is guarding the square f5. If Black hadn\'t interposed with 6\...d5, Black would now be subject to a forced checkmate. As it stands, White has to be more creative to keep the initiative. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 8. h4 Again, White finds a strong continuation. White is threatening to force the Black king to h6 after all with h5+. Also, the pawn protects the g5 square, which is important in some mating combinations. Finally, there is some chance the rook will be able to join the attack down the h-file. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 8\... h5 Black plays a tenacious defense in a precarious situation. White\'s pawn is blocked from further advances, and the king has a new escape square on h7. Black\'s position is still precarious, but there is no immediate way for White to force checkmate. Now let us take a step deeper into chess reasoning. White knows Black is on the run for the moment, but if Black has a chance to regroup, the game is far from over. Three pawns for the sacrificed knight is roughly material equality. If White brings additional forces forward with 9.Nc3 or 9.d4, the obvious developing moves, Black will harass White\'s queen with 9\...Bd6. That would force White to lose time protecting the queen. Black would gain enough time to get the black pieces out and get the black king to safety. White desperately wants a quick kill but can\'t see how to get it. White is annoyed that Black\'s bishop on c8 prevents White from playing 9.Qf5+ and administering the coup de grace. Therefore, White asks the question, \"What if Black\'s bishop were not on c8? If only that annoyance were removed, I could do great things.\" ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 9. Bxb7!! White finds a forceful continuation that puts Black in dire straits. Black\'s best bet now is to ignore White\'s bishop and harass White\'s queen with 9\...Bd6, but then White calmly plays 10.Qa5, maintaining the threat on f5 and forcing Black to lose material. One possible line of play is 9\...Bd6 10.Qa5 Nc6 11.Bxc6 Rb8. The checkmate has been avoided, but now White has a large material advantage of four extra pawns, and he can win slowly and surely with patient developing moves like 12.Nc3. (Note that after 9\...Bd6 10.Qa5, Black cannot play 10\...Bxb7 because of 11.Qf5+, with the same play as in the main variation below.) As it happens, Black does not understand the danger. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 9\... Bxb7? Black grabs the bishop to gain a material advantage (bishop plus knight versus four pawns). This is Black\'s critical error, allowing White\'s attack to break through. From here on, White has a forced mate. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 10. Qf5+ The crushing move can be unleashed at last. Black has only one legal reply. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 10\... Kh6 This is the only move to get out of check: the white queen cannot be taken, and any other moves for the king would leave it under attack. ## Moves 11-14 ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 11. d4+ White continues the attack with a special kind of check, a discovered check. White moves a pawn, but it isn\'t the pawn which gives check. It is White\'s bishop, attacking from its home square, which delivers the blow. Note that Black\'s king has no legal moves, and White\'s bishop is safe from capture, so interposition is the only option. But because it is an option, this is not yet checkmate. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 11\... g5 At this point, White has an easy win with 12.Bxg5+ Kg7 13.Bxd8. The material advantage of a queen and five pawns for a bishop and a knight is overwhelming. However, weak players have been known to play on in completely hopeless positions rather than resign. In order to forestall a long, boring mop-up operation, White looks for a direct kill. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 12. Qf7! Truly a masterful move! White doesn\'t even call check, but mate is now inevitable. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 12\... Qe7 Nothing can save Black now short of White forgetting the plan, but there is some logic to Black\'s move. Where can White\'s queen go? Any of Black\'s pieces that it could take are protected. If White trades queens, then the attack is over, and Black is winning. Finally, if White\'s queen simply retreats, Black will strike back with check: 13\...Qxe4+! However, White must have foreseen this possibility when playing his last move. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 13. hxg5+ This checks Black\'s king and destroys Black\'s pawn cover. Black can\'t get out of this check by interposition or by moving the king away. All retreat is cut off by White\'s well-placed queen. The only option is to capture the checking piece. ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 13\... Qxg5 ```{=html} <div class="thumb tright"> ``` ```{=html} </div> ``` ##### 14. Rxh5# Checkmate. Black can\'t interpose anything, because the rook is giving check from an adjacent square. Black\'s king can\'t move away, because White\'s queen covers all retreat squares. Black\'s king can\'t capture the rook, because then it would be in check from White\'s queen. Finally, Black\'s queen can\'t capture White\'s rook because it is pinned. If Black\'s queen moved away, White\'s bishop on c1 would be giving check to Black\'s king. Notice that, although material considerations are very important in chess thinking, one doesn\'t win by having the most pieces. One wins by delivering checkmate. White has been behind in material almost the entire game, including in the final position, but comes away with the victory nonetheless. ## Move list in Portable Game Notation Here is the game in Portable Game Notation (PGN) format. Most computer chess programs have an easy way to import games in this format. In the best case you can just copy the following code, start your chess program and paste the code to it: `[Event ""]`\ `[Site ""]`\ `[Date "????.??.??"]`\ `[Round ""]`\ `[White "White"]`\ `[Black "Black"]`\ `[TimeControl "-"]`\ `[Result "1-0"]`\ \ `1.e4 e5 2.Nf3 f6 3.Nxe5 fxe5 4.Qh5+ Ke7 5.Qxe5+ Kf7 6.Bc4+ d5 7.Bxd5+ `\ `Kg6 8.h4 h5 9.Bxb7 Bxb7 10.Qf5+ Kh6 11.d4+ g5 12.Qf7 Qe7 13.hxg5+ Qxg5 `\ `14.Rxh5# 1-0` ms:Catur/Contoh permainan
# Chess/The Endgame The Endgame is the last stage of chess, and arguably the most important. Even if you succeed in the opening and middle stages of the game, not knowing the skills to turn the resulting endgame into a checkmate can cost you many wins, turning many otherwise easily won positions into draws or even losses. For this reason, we recommend devoting a good portion of your study to endgames. If you\'re still beginning your chess studies, the Basic Checkmates section should be enough to cover the simplest scenarios appropriate for your level. More complex situations are covered in the second part of this manual, suitable for those who already have a decent grasp of the easy checkmates. ## Basic Checkmates These include positions that have no pawns. When one side is ahead in material and has pawns, the easiest winning plan is typically to queen one or more pawns and use them to checkmate. The situations where one has a king and queen, king and two rooks, or king and rook versus a lone king occur very often and it is essential to know how checkmate is achieved in such cases. The other cases, with minor pieces (bishops and knights) are more rare and more difficult to perform, but nonetheless are covered here for completeness. - King and Queen vs. King - King and Two Major Pieces vs. King - King and Rook vs. King - Minor Pieces - Pawn Endings ## More Advanced Endgames These are situations that occur less commonly in games, but are still very important. Most intermediate to advanced players are expected to have at least a basic understanding of how these endings work. - Endings with Multiple Major Pieces - Rook and Minor Piece Endings - Rook and Pawn Endings - Endings with 3+ Minor Pieces - Other Endgames ------------------------------------------------------------------------ - Endgame Studies and Puzzles ## External links - Interactive King + Queen vs King Checkmate - Interactive King + Rook vs King Checkmate - View endgames involving the King+Knight+Pawn vs. King+Knight+Pawn - View endgames involving the King+Pawn vs. King+Pawn - View endgames involving the King+Queen+Pawn vs. King+Queen+Pawn - View endgames involving the King+Rook+Pawn vs. King+Rook+Pawn - View endgames involving the King+Bishop+Pawn vs. King+Bishop+Pawn \_\_NOTOC\_\_ it:Scacchi/Finali ro:Şah/Finalul
# Chess/Variants !De ludo scachorum, 1493 Just as chess has changed over the centuries that it has been played, there are people who try to add new features or ideas to chess even now. Sometimes this is just a minor rule change to make things interesting, but sometimes there are whole new ideas that are proposed that will modify chess so substantially that it essentially is a whole new game to be played. The following are some chess variants to be considered if you want to experiment with alternative ideas for playing chess: Many other chess variants can be found on Wikipedia. - /Random Opening Chess/ - Arimaa - /Bug House/ and /Crazy House/ - /Crazy House/ (see /Bug House/) - /Chinese Chess/ or Xiangqi - Shogi or Japanese Chess ## Fairy chess It is possible to invent a piece that moves according to any defined set of rules. In fairy chess, pieces are typically divided into three categories: leapers, riders, and hoppers. A leaper moves directly from one square to another, regardless of the position of any other pieces on the board. In ordinary chess, the knight is a (2,1) leaper: it moves one square horizontally and two squares vertically, or vice versa. The king is a hybrid (1,0) and (1,1) leaper: it moves to any adjacent square. Fairy chess has pieces called camels and zebras: these are long-range leapers like knights, except that they leap (3,1) and (3,2) respectively. Note that a (3,1) leaper, like a bishop, always stays on squares of the same color, but a (3,2) leaper, like a knight, always moves to a square of the opposite color. A rider is a leaper that can make multiple leaps in the same direction on the same move. In ordinary chess, the bishop is a (1,1) rider: it can move to any square diagonally, no matter how far away it is, as long as there is no other piece blocking the diagonal line. Similary, the rook is a (1,0) rider. The queen is a hybrid (1,1) and (1,0) rider. A special fairy chess rider is the nightrider or knightrider. This is a knight that can make consecutive knight-hops in the same direction on the same move. A hopper is a piece that moves in a line while hopping over another piece. There are no hoppers in ordinary chess, but the capture rule in checkers is a kind of hop: the capturing piece jumps over the opponent\'s piece, which is then removed from the board. Also, the cannon in Xiangqi is a hopper. In fairy chess, a hopper may or may not be restricted to jumping over pieces of one color or the other; and the piece that is jumped over may either stay on the board or be removed, depending on the rules for that particular hopper. The prototypical fairy chess hopper is the grasshopper. It moves in any direction, like a queen, but it can move only by hopping over another piece, and it lands one square beyond that piece. The piece that is jumped over is not removed from the board; however, a locust is a special type of grasshopper, which captures an enemy piece over which it jumps. T. R. Dawson, one of the most prolific chess composers of all time, defined the concepts of fairy chess in the 1930s, and produced many problems using invented pieces such as the nightrider and grasshopper. Fairy chess has become a popular domain for chess composing and solving, especially because it offers a level of creativity that is sometimes hard to find in the more thoroughly developed areas of traditional chess composition.
# Chess/Tournaments If you want to play chess in serious competition, beyond the casual play, you may want to play in tournaments. The strength of the tournament players can vary greatly from tournament to tournament, as well as within the tournament. ## Types of tournament Common tournament forms include - Master tournaments are usually closed events where very strong players are invited to play against each other. As a new player, you will probably not wind up in such tournaments for some time (if at all). However, there are frequently side events to a master tournament, open to other players. - Open tournaments are generally open to any player who has the required memberships, and who want to play. There may be some very strong masters in such tournaments as well, but the list of players usually will include a majority of amateur players. Open tournaments, in particular larger events, may be sectioned, where the lower sections are limited to players with a chess rating below some threshold. How players without ratings are handled may vary from event to event; if in doubt, contact the organizer. - Scholastic events are tournaments set up for children in school age. They tend to feature faster time controls than the adult events. Children in school age are usually more than welcome to enter adult tournaments, although the youngest children, or those with little or no tournament experience may find themselves outclassed in such events. Some tournaments may be arranged over one day with several fast games being played (or a small number of rounds). Some are arranged over the course of a weekend. Larger international tournaments are frequently a week long, with one round a day. Club tournaments may last over several months, with an evening round each week. ### Tournament formats The most common tournament formats are round robins and Swiss systems. The round-robin is an all-play-all event, usually in small sections. You will during the course of a round-robin meet everyone else in the section. Perhaps even more common is the Swiss system, where you in each round meet a player who has a score similar to your score. So if you have lost your first game, you will most likely meet another player who lost the first game as well for the next round. You are never eliminated from a Swiss system event, if there are an odd number of players the worst that can happen is that you receive a \"bye\", which means you get a free point (as if you won a game) instead of a game for that particular round. The bye is generally awarded to a player in the lowest score group, but a player can only receive one of them. In some events the organizer may arrange for an extra game for the player who got a bye. ## Where to find tournaments Most countries have a national chess federation or association, and their websites usually have notes about tournaments. For the United States tournament announcements may be found on the USCF website\'s tournament search engine, but it does not list all events, smaller events are often not listed. Websites of the state affiliates may include more local events). For other countries you can find links to the national chess federations here. ## Requirements for entering a tournament ### Rules You should be sure you know how the pieces move, and how a game ends. In particular, you need to know the rules of en passant, castling, pawn promotion and the three-time repetition of position rule. You should know how the chess clock is used. In all tournaments you have to complete your moves within a time limit, which varies from tournament to tournament. Furthermore, you should know how to record the game using algebraic chess notation. Most tournaments with reasonably long time limits require players to keep score of the game. This is not an absolute requirement, players who are unable to keep score for various reasons, be they religious or due to an inability to write, may be exempted. Additionally, players who are in time trouble (with less than five minutes on their clocks) can be temporarily excused from writing moves to conserve time, although they are encouraged to update their scoresheets with the opponent\'s score if/when a time control is reached. In tournament play, the touch-move rule is strictly enforced. If you touch a piece of your own you must move it (if you have a legal move), when you\'ve released the piece after a move it stays. If you touch your opponents piece you must capture it, provided that you have a legal capture. If you merely wish to adjust a piece which is standing askew on the square, you may do so if you warn your opponent (\"I adjust\" is fine, but the French \"J\'adoube\" is also popular) before you touch the piece. Remember that tournaments can, and should, be fun, but they are pretty formal events. Distracting or disturbing your opponent is prohibited. In addition, you should refrain from talking in the tournament hall as much as possible. If you have to communicate something to someone, do it as quietly and discreetly as possible. If, after finishing a game, you and your opponent want to go over it, go to a different room to analyse instead of remaining in the playing hall pushing pieces around - it distracts nearby players. Remember to turn mobile phones off before the game starts! If a mobile phone rings during the game, a penalty is usually assessed by the arbiter, depending on the tournament. In most USCF tournaments, for a first offence ten minutes is removed from the offending player\'s clock, and for a second offence the game is forfeited as a loss. There is nothing more embarrassing than the faux pas of a loud ringtone going off in an otherwise dead silent playing hall and half a dozen people from nearby boards glaring at you. The FIDE laws which most other countries play by are even more strict: mobile phones are prohibited altogether, and if a player is found to be in possession of a mobile phone, then that player loses. Organizers may announce a more lenient policy, but unless you are informed otherwise, assume that the strict \"no mobile phones\" rule applies. From 2009, the general rule at serious, professional tournaments about arriving late to the board is a zero tolerance policy. If you are not present at the board when the round starts, you forfeit the game. This has sometimes been enforced in a draconian fashion, one player in the Chinese Championship who was standing near the board waiting for the game to start was forfeited when the round started because she wasn\'t sitting at the board 1. A tournament may announce a more lenient rule where a latecomer is forfeited only if a certain time elapses (one hour was the limit before the rule change in 2009), and some federations have announced that one hour will remain the default standard for all tournaments in their country (such as the USCF). However, even if arriving late does not forfeit the game automatically, your clock will be started on time, so unless you are willing to waste the time you have for thinking, don\'t be late for your game. Full laws can be read here. (Note that the United States have slightly different tournament regulations.) ### Membership In most events, it is required that you are a member of the country\'s chess association. In the United States, this means that you must be a member of the United States Chess Federation and so on. Some events may require further memberships, club championships may require membership in that club for instance. For many events in Europe, membership in any national chess federation associated with FIDE may be sufficient (this allows foreign players to play without purchasing new memberships all the time.) The organizer can nearly always arrange a membership for you, so don\'t feel like you cannot go to a tournament just because you aren\'t a member yet. ### Equipment In most tournaments in the United States, players are expected to provide boards, sets and clocks. Pieces should be of normal Staunton design, with a king about 3-and-a-half inches to 4 inches tall, and the board should have squares of around 2 to 2-and-a-half inches. A cheap roll-up board with normal plastic pieces is quite sufficient. Clocks can be purchased in many places, and the prices can vary. Shop around. Some sets include an extra pair of queens, so that one can handle the situation where a player gets two queens due to pawn promotion. While helpful, this is not essential. In tournaments, multiple queens should be handled by fetching an additional queen, and not by placing an overturned rook in place of a queen. The situation is fairly rare in practice however, and when it does happen, you can usually borrow a queen from someone else. In Europe equipment is usually provided, though some events may have a shortage of clocks, and ask players to provide that. Bring a pen to write with so that you can keep score. ## General advice for play - Remember that tournament play is a learning experience. After the game try to go through the game with your opponent so that you can learn from mistakes made. Do this especially when you have lost, because here you must have done something wrong where your opponent did something right, and you should try to avoid losing the same way again. - Inexperienced players sometimes get distracted by the clock, and start playing too fast. If you have two hours available to make 40 moves, but have only used thirty minutes when the 40 moves are up, you have probably played too quickly and consequently not thought the position through well enough. - If you get a winning position, be careful! Your opponent will in all likelihood be looking for ways in which you can go wrong, letting him escape with a draw or turn the tables and win. ## Withdrawing Try to complete the tournament, even if you have started badly. The opposition will tend to get easier, and learning how to bounce back after setbacks is important. If you must withdraw, you must tell the organizer that you are going to do so. Otherwise the player you would have met will be deprived of a game. (That player gets awarded a full-point as if the game were won, but the entry fee was probably paid for an opportunity to play chess, not to sit at a table with nobody to play with!) In some cases, a player dropping out without informing the organizer, may face a fine, and be excluded from that organizer\'s future events until the fine is paid. ## Ratings Tournament players are after a stipulated number of games assigned a rating, which is an estimate for the strength of that player. This goes up and down depending on the player\'s performance in rated events. The average rating of a tournament player is around 1400, the strongest grandmasters have ratings in the excess of 2700. As a rule of thumb, a player with a rating 200 points higher than the opponent should expect to score 75% against that opponent, and 90% against someone rated 400 points lower, but upsets are in practice more common than what the rating formulas predict. Understand that an average tournament player of 1400 is, compared to a casual player who only knows the rules, but with no tournament experience or study of the game, a very strong player indeed. A new player who enters a tournament may easily find the first rating to be below 1000, but as experience is gained this may rise! Remember, ratings are only estimates of playing strength based on past events. Ratings do not measure a person\'s ability to improve, they are not rewards in themselves, and they are definitely not measures of self-worth. In tournament play, ratings determine what sections you are eligible to play in, and which opponents you will meet in Swiss system events. ## Glossary of terms - Arbiter or tournament director is the authority which referees the event, makes pairings, and rulings. - Board 1, board 2, etc.. In Swiss system events boards are numbered. The players who currently have the best scores are seated at board no. 1, while those with the weakest scores are seated further down. - Class prize. A prize awarded to a player for finishing at the top of his or her rating class. A prize could be awarded for instance for \"first place among those rated below 1600\". - Entry fee. The amount a player is charged in order to be allowed to participate. - Flag. On analog chess clocks, the flag is a small device attached just left of the \"12\" on the clock face. As the minute hand approaches 12, it lifts the flag up so that it falls once the minute hand passes 12. This flag fall makes it possible to determine exactly when the time has expired. For example, if each player has 90 minutes, the clocks are initially set at 4:30, and the time has expired when the flag falls when the clock is at 6:00. (Technically, the flag also falls at 5:00, but this has no consequence.) Digital clocks usually have some indicator marking expiry, and the indicator when this is activated is also called a \"flag fall\". If the time control stipulates that a certain number of moves be made within a time limit, the last required move must be completed, and the clock stopped, before flag fall, otherwise that player has overstepped the time limit. - Forfeit loss/forfeit win. If a player fails to arrive at the board an hour after the announced starting time, then that player loses by forfeit, and the opponent receives a forfeit win. The game counts for tournament standings, but not rating. A person who loses by forfeit is typically removed from the tournament, unless an adequate excuse is provided. A player who has received a win by forfeit is ineligible for receiving a full-point bye in future rounds. - Full-point bye or walkover. If there is an odd number of players for a round, the arbiter will award a full-point bye to one player who does not play that particular round, but instead receives a point as if a game was won. - Half-point bye. In some tournaments, a player who is unable to play a particular round may elect to take a half-point bye. The player does not play that round but receives a half-point instead as if a game were drawn. Tournaments frequently regulate such byes, putting a cap on how many can be taken and/or requiring that a player commit to taking them before a certain deadline. - Increment. A small amount of time (the increment) which is added to a player\'s clock at every move. This avoids frantic time scrambles by ensuring that there will always be enough time to make a move. Some tournaments stipulate a time limit with an increment, others do not. Games played with an increment require a digital chess clock with this capability. - J\'adoube. French for \"I adjust\", and can be said by a player before touching a piece to adjust it rather than move it. - Sandbagging. A fraudulent scheme where a player deliberately lowers his rating so that he may play in a lower rated section sometime in the future in order to win cash prizes. Sandbagging is a form of cheating, and people caught may face stiff sanctions. - Sudden death. A time limit where one must make all remaining moves in a set amount of time. A time limit of \"40/90, SD/30\" means that each player must complete 40 moves in 90 minutes (that is the non-sudden death control), and then the remaining moves in 30 minutes (plus any time left over from the first time control), this second phase is the sudden death phase. - Swiss-system. An tournament format where players face other players with same or similar scores in each round. - Time control. The number of moves one must make within the time limit. For example if one must make 35 moves in 90 minutes, the time control is at 35 moves. - Time delay. A small amount of time (the delay) which passes before the clock starts deducting time from a player at every move. No time is deducted if a player moves before the delay is up. The idea is similar to that of an increment, but a player cannot build up a reservoir of time. Games played with a delay require a digital chess clock with this capability. In the United States, a five second time delay is standard, and clocks which have the delay capability are preferred over clocks which do not.
# Chess/Famous Games Throughout the history of chess there have been many famous games between the masters that many serious players are familiar. These games stand out because they contain unusual positions, feature brilliant sacrifices, or some other reason that sets them apart from average chess games. By studying and analysing these games, you can not only gain more appreciation for chess, but improve your strategy as well. This section is intended for readers with some knowledge of basic chess strategy. The games are provided with commentary to explain critical moves and point out strategy concepts. #### 19th Century: The Era of Gambits and Sacrifices - Anderssen vs. Kieseritzky, 1851: The Immortal Game - Anderssen vs. Dufresne, 1852: The Evergreen Game - Morphy vs. Duke Karl and Count Isouard, 1858: The Opera Game #### Early 20th Century: Steinitz, Lasker, and Capablanca - Alekhine vs. Nimzowitsch 1930 #### Later 20th Century: From Fischer to Kasparov - Byrne vs. Fischer, 1958: The Game of the Century - Caruana vs. Wojtkiewicz, 2002, Fabiano Caruana (10 years old) is the youngest player to defeat a GM [^1] #### Modern Era: Man and Machine - Deep Blue vs. Garry Kasparov, 1996: Game One - Kasparov vs. the World, 1999 ## References ```{=html} <references /> ``` \_\_NOTOC\_\_ [^1]:
# Chess/Puzzles Chess piece placement puzzles are puzzles where certain pieces have to be placed on the board and satisfy certain conditions. Chess checkmates are problems where White starts and mates in a clearly stated number of moves (or less). Chess endgames and middlegames are problems where the number of moves is indefinite, and White (or Black) has to either win or tie, as stated by the question. - Piece placement puzzles - Directmates - Endgame problems - Middlegame problems
# Chess/Computer Chess If you\'re interested in chess and wish to improve, you might want to consider installing a chess program onto your computer to help train you. Some programs are dedicated to certain areas of the game (such as endgame or opening study, or tactical exercises), while others allow you to input your games into a database and have the computer analyse them for errors and suggestions. Most regular tournament players usually have some sort of chess engine installed on their computer. These engines are programmed to find the best possible moves in any position given to them and determine who is ahead by means of algorithms. When plugged into an interface, you can either play directly against the engine or submit vary widely in quality and playing style. Some are commercial, others are freeware and available to download over the internet. Due to advances in technology in the 21st century, some of these engines have become so strong that even the best human players in the world have difficulty beating them, even on an average-speed home computer. A non-Master will probably never be able to beat - or even draw - a strong engine unassisted. In a sense, having a good chess program running over your games is almost like having a Grandmaster on hand to discuss your games with you. Engines are not all the same. Depending on how it\'s programmed, it may favour moves that are attacking and tactical, while others prefer solid, positional moves and don\'t take as many risks. Formerly, commercial engines were the strongest, but now some freeware engines are just as good or even better. Online If you don\'t want to install your own engine, you may play against one on a free online service. Be aware that these do not play at full strength and may not be allocated a lot of thinking time. In summary, they do not play at the highest level they can play at. - lichess.org features the powerful Stockfish engine in levels 1 through 8 (Glicko-2 ranges 1500 to 2361 \-- near Grandmaster), with 50 to 400 ms thinking time. You may set up positions using the Board Editor. You may analyse the games afterwards with Stockfish at nearly full strength, with 2 seconds of thinking time for each move. - GameKnot features a proprietary engine at levels ranging from \~1000 Elo rating to 2200+ (Grandmaster) Elo rating. Allows setting up a position from the Games DB. Does not offer a takeback option. Requires a Java Runtime. - The Shredder Chess website features the engine of the same name on easy, medium and hard levels. The hard level is particularly difficult for players of all skills. - Chess.com allows for users to play against other users, or against bots. Post-game review is also available for users to analyze their games. Interfaces Before you can use an engine, you first have to run it through an interface. There are many that can be used, the most common of which are listed: - \"Fritz\" interface - This is one of the most popular interfaces in use by professionals today. It generally comes prepackaged when you buy one of the commercial engines sold by ChessBase (Fritz, Shredder, Hiarcs, et al.). As such, it\'s considered commercial, although older versions of the interface may be released as freeware. (Be aware though, that there may be compatibility problems in this case.) - Arena = This is the most common freeware interface. It is compatible with Mac, Windows, and Linux. - Chessmaster - This interface comes prepackaged with the King chess engine. There are multiple training tools available as well, such as an openings book, tactics exercises, etc., so you don\'t have to purchase a separate program to do this. However, it may be harder to install independent chess engines to run underneath this interface. Engines Freeware: - Stockfish = Very strong open-source engine, consistently ranked as first or second strongest in the world.
# Chess/Optional homework These optional Worksheet problems will test your / your students\' ability to apply chess concepts. Try them and learn/teach! Each handout is designed to have a 20 minute time limit; feel free to use a timer, or adjust timing depending on the skill of your players. Each handout can be print using the \"Printable version\" button available on the left side of page. First, choose the groups so that no student on the same table has the same group (this allows to prevent cheating): - Group A - Group B - Group C - Group D ```{=html} <!-- --> ``` - /Solutions/
# Cognitive Psychology and Cognitive Neuroscience/Cognitive Psychology and the Brain Imagine the following situation: A young man, let's call him Knut, is sitting at his desk, reading some papers which he needs to complete a psychology assignment. In his right hand he holds a cup of coffee. With his left one he reaches for a bag of sweets without removing the focus of his eyes from the paper. Suddenly he stares up to the ceiling of his room and asks himself: "What is happening here?" Probably everybody has had experiences like the one described above. Even though at first sight there is nothing exciting happening in this everyday situation, a lot of what is going on here is highly interesting particularly for researchers and students in the field of Cognitive Psychology. They are involved in the study of lots of incredibly fascinating processes which we are not aware of in this situation. Roughly speaking, an analysis of Knut\'s situation by Cognitive Psychologists would look like this: Knut has a problem; he really needs to do his assignment. To solve this problem, he has to perform loads of cognition. The light reaching his eyes is transduced into electrical signals traveling through several stations to his visual cortex. Meanwhile, complex nets of neurons filter the information flow and compute contrast, colour, patterns, positions in space, motion of the objects in Knut\'s environment. Stains and lines on the screen become words; words get meaning; the meaning is put into context; analyzed on its relevance for Knut\'s problem and finally maybe stored in some part of his memory. At the same time an appetite for sweets is creeping from Knut\'s hypothalamus, a region in the brain responsible for controlling the needs of an organism. This appetite finally causes Knut to reach out for his sweets. Now, let us take a look into the past to see how Cognitive Psychologists developed its terminology and methods to interpret ourselves on the basis of brain, behaviour and theory. ## History of Cognitive Psychology Early thoughts claimed that knowledge was stored in the brain. ### Renaissance and Beyond Renaissance philosophers of the 17th century generally agreed with Nativists and even tried to show the structure and functions of the brain graphically. But also empiricist philosophers had very important ideas. According to David Hume, the internal representations of knowledge are formed obeying particular rules. These creations and transformations take effort and time. Actually, this is the basis of much current research in Cognitive Psychology. In the 19th Century Wilhelm Wundt and Franciscus Cornelis Donders made the corresponding experiments measuring the reaction time required for a response, of which further interpretation gave rise to Cognitive Psychology 55 years later. ### 20th Century and the Cognitive Revolution During the first half of the 20th Century, a radical turn in the investigation of cognition took place. Behaviourists like Burrhus Frederic Skinner claimed that such mental internal operations - such as attention, memory, and thinking -- are only hypothetical constructs that cannot be observed or proven. Therefore, Behaviorists asserted, mental constructs are not as important and relevant as the study and experimental analysis of behaviour (directly observable data) in response to some stimulus. According to Watson and Skinner, man could be objectively studied only in this way. The popularity of Behavioralist theory in the psychological world led investigation of mental events and processes to be abandoned for about 50 years. In the 1950s scientific interest returned again to attention, memory, images, language processing, thinking and consciousness. The "failure" of Behaviourism heralded a new period in the investigation of cognition, called Cognitive Revolution. This was characterized by a revival of already existing theories and the rise of new ideas such as various communication theories. These theories emerged mainly from the previously created information theory, giving rise to experiments in signal detection and attention in order to form a theoretical and practical understanding of communication. Modern linguists suggested new theories on language and grammar structure, which were correlated with cognitive processes. Chomsky's Generative Grammar and Universal Grammar theory, proposed language hierarchy, and his critique of Skinner's "Verbal Behaviour" are all milestones in the history of Cognitive Science. Theories of memory and models of its organization gave rise to models of other cognitive processes. Computer science, especially artificial intelligence, re-examined basic theories of problem solving and the processing and storage of memory, language processing and acquisition. For clarification: Further discussion on the \"behaviorist\" history. Although the above account reflects the most common version of the rise and fall of behaviorism, it is a misrepresentation. In order to better understand the founding of cognitive psychology it must be understood in an accurate historical context. Theoretical disagreements exist in every science. However, these disagreements should be based on an honest interpretation of the opposing view. There is a general tendency to draw a false equivalence between Skinner and Watson. It is true that Watson rejected the role that mental or conscious events played in the behavior of humans. In hindsight this was an error. However, if we examine the historical context of Watson\'s position we can better understand why he went to such extremes. He, like many young psychologists of the time, was growing frustrated with the lack of practical progress in psychological science. The focus on consciousness was yielding inconsistent, unreliable and conflicting data. Excited by the progress coming from Pavlov\'s work with elicited responses and looking to the natural sciences for inspiration, Watson rejected the study of observable mental events and also pushed psychology to study stimulus-response relations as a means to better understand human behavior. This new school of psychology, \"behaviorism\" became very popular. Skinner\'s school of thought, although inspired by Watson, takes a very different approach to the study of unobservable mental events. Skinner proposed that the distinction between \"mind\" and \"body\" brought with it irreconcilable philosophical baggage. He proposed that the events going on \"within the skin\", previously referred to as mental events, be called private events. This would bring the private experiences of thinking, reasoning, feeling and such, back into the scientific fold of psychology. However, Skinner proposed that these were things we are doing rather than events going on at a theorized mental place. For Skinner, the question was not of a mental world existing or not, it was whether or not we need to appeal to the existence of a mental world in order to explain the things going on inside our heads. Such as the natural sciences ask whether we need to assume the existence of a creator in order to account for phenomena in the natural world. For Skinner, it was an error for psychologists to point to these private events (mental) events as causes of behavior. Instead, he suggested that these too had to be explained through the study of how one evolves as a matter of experience. For example, we could say that a student studies because she \"expects\" to do better on an exam if she does. To \"expect\" might sound like an acceptable explanation for the behavior of studying, however, Skinner would ask why she \"expects\". The answer to this question would yield the true explanation of why the student is studying. To \"expect\" is to do something, to behave \"in our head\", and thus must also be explained. The cognitive psychologist Henry Roediger pointed out that many psychologists erroneously subscribe to the version of psychology presented in the first paragraph. He also pointed to the successful rebuttal against Chomsky\'s review of Verbal behavior. The evidence for the utility in Skinner\'s book can be seen in the abundance of actionable data it has generated, therapies unmatched by any modern linguistic account of language. Roediger reminded his readers that in fact, we all measure behavior, some simply choose to make more assumptions about its origins than others. He recalls how, even as a cognitive psychologist, he has been the focus of criticism for not making more assumptions about his data. The law of parsimony tells us that when choosing an explanation for a set of data about observable behavior (the data all psychologists collect), we must be careful not to make assumptions beyond those necessary to explain the data. This is where the main division lies between modern day behavior analysts and cognitive psychologists. It is not in the rejection of our private experiences, it is in how these experiences are studied. Behavior analysts study them in relation to our learning history and the brain correlates of that history. They use this information to design environments that change our private experience by changing our interaction with the world. After all, it is through our interaction with our relative world that our private experiences evolve. It is a far cry from the mechanical stimulus-response psychology of John Watson. Academic honesty requires that we make a good faith effort to understand what we wish to criticize. Henry Roediger pointed out that many psychologists understand a very stereotyped, erroneous version of psychology\'s history. In doing so they miss the many successful real world applications that Skinner\'s analysis has generated. Neuroinformatics, which is based on the natural structure of the human nervous system, tries to build neuronal structures by the idea of artificial neurons. In addition to that, Neuroinformatics is used as a field of evidence for psychological models, for example models for memory. The artificial neuron network "learns" words and behaves like "real" neurons in the brain. If the results of the artificial neuron network are quite similar to the results of real memory experiments, it would support the model. In this way psychological models can be "tested". Furthermore it would help to build artificial neuron networks, which posses similar skills like the human such as face recognition. If more about the ways humans process information was understood, it would be much simpler to build artificial structures, which have the same or similar abilities. The area of cognitive development investigation tried to describe how children develop their cognitive abilities from infancy to adolescence. The theories of knowledge representation were first strongly concerned with sensory inputs. Current scientists claim to have evidence that our internal representation of reality is not a one-to-one reproduction of the physical world. It is rather stored in some abstract or neurochemical code. Tolman, Bartlett, Norman and Rumelhart made some experiments on cognitive mapping. Here, the inner knowledge seemed not only to be related to sensory input, but also to be modified by some kind of knowledge network modeled by past experience. Newer methods, like Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) have given researchers the possibility to measure brain activity and possibly correlate it to mental states and processes. All these new approaches in the study of human cognition and psychology have defined the field of Cognitive Psychology, a very fascinating field which tries to answer what is quite possibly the most interesting question posed since the dawn of reason. There is still a lot to discover and to answer and to ask again, but first we want to make you more familiar with the concept of Cognitive Psychology. ## What is Cognitive Psychology? The easiest answer to this question is: "Cognitive Psychology is the study of thinking and the processes underlying mental events." Of course this creates the new problem of what a mental event actually is. There are many possible answers for this: Let us look at Knut again to give you some more examples and make the things clearer. He needs to focus on reading his paper. So all his attention is directed at the words and sentences which he perceives through his visual pathways. Other stimuli and information that enter his cognitive apparatus - maybe some street noise or the fly crawling along a window - are not that relevant in this moment and are therefore attended much less. Many higher cognitive abilities are also subject to investigation. Knut's situation could be explained as a classical example of problem solving: He needs to get from his present state -- an unfinished assignment -- to a goal state - a completed assignment - and has certain operators to achieve that goal. Both Knut's short and long term memory are active. He needs his short term memory to integrate what he is reading with the information from earlier passages of the paper. His long term memory helps him remember what he learned in the lectures he took and what he read in other books. And of course Knut's ability to comprehend language enables him to make sense of the letters printed on the paper and to relate the sentences in a proper way. This situation can be considered to reflect mental events like perception, comprehension and memory storage. Some scientists think that our emotions cannot be considered separate from cognition, so that hate, love, fear or joy are also sometimes looked at as part of our individual minds. Cognitive psychologists study questions like: How do we receive information about the outside world? How do we store it and process it? How do we solve problems? How is language represented? Cognitive Psychology is a field of psychology that learns and researches about mental processes, including perception, thinking, memory, and judgment. The mainstay of cognitive psychology is the idea where sensation and perception are both different issues. ## Relations to Neuroscience ### Cognitive Neuropsychology Of course it would be very convenient if we could understand the nature of cognition without the nature of the brain itself. But unfortunately it is very difficult if not impossible to build and prove theories about our thinking in absence of neurobiological constraints. Neuroscience comprises the study of neuroanatomy, neurophysiology, brain functions and related psychological and computer based models. For years, investigations on a neuronal level were completely separated from those on a cognitive or psychological level. The thinking process is so vast and complex that there are too many conceivable solutions to the problem of how cognitive operation could be accomplished. Neurobiological data provide physical evidence for a theoretical approach to the investigation of cognition. Therefore it narrows the research area and makes it much more exact. The correlation between brain pathology and behaviour supports scientists in their research. It has been known for a long time that different types of brain damage, traumas, lesions, and tumours affect behaviour and cause changes in some mental functions. The rise of new technologies allows us to see and investigate brain structures and processes never seen before. This provides us with a lot of information and material to build simulation models which help us to understand processes in our mind. As neuroscience is not always able to explain all the observations made in laboratories, neurobiologists turn towards Cognitive Psychology in order to find models of brain and behaviour on an interdisciplinary level -- Cognitive Neuropsychology. This "inter-science" as a bridge connects and integrates the two most important domains and their methods of research of the human mind. Research at one level provides constraints, correlations and inspirations for research at another level. ### Neuroanatomy Basics The basic building blocks of the brain are a special sort of cells called neurons. There are approximately 100 billion neurons involved in information processing in the brain. When we look at the brain superficially, we can\'t see these neurons, but rather look at two halves called the hemispheres. The hemispheres themselves may differ in size and function, as we will see later in the book, but principally each of them can be subdivided into four parts called the lobes: the temporal, parietal, occipital and frontal lobe. This division of modern neuroscience is supported by the up- and down-bulging structure of the brain\'s surface. The bulges are called gyri (singular gyrus), the creases sulci (singular sulcus). They are also involved in information processing. The different tasks performed by different subdivisions of the brain as attention, memory and language cannot be viewed as separated from each other, nevertheless some parts play a key role in a specific task. For example the parietal lobe has been shown to be responsible for orientation in space and the relation you have to it, the occipital lobe is mainly responsible for visual perception and imagination etc. Summed up, brain anatomy poses some basic constraints to what is possible for us and a better understanding will help us to find better therapies for cognitive deficits as well as guide research for cognitive psychologists. It is one goal of our book to present the complex interactions between the different levels on which the brain that can be described, and their implications for Cognitive Neuropsychology. ### Methods Newer methods, like EEG and fMRI etc. allow researchers to correlate the behaviour of a participant in an experiment with the brain activity which is measured simultaneously. It is possible to record neurophysiological responses to certain stimuli or to find out which brain areas are involved in the execution of certain mental tasks. EEG measures the electric potentials along the skull through electrodes that are attached to a cap. While its spatial resolution is not very precise, the temporal resolution lies within the range of milliseconds. The use of fMRI benefits from the fact the increased brain activity goes along with increased blood flow in the active region. The haemoglobin in the blood has magnetic properties that are registered by the fMRI scanner. The spatial resolution of fMRI is very precise in comparison to EEG. On the other hand, the temporal resolution is in the range of just 1--2 seconds. ## Conclusion Remember the scenario described at the beginning of the chapter. Knut was asking himself "What is happening here?" It should have become clear that this question cannot be simply answered with one or two sentences. We have seen that the field of Cognitive Psychology comprises a lot of processes and phenomena of which every single one is subject to extensive research to understand how cognitive abilities are produced by our brain. In the following chapters of this WikiBook you will see how the different areas of research in Cognitive Psychology are trying to solve the initial question raised by Knut.
# Cognitive Psychology and Cognitive Neuroscience/Problem Solving from an Evolutionary Perspective +:------------------------------+:----:+------------------------------:+ \| Previous \| O \| [Next \| \| Chapter \| niti \| Social_Cognitions "wikilink") \| \| \| ve_P \| \| \| \| sych \| \| \| \| olog \| \| \| \| y_an \| \| \| \| d_Co \| \| \| \| gnit \| \| \| \| ive_ \| \| \| \| Neur \| \| \| \| osci \| \| \| \| ence \| \| \| \| "wi \| \| \| \| kili \| \| \| \| nk") \| \| +-------------------------------+------+-------------------------------+ ## Introduction Same place, different day. Knut is sitting at his desk again, staring at a blank paper in front of him, while nervously playing with a pen in his right hand. Just a few hours left to hand in his essay and he has not written a word. All of a sudden he smashes his fist on the table and cries out: \"I need a plan!\" That thing Knut is confronted with is something everyone of us encounters in his daily life. He has got a problem -- and he does not really know how to solve it. But what exactly is a problem? Are there strategies to solve problems? These are just a few of the questions we want to answer in this chapter. We begin our chapter by giving a short description of what psychologists regard as a problem. Afterwards we are going to present different approaches towards problem solving, starting with gestalt psychologists and ending with modern search strategies connected to artificial intelligence. In addition we will also consider how experts do solve problems and finally we will have a closer look at two topics: The neurophysiological background on the one hand and the question what kind of role can be assigned to evolution regarding problem solving on the other. The most basic definition is "A problem is any given situation that differs from a desired goal". This definition is very useful for discussing problem solving in terms of evolutionary adaptation, as it allows to understand every aspect of (human or animal) life as a problem. This includes issues like finding food in harsh winters, remembering where you left your provisions, making decisions about which way to go, learning, repeating and varying all kinds of complex movements, and so on. Though all these problems were of crucial importance during the evolutionary process that created us the way we are, they are by no means solved exclusively by humans. We find a most amazing variety of different solutions for these problems in nature (just consider, e.g., by which means a bat hunts its prey, compared to a spider). For this essay we will mainly focus on those problems that are not solved by animals or evolution, that is, all kinds of abstract problems (e.g. playing chess). Furthermore, we will not consider those situations as problems that have an obvious solution: Imagine Knut decides to take a sip of coffee from the mug next to his right hand. He does not even have to think about how to do this. This is not because the situation itself is trivial (a robot capable of recognising the mug, deciding whether it is full, then grabbing it and moving it to Knut's mouth would be a highly complex machine) but because in the context of all possible situations it is so trivial that it no longer is a problem our consciousness needs to be bothered with. The problems we will discuss in the following all need some conscious effort, though some seem to be solved without us being able to say how exactly we got to the solution. Still we will find that often the strategies we use to solve these problems are applicable to more basic problems, too. Non-trivial, abstract problems can be divided into two groups: ### Well-defined Problems For many abstract problems it is possible to find an algorithmic solution. We call all those problems well-defined that can be properly formalised, which comes along with the following properties: - The problem has a clearly defined given state. This might be the line-up of a chess game, a given formula you have to solve, or the set-up of the towers of Hanoi game (which we will discuss later). ```{=html} <!-- --> ``` - There is a finite set of operators, that is, of rules you may apply to the given state. For the chess game, e.g., these would be the rules that tell you which piece you may move to which position. ```{=html} <!-- --> ``` - Finally, the problem has a clear goal state: The equations is resolved to x, all discs are moved to the right stack, or the other player is in checkmate. Not surprisingly, a problem that fulfils these requirements can be implemented algorithmically (also see convergent thinking). Therefore many well-defined problems can be very effectively solved by computers, like playing chess. ### Ill-defined Problems Though many problems can be properly formalised (sometimes only if we accept an enormous complexity) there are still others where this is not the case. Good examples for this are all kinds of tasks that involve creativity, and, generally speaking, all problems for which it is not possible to clearly define a given state and a goal state: Formalising a problem of the kind "Please paint a beautiful picture" may be impossible. Still this is a problem most people would be able to access in one way or the other, even if the result may be totally different from person to person. And while Knut might judge that picture X is gorgeous, you might completely disagree. Nevertheless ill-defined problems often involve sub-problems that can be totally well-defined. On the other hand, many every-day problems that seem to be completely well-defined involve- when examined in detail- a big deal of creativity and ambiguities. If we think of Knut\'s fairly ill-defined task of writing an essay, he will not be able to complete this task without first understanding the text he has to write about. This step is the first subgoal Knut has to solve. Interestingly, ill-defined problems often involve subproblems that are well-defined. ## Restructuring -- The Gestalt Approach One dominant approach to Problem Solving originated from Gestalt psychologists in the 1920s. Their understanding of problem solving emphasises behaviour in situations requiring relatively novel means of attaining goals and suggests that problem solving involves a process called restructuring. Since this indicates a perceptual approach, two main questions have to be considered: - How is a problem represented in a person\'s mind? - How does solving this problem involve a reorganisation or restructuring of this representation? This is what we are going to do in the following part of this section. ### How is a problem represented in the mind? In current research internal and external representations are distinguished: The first kind is regarded as the knowledge and structure of memory, while the latter type is defined as the knowledge and structure of the environment, such like physical objects or symbols whose information can be picked up and processed by the perceptual system autonomously. On the contrary the information in internal representations has to be retrieved by cognitive processes. Generally speaking, problem representations are models of the situation as experienced by the agent. Representing a problem means to analyse it and split it into separate components: - objects, predicates - state space - operators - selection criteria Therefore the efficiency of Problem Solving depends on the underlying representations in a person's mind, which usually also involves personal aspects. Analysing the problem domain according to different dimensions, i.e., changing from one representation to another, results in arriving at a new understanding of a problem. This is basically what is described as restructuring. The following example illustrates this: : Two boys of different age are playing badminton. The older one is a more skilled player, and therefore it is predictable for the outcome of usual matches who will be the winner. After some time and several defeats the younger boy finally loses interest in playing, and the older boy faces a problem, namely that he has no one to play with anymore. : The usual options, according to M. Wertheimer (1945/82), at this point of the story range from \'offering candy\' and \'playing another game\' to \'not playing to full ability\' and \'shaming the younger boy into playing\'. All those strategies aim at making the younger stay. : And this is what the older boy comes up with: He proposes that they should try to keep the bird in play as long as possible. Thus they change from a game of competition to one of cooperation. They\'d start with easy shots and make them harder as their success increases, counting the number of consecutive hits. The proposal is happily accepted and the game is on again. The key in this story is that the older boy restructured the problem and found out that he used an attitude towards the younger which made it difficult to keep him playing. With the new type of game the problem is solved: the older is not bored, the younger not frustrated. Possibly, new representations can make a problem more difficult or much easier to solve. To the latter case insight-- the sudden realisation of a problem's solution -- seems to be related. ### Insight There are two very different ways of approaching a goal-oriented situation. In one case an organism readily reproduces the response to the given problem from past experience. This is called reproductive thinking. The second way requires something new and different to achieve the goal, prior learning is of little help here. Such productive thinking is (sometimes) argued to involve insight. Gestalt psychologists even state that insight problems are a separate category of problems in their own right. Tasks that might involve insight usually have certain features -- they require something new and non-obvious to be done and in most cases they are difficult enough to predict that the initial solution attempt will be unsuccessful. When you solve a problem of this kind you often have a so called \"AHA-experience\" -- the solution pops up all of a sudden. At one time you do not have any ideas of the answer to the problem, you do not even feel to make any progress trying out different ideas, but in the next second the problem is solved. For all those readers who would like to experience such an effect, here is an example for an Insight Problem: Knut is given four pieces of a chain; each made up of three links. The task is to link it all up to a closed loop and he has only 15 cents. To open a link costs 2, to close a link costs 3 cents. What should Knut do? thumbnail=chain task.svg\\|center\\|If you want to know the correct solution, click to enlarge the image. To show that solving insight problems involves restructuring, psychologists created a number of problems that were more difficult to solve for participants provided with previous experiences, since it was harder for them to change the representation of the given situation (see Fixation). Sometimes given hints may lead to the insight required to solve the problem. And this is also true for involuntarily given ones. For instance it might help you to solve a memory game if someone accidentally drops a card on the floor and you look at the other side. Although such help is not obviously a hint, the effect does not differ from that of intended help. For non-insight problems the opposite is the case. Solving arithmetical problems, for instance, requires schemas, through which one can get to the solution step by step. ### Fixation Sometimes, previous experience or familiarity can even make problem solving more difficult. This is the case whenever habitual directions get in the way of finding new directions -- an effect called fixation. #### Functional fixedness Functional fixedness concerns the solution of object-use problems. The basic idea is that when the usual way of using an object is emphasised, it will be far more difficult for a person to use that object in a novel manner. An example for this effect is the candle problem: Imagine you are given a box of matches, some candles and tacks. On the wall of the room there is a cork-board. Your task is to fix the candle to the cork-board in such a way that no wax will drop on the floor when the candle is lit. -- Got an idea? thumbnail=Candle task.svg\\|center\\|The candle task : Explanation: The clue is just the following: when people are confronted with a problem and given certain objects to solve it, it is difficult for them to figure out that they could use them in a different (not so familiar or obvious) way. In this example the box has to be recognised as a support rather than as a container. A further example is the two-string problem: Knut is left in a room with a chair and a pair of pliers given the task to bind two strings together that are hanging from the ceiling. The problem he faces is that he can never reach both strings at a time because they are just too far away from each other. What can Knut do? ![{width="400"} : Solution: Knut has to recognise he can use the pliers in a novel function -- as weight for a pendulum. He can bind them to one of the :strings, push it away, hold the other string and just wait for the first one moving towards him. If necessary, Knut can even climb on the chair, but he is not that small, we suppose . . . #### Mental fixedness Functional fixedness as involved in the examples above illustrates a mental set -- a person's tendency to respond to a given task in a manner based on past experience. Because Knut maps an object to a particular function he has difficulties to vary the way of use (pliers as pendulum\'s weight). One approach to studying fixation was to study wrong-answer verbal insight problems. It was shown that people tend to give rather an incorrect answer when failing to solve a problem than to give no answer at all. : A typical example: People are told that on a lake the area covered by water lilies doubles every 24 hours and that it takes 60 days to cover the whole lake. Then they are asked how many days it takes to cover half the lake. The typical response is \'30 days\' (whereas 59 days is correct). These wrong solutions are due to an inaccurate interpretation, hence representation, of the problem. This can happen because of sloppiness (a quick shallow reading of the problem and/or weak monitoring of their efforts made to come to a solution). In this case error feedback should help people to reconsider the problem features, note the inadequacy of their first answer, and find the correct solution. If, however, people are truly fixated on their incorrect representation, being told the answer is wrong does not help. In a study made by P.I. Dallop and R.L. Dominowski in 1992 these two possibilities were contrasted. In approximately one third of the cases error feedback led to right answers, so only approximately one third of the wrong answers were due to inadequate monitoring.[^1] Another approach is the study of examples with and without a preceding analogous task. In cases such like the water-jug task analogous thinking indeed leads to a correct solution, but to take a different way might make the case much simpler: : Imagine Knut again, this time he is given three jugs with different capacities and is asked to measure the required amount of water. :Of course he is not allowed to use anything despite the jugs and as much water as he likes. In the first case the sizes are: 127 litres, 21 litres and 3 litres while 100 litres are desired. ```{=html} <!-- --> ``` : In the second case Knut is asked to measure 18 litres from jugs of 39, 15 and three litres size. In fact participants faced with the 100 litre task first choose a complicate way in order to solve the second one. Others on the contrary who did not know about that complex task solved the 18 litre case by just adding three litres to 15. ## Problem Solving as a Search Problem The idea of regarding problem solving as a search problem originated from Alan Newell and Herbert Simon while trying to design computer programs which could solve certain problems. This led them to develop a program called General Problem Solver which was able to solve any well-defined problem by creating heuristics on the basis of the user\'s input. This input consisted of objects and operations that could be done on them. As we already know, every problem is composed of an initial state, intermediate states and a goal state (also: desired or final state), while the initial and goal states characterise the situations before and after solving the problem. The intermediate states describe any possible situation between initial and goal state. The set of operators builds up the transitions between the states. A solution is defined as the sequence of operators which leads from the initial state across intermediate states to the goal state. The simplest method to solve a problem, defined in these terms, is to search for a solution by just trying one possibility after another (also called trial and error). As already mentioned above, an organised search, following a specific strategy, might not be helpful for finding a solution to some ill-defined problem, since it is impossible to formalise such problems in a way that a search algorithm can find a solution. As an example we could just take Knut and his essay: he has to find out about his own opinion and formulate it and he has to make sure he understands the sources texts. But there are no predefined operators he can use, there is no panacea how to get to an opinion and even not how to write it down. ### Means-End Analysis In Means-End Analysis you try to reduce the difference between initial state and goal state by creating subgoals until a subgoal can be reached directly (probably you know several examples of recursion which works on the basis of this). An example for a problem that can be solved by Means-End Analysis are the „Towers of Hanoi": Towers of Hanoi -- A well defined problem The initial state of this problem is described by the different sized discs being stacked in order of size on the first of three pegs (the "start-peg"). The goal state is described by these discs being stacked on the third pegs (the "end-peg") in exactly the same order. ![](Tower_of_Hanoi_4.gif "Tower_of_Hanoi_4.gif") There are three operators: - You are allowed to move one single disc from one peg to another one - You are only able to move a disc if it is on top of one stack - A disc cannot be put onto a smaller one. ![](ToH.PNG "ToH.PNG") In order to use Means-End Analysis we have to create subgoals. One possible way of doing this is described in the picture: 1\. Moving the discs lying on the biggest one onto the second peg. 2\. Shifting the biggest disc to the third peg. 3\. Moving the other ones onto the third peg, too You can apply this strategy again and again in order to reduce the problem to the case where you only have to move a single disc -- which is then something you are allowed to do. Strategies of this kind can easily be formulated for a computer; the respective algorithm for the Towers of Hanoi would look like this: 1\. move n-1 discs from A to B 2\. move disc #n from A to C 3\. move n-1 discs from B to C where n is the total number of discs, A is the first peg, B the second, C the third one. Now the problem is reduced by one with each recursive loop. Means-end analysis is important to solve everyday-problems -- like getting the right train connection: You have to figure out where you catch the first train and where you want to arrive, first of all. Then you have to look for possible changes just in case you do not get a direct connection. Third, you have to figure out what are the best times of departure and arrival, on which platforms you leave and arrive and make it all fit together. ### Analogies Analogies describe similar structures and interconnect them to clarify and explain certain relations. In a recent study, for example, a song that got stuck in your head is compared to an itching of the brain that can only be scratched by repeating the song over and over again. ### Restructuring by Using Analogies One special kind of restructuring, the way already mentioned during the discussion of the Gestalt approach, is analogical problem solving. Here, to find a solution to one problem -- the so called target problem, an analogous solution to another problem -- the source problem, is presented. An example for this kind of strategy is the radiation problem posed by K. Duncker in 1945: As a doctor you have to treat a patient with a malignant, inoperable tumour, buried deep inside the body. There exists a special kind of ray, which is perfectly harmless at a low intensity, but at the sufficient high intensity is able to destroy the tumour -- as well as the healthy tissue on his way to it. What can be done to avoid the latter? When this question was asked to participants in an experiment, most of them couldn\'t come up with the appropriate answer to the problem. Then they were told a story that went something like this: A General wanted to capture his enemy\'s fortress. He gathered a large army to launch a full-scale direct attack, but then learned, that all the roads leading directly towards the fortress were blocked by mines. These roadblocks were designed in such a way, that it was possible for small groups of the fortress-owner\'s men to pass them safely, but every large group of men would initially set them off. Now the General figured out the following plan: He divided his troops into several smaller groups and made each of them march down a different road, timed in such a way, that the entire army would reunite exactly when reaching the fortress and could hit with full strength. Here, the story about the General is the source problem, and the radiation problem is the target problem. The fortress is analogous to the tumour and the big army corresponds to the highly intensive ray. Consequently a small group of soldiers represents a ray at low intensity. The solution to the problem is to split the ray up, as the general did with his army, and send the now harmless rays towards the tumour from different angles in such a way that they all meet when reaching it. No healthy tissue is damaged but the tumour itself gets destroyed by the ray at its full intensity. M. Gick and K. Holyoak presented Duncker\'s radiation problem to a group of participants in 1980 and 1983. Only 10 percent of them were able to solve the problem right away, 30 percent could solve it when they read the story of the general before. After given an additional hint -- to use the story as help -- 75 percent of them solved the problem. With this results, Gick and Holyoak concluded, that analogical problem solving depends on three steps: 1\. Noticing that an analogical connection exists between the source and the target problem.\ 2. Mapping corresponding parts of the two problems onto each other (fortress → tumour, army → ray, etc.)\ 3. Applying the mapping to generate a parallel solution to the target problem (using little groups of soldiers approaching from different directions → sending several weaker rays from different directions) Next, Gick and Holyoak started looking for factors that could be helpful for the noticing and the mapping parts, for example: Discovering the basic linking concept behind the source and the target problem. \--\>picture coming soon\<\-- #### Schema The concept that links the target problem with the analogy (the "source problem") is called problem schema. Gick and Holyoak obtained the activation of a schema on their participants by giving them two stories and asking them to compare and summarise them. This activation of problem schemata is called "schema induction". The two presented texts were picked out of six stories which describe analogical problems and their solution. One of these stories was \"The General\" (remember example in Chapter 4.1). After solving the task the participants were asked to solve the radiation problem (see chapter 4.2). The experiment showed that in order to solve the target problem reading of two stories with analogical problems is more helpful than reading only one story: After reading two stories 52% of the participants were able to solve the radiation problem (As told in chapter 4.2 only 30% were able to solve it after reading only one story, namely: "The General"). Gick and Holyoak found out that the quality of the schema a participant developed differs. They classified them into three groups: - Good schemata: In good schemata it was recognised that the same concept was used in order to solve the problem (21% of the participants created a good schema and 91% of them were able to solve the radiation problem). - Intermediate schemata: The creator of an intermediate schema has figured out that the root of the matter equals (here: many small forces solved the problem). (20% created one, 40% of them had the right solution). - Poor schemata: The poor schemata were hardly related to the target problem. In many poor schemata the participant only detected that the hero of the story was rewarded for his efforts (59% created one, 30% of them had the right solution). The process of using a schema or analogy, i.e. applying it to a novel situation is called transduction. One can use a common strategy to solve problems of a new kind. To create a good schema and finally get to a solution is a problem-solving skill that requires practise and some background knowledge. ## How do Experts Solve Problems? With the term expert we describe someone who devotes large amounts of his or her time and energy to one specific field of interest in which he, subsequently, reaches a certain level of mastery. It should not be of surprise that experts tend to be better in solving problems in their field than novices (people who are beginners or not as well trained in a field as experts) are. They are faster in coming up with solutions and have a higher success rate of right solutions. But what is the difference between the way experts and non-experts solve problems? Research on the nature of expertise has come up with the following conclusions: : Experts know more about their field, : their knowledge is organised differently, and : they spend more time analysing the problem. When it comes to problems that are situated outside the experts\' field, their performance often does not differ from that of novices. Knowledge: An experiment by Chase and Simon (1973a, b) dealt with the question how well experts and novices are able to reproduce positions of chess pieces on chessboards when these are presented to them only briefly. The results showed that experts were far better in reproducing actual game positions, but that their performance was comparable with that of novices when the chess pieces were arranged randomly on the board. Chase and Simon concluded that the superior performance on actual game positions was due to the ability to recognise familiar patterns: A chess expert has up to 50,000 patterns stored in his memory. In comparison, a good player might know about 1,000 patterns by heart and a novice only few to none at all. This very detailed knowledge is of crucial help when an expert is confronted with a new problem in his field. Still, it is not pure size of knowledge that makes an expert more successful. Experts also organise their knowledge quite differently from novices. Organisation: In 1982 M. Chi and her co-workers took a set of 24 physics problems and presented them to a group of physics professors as well as to a group of students with only one semester of physics. The task was to group the problems based on their similarities. As it turned out the students tended to group the problems based on their surface structure (similarities of objects used in the problem, e.g. on sketches illustrating the problem), whereas the professors used their deep structure (the general physical principles that underlay the problems) as criteria. By recognising the actual structure of a problem experts are able to connect the given task to the relevant knowledge they already have (e.g. another problem they solved earlier which required the same strategy). Analysis: Experts often spend more time analysing a problem before actually trying to solve it. This way of approaching a problem may often result in what appears to be a slow start, but in the long run this strategy is much more effective. A novice, on the other hand, might start working on the problem right away, but often has to realise that he reaches dead ends as he chose a wrong path in the very beginning. ## Creative Cognition We already introduced a lot of ways to solve a problem, mainly strategies that can be used to find the "correct" answer. But there are also problems which do not require a "right answer" to be given -- It is time for creative productiveness! Imagine you are given three objects -- your task is to invent a completely new object that is related to nothing you know. Then try to describe its function and how it could additionally be used. Difficult? Well, you are free to think creatively and will not be at risk to give an incorrect answer. For example think of what can be constructed from a half-sphere, wire and a handle. The result is amazing: a lawn lounger, global earrings, a sled, a water weigher, a portable agitator, \... [^2] ### Divergent Thinking The term divergent thinking describes a way of thinking that does not lead to one goal, but is open-ended. Problems that are solved this way can have a large number of potential \'solutions\' of which none is exactly \'right\' or \'wrong\', though some might be more suitable than others. Solving a problem like this involves indirect and productive thinking and is mostly very helpful when somebody faces an ill-definedproblem, i.e. when either initial state or goal state cannot be stated clearly and operators or either insufficient or not given at all. The process of divergent thinking is often associated with creativity, and it undoubtedly leads to many creative ideas. Nevertheless, researches have shown that there is only modest correlation between performance on divergent thinking tasks and other measures of creativity. Additionally it was found that in processes resulting in original and practical inventions things like searching for solutions, being aware of structures and looking for analogies are heavily involved, too. Thus, divergent thinking alone is not an appropriate tool for making an invention. You also need to analyse the problem in order to make the suggested, i.e. invention, solution appropriate. #### right or wrong The ability of children to imitate the people and the surrounding environment also influential in recognizing the concepts of right and wrong To introduce the concepts of right and wrong must be seen from the age of the child. When children are a year old, their brains are not fully developed so their understanding is still limited. But keep in mind, too, from an early age the average child is able to imitate parents, see their surroundings and do imitation or called modeling. Therefore, the introduction of the concept of right and wrong also depends on how the parents or other adults live with the child. \"If a mother often sits on the couch while raising both legs, children tend to sit with more or less the same style and think this is true. As we get older, modeling is the most natural thing that children can get about right and wrong,\" said this psychologist called Kiki. The method of giving understanding about the concepts of right and wrong is also adjusted to the age of the child. If children are still toddlers, they can go through activities such as telling stories that are rich in social values. Slip conclusions at the end of a fairy tale. \"For example, the Kancil tale, after storytelling parents can say, \'So, stealing is not good\', to emphasize the moral message in the fairy tale,\" said the psychologist from the Indonesian Psychological Practice Foundation, Bintaro, South Jakarta. For children who are older, for example in primary school age and still under 12 years of age, understanding can be given by giving an explanation of their eyes. Because the nature of them still tends to be egocentric. However, when entering adolescence, giving an explanation can be through a general perspective, especially cause and effect. \"When giving to tell children about the concepts of right and wrong, parents need to pay attention to whether the child really understands the message that was delivered as a whole or only part of the contents of the message,\" Kiki added. For example, when parents want to teach the concept of stealing is not good through the story of Kancil, parents must make sure the child understands that anyone should not steal, no matter what the circumstances. Do not let the child who understands that is not allowed to steal a mouse deer or that should not be stolen is cucumber. Therefore, ask the child to explain his understanding once more so that the child is sure to understand. Responsible Learning If you have been taught the concept of right and wrong, but the child still violates it, parents must act and the child needs to know the consequences of the wrong actions. \"For example, it was explained that you should not pick rambutan from a neighboring tree, but the child still did it, immediately reprimanded firmly and words that were not ambiguous or ambiguous, but still polite. \"However, the child must be responsible for his attitude,\" Kiki reminded. Of course, continued Kiki, all this depends on the age of the child. In a small age for certain things, it is better for parents to stay with children, but when they are older, children need to know that parents will not risk their mistakes. Children who from childhood have understood between right and wrong will grow into individuals who are independent, responsible and well-mannered. This will also make it easier for them to socialize in their environment, have healthy friendships and make it easier for them to get good jobs because employers and coworkers certainly want to work with people who are polite, honest and responsible. Important to remember The following basic things can be done by parents to instill in children the right behavior - To say thanks - Say a word please if you want to ask for help - apologize if wrong, even to the child if the parents are wrong - Say greetings ### Convergent Thinking Convergent thinking patterns are problem solving techniques that unite different ideas or fields to find a solution. The focus of this mindset is speed, logic and accuracy, also identification of facts, reapplying existing techniques, gathering information. The most important factor of this mindset is: there is only one correct answer. You only think of two answers, namely right or wrong. This type of thinking is associated with certain science or standard procedures. People with this type of thinking have logical thinking, are able to memorize patterns, solve problems and work on scientific tests. Most school subjects sharpen this type of thinking ability. Research shows that the creative process involves both types of thought processes. But experts recommend not joining the two processes in one session. For example, in the next 30 minutes, you invite everyone on your team to brainstorm creating new ideas (which involve divergent thinking patterns). Within 30 minutes, all ideas should only be recorded, not judged, for example by saying that an idea is irrelevant because of a limited budget. After all the ideas are contained, go to the next session, namely analysis and decision making (which involves convergent thinking patterns). Based on research too, doing creative jobs causes mood swings (mood swings), and it turns out that both types of thinking create two different moods. Convergent thinking patterns create negative moods, while divergent thinking patterns create a positive mood. J.A. Research Horne in 1988 revealed that lack of sleep will greatly affect the performance of people with divergent thought patterns, whereas people with convergent mindsets will be more likely to be fine. Including which mindset do you have? Use wisely your talents, and practice both types of thinking to be able to use them in balance at the right times. ## Neurophysiological Background Presenting Neurophysiology in its entirety would be enough to fill several books. Fortunately we do not have to concern ourselves with most of these facts. Instead, let\'s just focus on the aspects that are really relevant to problem solving. Nevertheless this topic is quite complex and problem solving cannot be attributed to one single brain area. Rather there are systems of several brain areas working together to perform a specific task. This is best shown by an example: : In 1994 Paolo Nichelli and coworkers used the method of PET (Positron Emission Tomography), to localise certain brain areas, which are involved in solving various chess problems. In the following table you can see which brain area was active during a specific task: +----------------------------------+----------------------------------+ \| Task \| Location of Brain activity \| +==================================+==================================+ \| - Identifying chess pieces \| - Pathway from Occipital to \| \| \| Temporal Lobe \| \| ```{=html} \| \| \| <!-- --> \| (also called the \| \| ``` \| \"what\"-pathway of visual \| \| - determining location of \| processing) \| \| pieces \| \| \| \| - Pathway from Occipital to \| \| ```{=html} \| parietal Lobe \| \| <!-- --> \| \| \| ``` \| (also called the \| \| - Thinking about making a move \| \"where\"-pathway of visual \| \| \| processing) \| \| ```{=html} \| \| \| <!-- --> \| - Premotor area \| \| ``` \| \| \| - Remembering a pieces move \| ```{=html} \| \| \| <!-- --> \| \| ```{=html} \| ``` \| \| <!-- --> \| - Hippocampus \| \| ``` \| \| \| - Planning and executing \| (forming new memories) \| \| strategies \| \| \| \| - Prefrontal cortex \| +----------------------------------+----------------------------------+ framed\\|center\\|Lobes of the Brain One of the key tasks, namely planning and executing strategies, is performed by a brain area which also plays an important role for several other tasks correlated with problem solving -- the prefrontal cortex (PFC). This can be made clear if you take a look at several examples of damages to the PFC and their effects on the ability to solve problems.\ Patients with a lesion in this brain area have difficulty switching from one behaviouristic pattern to another. A well known example is the wisconsin card-sorting task. A patient with a PFC lesion who is told to separate all blue cards from a deck, would continue sorting out the blue ones, even if the experimenter told him to sort out all brown cards. Transferred to a more complex problem, this person would most likely fail, because he is not flexible enough to change his strategy after running into a dead end.\ Another example is the one of a young homemaker, who had a tumour in the frontal lobe. Even though she was able to cook individual dishes, preparing a whole family meal was an infeasible task for her. As the examples above illustrate, the structure of our brain seems to be of great importance regarding problem solving, i.e. cognitive life. But how was our cognitive apparatus designed? How did perception-action integration as a central species specific property come about? ## The Evolutionary Perspective Charles Darwin developed the evolutionary theory which was primarily meant to explain why there are so many different kinds of species. This theory is also important for psychology because it explains how species were designed by evolutionary forces and what their goals are. By knowing the goals of species it is possible to explain and predict their behaviour. The process of evolution involves several components, for instance natural selection -- which is a feedback process that \'chooses\' among \'alternative designs\' on the basis of deciding how good the respective modulation is. As a result of this natural selection we find adaption. This is a process that constantly tests the variations among individuals in relation to the environment. If adaptions are useful they get passed on; if not they'll just be an unimportant variation. Another component of the evolutionary process is sexual selection, i.e. increasing of certain sex characteristics, which give individuals the ability to rival with other individuals of the same sex or an increased ability to attract individuals of the opposite sex. Altruism is a further component of the evolutionary process, which will be explained in more detail in the following chapter Evolutionary Perspective on Social Cognitions. ## Summary and Conclusion After Knut read this WikiChapter he was relieved that he did not waste his time for the essay -- quite the opposite! He now has a new view on problem solving -- and recognises his problem as a well-defined one: His initial state was the clear blank paper without any philosophical sentences on it. The goal state was just in front of his mind\'s eye: Him -- grinning broadly -- handing in the essay with some carefully developed arguments. He decides to use the technique of Means-End Analysis and creates several subgoals: : 1\. Read important passages again : 2\. Summarise parts of the text : 3\. Develop an argumentative structure : 4\. Write the essay : 5\. Look for typos Right after he hands in his essay Knut will go on reading this WikiBook. He now looks forward to turning the page over and to discovering the next chapter\... ## References ```{=html} <references /> ``` ## External links - Mental Models, by Philip N. Johnson-Laird ## Organizational Stuff - send eMail to all - anwinkle - benkuest - lkaestne - nmoeller - tgrage [^1]: R.L. Dominowski and P. Dallob, Insight and Problem Solving. In The Nature of Insight, R.J. Sternberg & J.E. Davidson (Eds). MIT Press: USA, pp.33-62 (1995). [^2]: Goldstein, E.B. (2005). Cogntive Psychology. Connecting Mind, Research, and Everyday Experience. Belmont: Thomson Wadsworth.
# Cognitive Psychology and Cognitive Neuroscience/Evolutionary Perspective on Social Cognitions +:------------------------------+:----:+------------------------------:+ \| Previous \| O \| [Next \| \| C \| verv \| Chapter \| \| onary_Perspective "wikilink") \| ve_P \| \| \| \| sych \| \| \| \| olog \| \| \| \| y_an \| \| \| \| d_Co \| \| \| \| gnit \| \| \| \| ive_ \| \| \| \| Neur \| \| \| \| osci \| \| \| \| ence \| \| \| \| "wi \| \| \| \| kili \| \| \| \| nk") \| \| +-------------------------------+------+-------------------------------+ ## Introduction ![{width="101"} Why do we live in cities? Why do we often choose to work together? Why do we enjoy sharing our spare time with others? These are questions of Social Cognition and its evolutionary development. The term Social Cognition describes all abilities necessary to act adequately in a social system. Basically, it is the study of how we process social information, especially its storage, retrieval and application to social situations. Social Cognition is a common skill among various species. In the following, the focus will be on Social Cognition as a human skill. Important concepts and the development during childhood will be explained. Having built up a conceptional basis for the term, we will then take a look at this skill from an evolutionary perspective and present the common theories on the origin of Social Cognition. The publication of Michael Tomasello et al. in the journal Behavioral and Brain Sciences (2005) [^1] will serve as a basis for this chapter. ## Social Cognition ### The human faculty of Social Cognition thumb\\|Playing football as a complex social activity Humans are by far the most talented species in reading the minds of others. That means we are able to successfully predict what other humans perceive, intend, believe, know or desire. Among these abilities, understanding the intention of others is crucial. It allows us to resolve possible ambiguities of physical actions. For example, if you were to see someone breaking a car window, you would probably assume he was trying to steal a stranger\'s car. He would need to be judged differently if he had lost his car keys and it was his own car that he was trying to break into. Humans also collaborate and interact culturally. We perform complex collaborative activities, like building a house together or playing football as a team. Over time this led to powerful concepts of organizational levels like societies and states. The reason for this intense development can be traced back to the concept of Shared Intentionality. ### Shared Intentionality An intentional action is an organism\'s intelligent behavioural interaction with its environment towards a certain goal state. This is the concept of Problem Solving, which was already described in the previous chapter. The social interaction of agents in an environment which understand each other as acting intentionally causes the emergence of Shared Intentionality. This means that the agents work together towards a shared goal in collaborative interaction. They do that in coordinated action roles and mutual knowledge about themselves. The nature of the activity or its complexity is not important, as long as the action is carried out in the described fashion. It is important to mention that the notion of shared goals means that the internal goals of each agent include the intentions of the others. This can easily be misinterpreted. For example, take a group of apes on a hunt. They appear to be acting in a collaborative way, however, it is reasonable to assume that they do not have coordinated action roles or a shared goal -- they could just be acting towards the same individual goal. Summing up, the important characteristics of the behaviour in question are that the agents are mutually responsive, have the goal of achieving something together and coordinate their actions with distributed roles and action plans. The strictly human faculty to participate in collaborative actions that involve shared goals and socially coordinated action plans is also called Joint Intention. This requires an understanding of the goals and perceptions of other involved agents, as well as sharing and communicating these, which again seems to be a strictly human behaviour. Due to our special motivation to share psychological states, we also need certain complex cognitive representations. These representations are called dialogic cognitive representations, because they have as content mostly social engagement. This is especially important for the concept of joint intentions, since we need not only a representation for our own action plan, but also for our partner\'s plan. Joint Intentions are an essential part of Shared Intentionality. Dialogic cognitive representations are closely related with the communication and use of linguistic symbols. They allow in some sense a form of collective intentionality, which is important to construct social norms, conceptualize beliefs and, most importantly, share them. In complex social groups the repeated sharing of intentions in a particular interactive context leads to the creation of habitual social practices and beliefs. That may form normative or structural aspects of a society, like government, money, marriage, etc. Society might hence be seen as a product and an indicator of Social Cognition. The social interaction that builds ground for activities involving Shared Intentionality is proposed to be divided into three groups: - Dyadic engagement: The simple sharing of emotions and behaviour, by means of interaction and direct mutual response between agents. Dyadic interaction between human infants and adults are called protoconversations. These are turn-taking sequences of touching, face expressions and vocalisations. The exchange of emotions is the most important outcome of this interaction. ```{=html} <!-- --> ``` - Triadic engagement: Two agents act together towards a shared goal, while monitoring the perception and goal-direction of the other agent. They focus on the same problem and coordinate their actions respectively, which makes it possible to predict following events. ```{=html} <!-- --> ``` - Collaborative engagement: The combination of Joint Intentions and attention. At this point, the agents share a goal and act in complementary roles with a complex action plan and mutual knowledge about the selective attention and the intentions of one another. The latter aspect allows the agents to assist each other and reverse or take over roles. These different levels of social engagement require the understanding of different aspects of intentional action, as introduced above, and presuppose the motivation to share psychological states with each other. ### Development of Social Cognition during childhood !Children making social experiences{width="150"} A crucial point for Social Cognition is the comprehension of intentional action. Children\'s understanding of intentional action can basically be divided into three groups, each representing a more complex level of grasp. 1. The first one to be mentioned is the identification of animate action. This means that after a couple of months, babies can differentiate between motion that was caused by some external influence and actions that an organism has performed by itself, as an animate being. At this stage, however, the child has not yet any understanding of potential goals the observed actor might have, so it is still incapable of predicting the behaviour of others. 2. The next stage of comprehension includes the understanding that the organism acts with persistence towards achieving a goal. Children can now distinguish accidental incidents from intentional actions and failed from successful attempts. This ability develops after about 9 months. With this new perspective, the child also learns that the person it observes has a certain perception - thus a certain amount of predicting behaviour is possible. This is an essential difference between the first and the second stage. 3. After around 14 months of age, children fully comprehend intentional action and the basics of rational decision making. They realise, that an actor pursuing a goal may have a variety of action plans to achieve a goal, and is choosing between them. Furthermore, a certain sense for the selective attention of an agent develops. This allows a broad variety of predictions of behaviour in a certain environment. In addition to that, children acquire the skill of cultural learning: when they observe how an individual successfully reaches a goal, they memorise the procedure. Hence, they can use the methods to reach their own goals. This is called imitative learning, which turns out to be an extremely powerful tool. By applying this technique, children also learn how things are conventionally done in their culture. ## Evolutionary perspective on Social Cognition So far we discussed what Social Cognition is about. But how could this behaviour develop during evolution? At first glance, Darwin's theory of the survival of the fittest does not support the development of social behaviour. Caring for others, and not just for oneself, seems to be a decrease of fitness. Nevertheless, various theories have been formulated which try to explain Social Cognition from an evolutionary perspective. We will present three influential theories which have been formulated by Steven Gaulin and Donald McBurney.[^2] ### Group Selection thumb\\|Moai at Rano Raraku Vero Wynne-Edwards first proposed this theory in the 1960s. From an evolutionary perspective, a group is a number of individuals which affect the fitness of each other. Group Selection means that if any of the individuals of a group is doing benefit to its group, the group is more likely to survive and pass on its predisposition to the next generation. This again improves the chance of the individual to spread its genetic material. So in this theory a social organism is more likely to spread its genes than a selfish organism. The distinction to the classical theory of evolution is that not only the fittest individuals are likely to survive, but also the fittest groups. An example would be the history of the Rapa Nui. The Rapa Nui were the natives of Easter Island which handled their resources extremely wasteful in order to build giant heads made of stone. After a while, every tree on the island was extinct because they needed the trunks to transport the stones. The following lack of food led to the breakdown of their civilization. A society which handles their resources more moderate and provident would not have ended up in such a fate. However, if both societies would have lived on one island, the second group would not have been able to survive because they would not have been able to keep the resources. This indicates the problem of the Group Selection: it needs certain circumstances to describe things properly. Additionally, every theory about groups should include the phenomenon of migration. So in this simple form, the theory is not capable of handling selfish behaviour of some agents in altruistic groups: Altruistic groups which include selfish members would turn into pure selfish ones over time, because altruistic agents would work for selfish agents, thereby increasing the cheaters\' fitness while decreasing their own. Thus, Group Selection may not be a sufficient explanation for the development of Social Cognition. ### Kin Selection Since altruistic populations are vulnerable to cheaters, there must exist a mechanism that allows altruism to be maintained by natural selection. The Kin Selection approach provides an explanation how altruistic genes can spread without being eliminated by selfish behaviour. The theory was developed by William D. Hamilton and John M. Smith in 1964.[^3] The basic principle of Kin Selection is to benefit somebody who is genetically related, for example by sharing food. For the altruistic individual, this means a reduction of its own fitness by increasing the fitness of its relative. However, the closer the recipient is related to the altruist, the more likely he shares the altruistic genes. The loss of fitness can be compensated since the genes of the altruistically behaving agent have then the chance to be spread indirectly through the recipient: The relative might be able to reproduce and pass the altruistic genes over to the next generation. In principle, the disadvantage for the giver should always be less than the increased fitness of the addressee. This relation between costs and benefit is expressed by Hamilton\'s rule taking additionally the relatedness of altruist and recipient into account: ```{=html} <center> ``` $r \cdot b > c$ ```{=html} </center> ``` !Ant colonies provide evidence for Kin Selection where : r shows the genetic relatedness between altruist and recipient (coefficient between zero and one), ```{=html} <!-- --> ``` : b is the reproductive benefit or increased fitness for the recipient and ```{=html} <!-- --> ``` : c are the altruist\'s reproductive costs or the reduction of his fitness in the performed action. If the product of relatedness and benefit outweighs the costs for the giver, the altruistic action should be performed. The closer the recipient is genetically related, the higher costs are acceptable. Examples for kin-selected altruism can be found in populations of social insects like ants, termites or bees. An ant colony, for instance, consists of one fertile queen and several hundreds or more of sterile female workers. While the queen is the only one reproducing, the workers are among other things responsible for brood care. The workers are genetically closer related to the sisters they raise (75%) than they would be to their own offspring (50%). Therefore, they are passing on more of their genes than if they bred on their own. According to Hamilton\'s rule, altruism is only favoured if directed towards relatives, that is $r > 0$. Therefore, Kin Selection theory accounts only for genetic relatives. Altruism however occurs among not related individuals as well. This issue is addressed by the theory of Reciprocal Altruism. ### Reciprocal Altruism The theory of Reciprocal Altruism describes beneficial behaviour in expectation of future reciprocity. This form of altruism is not a selfless concern for the welfare of others but it denotes mutual cooperation of repeatedly interacting species in order to maximise their individual utility. In social life an individual can benefit from mutual cooperation, but each one can also do even better by exploiting the cooperative efforts of others. Game Theory allows a formalisation of the strategic possibilities in such situations. It can be shown, that altruistic behaviour can be more successful (in terms of utility) than purely self-interested strategies and therefore will lead to better fitness and survivability. In many cases social interactions can be modelled by the Prisoner\'s Dilemma, which provides the basis of our analysis. The classical prisoner\'s dilemma is as follows: Knut and his friend are arrested by the police. The police has insufficient evidence for a conviction, and, having separated both prisoners, visits each of them to offer the same deal: if one testifies for the prosecution against the other and the other remains silent, the betrayer goes free and the silent accomplice receives the full ten-year sentence. If both stay silent, the police can sentence both prisoners to only six months in jail for a minor charge. If each betrays the other, each will receive a two-year sentence. Prisoner 1 / Prisoner 2 Cooperate Defect ------------------------- ----------------- ----------------- Cooperate 6 months each 10 years / free Defect free / 10 years 2 years each : Possible outcomes of the Prisoner\'s Dilemma: Each prisoner has two strategies to choose from, to remain silent (cooperate) or to testify (defect). Assume Knut wants to minimize his individual durance. If Knut\'s friend cooperates, it is better to defect and go free than to cooperate and spend six months in jail. If Knut\'s friend defects, then Knut should defect too, because two years in jail are better than ten. The same holds for the other prisoner. So defection is the dominant strategy in the prisoner\'s dilemma, even though both would do better, if they cooperated. In a one-shot game a rational player would always defect, but what happens if the game is played repeatedly? One of the most effective strategies in the iterated prisoner\'s dilemma is the mixed strategy called Tit for Tat: Always cooperate in the first game, then do whatever your opponent did in the previous game. Playing Tit for Tat means to maintain cooperation as long as the opponent does. If the opponent defects he gets punished in succeeding games by defecting likewise until cooperation is restored. With this strategy rational players can sustain the cooperative outcome at least for indefinitely long games (like life).[^4] Clearly Tit for Tat is only expected to evolve in the presence of a mechanism to identify and punish cheaters. Assuming species are not able to choose between different strategies, but rather that their strategical behaviour is hard-wired, we can finally come back to the evolutionary perspective. In The Evolution of Cooperation Robert Axelrod formalised Darwin\'s emphasis on individual advantage in terms of game theory.[^5] Based on the concept of an evolutionary stable strategy in the context of the prisoner\'s dilemma game he showed how cooperation can get started in an asocial world and can resist invasion once fully established. ## Conclusion Summing up, Social Cognition is a very complex skill and can be seen as the fundament of our current society. On account of the concept of Shared Intentionality, humans show by far the most sophisticated form of social cooperation. Although it may not seem obvious, Social Cognition can actually be compatible with the theory of evolution and various reasonable approaches can be formulated. These theories are all based on a rather selfish drive to pass on our genetic material - so it may be questionable, if deep-rooted altruism and completely selfless behaviour truly exists. ## References ```{=html} <references/> ``` [^1]: Tomasello, M. et al (2005). Understanding and sharing intentions: The origins of cultural cognition. Behavioral and Brain Sciences, 28(5), 675--735. [^2]: Gaulin, S. J. C, & McBurney, D. H. (2003). Evolutionary Psychology. New Jersey: Prentice-Hall. [^3]: Hamilton, W. D. (1964). The genetical evolution of social behaviour I and II. Journal of Theoretical Biology, 7, 17-52. [^4]: Aumann, R. J. (1959). Acceptable Points in General Cooperative n-Person Games. Contributions to the Theory of Games IV, Annals of Mathematics Study, 40, 287-324. [^5]: Axelrod, R. (1984). The Evolution of Cooperation. New York: Basic Books.
# Cognitive Psychology and Cognitive Neuroscience/Behavioural and Neuroscience Methods +:------------------------------+:----:+------------------------------:+ \| Previous \| [O \| [Next \| \| Chapter \| niti \| ation_and_Emotion "wikilink") \| \| \| ve_P \| \| \| \| sych \| \| \| \| olog \| \| \| \| y_an \| \| \| \| d_Co \| \| \| \| gnit \| \| \| \| ive_ \| \| \| \| Neur \| \| \| \| osci \| \| \| \| ence \| \| \| \| "wi \| \| \| \| kili \| \| \| \| nk") \| \| +-------------------------------+------+-------------------------------+ ## Introduction !Ct-Scan !human brain lobes Behavioural and Neuroscientific methods are used to gain insight into how the brain influences the way individuals think, feel, and act. There are an array of methods, which can be used to analyze the brain and its relationship to behavior. Well-known techniques include EEG (electroencephalography) which records the brain's electrical activity and fMRI (functional magnetic resonance imaging) which produces detailed images of brain structure and/or activity. Other methods, such as the lesion method, are lesser known, but still influential in today\'s neuroscience research. Methods can be organized into the following categories: anatomical, physiological, and functional. Other techniques include modulating brain activity, analyzing behavior or computational modeling. ## Lesion method In the lesion method, patients with brain damage are examined to determine which brain structures are damaged and how this influences the patient\'s behavior. Researchers attempt to correlate a specific brain area to an observed behavior by using reported experiences and research observations. Researchers may conclude that the loss of functionality in a brain region causes behavioral changes or deficits in task performance. For example, a patient with a lesion in the parietal-temporal-occipital association area will exhibit agraphia, a condition in which he/she is not able to write, despite having no deficits in motor ability. If damage to a particular brain region (structure X) is shown to correlate with a specific change in behavior (behavior Y), researchers may deduce that structure X has a relation to behavior Y. In humans, lesions are most often caused by tumors or strokes. Through current brain imaging technologies, it is possible to determine which area was damaged during a stroke. Loss of function in the stroke victim may then be correlated with that damaged brain area. While lesion studies in humans have provided key insights into brain organization and function, lesions studies in animals offer many advantages. First, animals used in research are reared in controlled environmental conditions that limit variability between subjects. Secondly, researchers are able to measure task performance in the same animal, before and after a lesion. This allows for within-subject comparison. And third the control groups can be watched who either did not undergo surgery or who did have surgery in another brain area. These benefits also increase the accuracy of the hypothesis being tested which is more difficult in human research because the before-after comparison and control experiments drop out. !Visualization of iron rod passing through brain of Phineas Gage.gif "Visualization of iron rod passing through brain of Phineas Gage"){width="220"} To strengthen conclusions regarding a brain area and task performance, researchers may perform double dissociation. The goal of this method is to prove that two dissociations are independent. Through comparison of two patients with differing brain damage and contradictory disease patterns, researchers may localize different behaviors to each brain area. Broca\'s area is a region of the brain is responsible for language processing, comprehension and speech production. Patients with a lesion in Broca\'s area will exhibit Broca\'s aphasia or non-fluent aphasia. These patients are unable to speak fluently; a sentence produced by a patient with damage to the Broca\'s area may sound like: \"I \... er \... wanted \... ah \... well \... I \... wanted to \... er \... go surfing \... and ..er \... well\...\". On the other hand, Wernicke\'s area is responsible for speech comprehension. A patient with a lesion in this area has Wernicke\'s aphasia. They may be able to produce language, but lack the ability to produce meaningful sentences. Patients may produce \'word salad\': \" I then did this chingo for some hours after my dazi went through meek and been sharko\". Patients with Wernicke\'s aphasia are often unaware of speech deficits and may believe that they are speaking properly. Certainly one of the famous \"lesion\" cases was that of Phineas Gage. On 13 September 1848 Gage, a railroad construction foreman, was using an iron rod to tamp an explosive charge into a body of rock when premature explosion of the charge blew the rod through his left jaw and out the top of his head. Miraculously, Gage survived, but reportedly underwent a dramatic personality change as a result of destruction of one or both of his frontal lobes. The uniqueness of Gage case (and the ethical impossibility of repeating the treatment in other patients) makes it difficult to draw generalizations from it, but it does illustrate the core idea behind the lesion method. Further problems stem from the persistent distortions in published accounts of Gage---see the Wikipedia article Phineas Gage. ## Techniques for Assessing Brain Anatomy / Physiological Function ### CAT !X-ray picture.{width="200"} CAT scanning was invented in 1972 by the British engineer Godfrey N. Hounsfield and the South African (later American) physicist Alan Cromack. CAT (Computed Axial Tomography) is an x-ray procedure which combines many x-ray images with the aid of a computer to generate cross-sectional views, and when needed 3D images of the internal organs and structures of the human body. A large donut-shaped x-ray machine takes x-ray images at many different angles around the body. Those images are processed by a computer to produce cross-sectional picture of the body. In each of these pictures the body is seen as an x-ray 'slice' of the body, which is recorded on a film. This recorded image is called a tomogram. CAT scans are performed to analyze, for example, the head, where traumatic injuries (such as blood clots or skull fractures), tumors, and infections can be identified. In the spine the bony structure of the vertebrae can be accurately defined, as can the anatomy of the spinal cord. CAT scans are also extremely helpful in defining body organ anatomy, including visualizing the liver, gallbladder, pancreas, spleen, aorta, kidneys, uterus, and ovaries. The amount of radiation a person receives during a CAT scan is minimal. In men and non-pregnant women it has not been shown to produce any adverse effects. However, doing a CAT test hides some risks. If the subject or the patient is pregnant it maybe recommended to do another type of exam to reduce the possible risk of exposing her fetus to radiation. Also in cases of asthma or allergies it is recommended to avoid this type of scanning. Since the CAT scan requires a contrast medium, there\'s a slight risk of an allergic reaction to the contrast medium. Having certain medical conditions; Diabetes, asthma, heart disease, kidney problems or thyroid conditions also increases the risk of a reaction to contrast medium. ### MRI Although CAT scanning was a breakthrough, in many cases it was substituted by magnetic resonance imaging (MRI), a method of looking inside the body without using x-rays, harmful dyes or surgery. Instead, radio waves and a strong magnetic field are used in order to provide remarkably clear and detailed pictures of internal organs and tissues. !MRI head side{width="200"} History and Development of MRI MRI is based on a physics phenomenon called nuclear magnetic resonance (NMR), which was discovered in the 1930s by Felix Bloch (working at Stanford University) and Edward Purcell (from Harvard University). In this resonance, magnetic field and radio waves cause atoms to give off tiny radio signals. In the year 1970, Raymond Damadian, a medical doctor and research scientist, discovered the basis for using magnetic resonance imaging as a tool for medical diagnosis. Four years later a patent was granted, which was the world\'s first patent issued in the field of MRI. In 1977, Dr. Damadian completed the construction of the first "whole-body" MRI scanner, which he called the "Indomitable". The medical use of magnetic resonance imaging has developed rapidly. The first MRI equipment in healthcare was available at the beginning of the 1980s. In 2002, approximately 22,000 MRI scanners were in use worldwide, and more than 60 million MRI examinations were performed. !A full size MRI-Scanner.{width="250"} Common Uses of the MRI Procedure Because of its detailed and clear pictures, MRI is widely used to diagnose sports-related injuries, especially those affecting the knee, elbow, shoulder, hip and wrist. Furthermore, MRI of the heart, aorta and blood vessels is a fast, non-invasive tool for diagnosing artery disease and heart problems. The doctors can even examine the size of the heart-chambers and determine the extent of damage caused by a heart disease or a heart attack. Organs like lungs, liver or spleen can also be examined in high detail with MRI. Because no radiation exposure is involved, MRI is often the preferred diagnostic tool for examination of the male and female reproductive systems, pelvis and hips and the bladder. Risks An undetected metal implant may be affected by the strong magnetic field. MRI is generally avoided in the first 12 weeks of pregnancy. Scientists usually use other methods of imaging, such as ultrasound, on pregnant women unless there is a strong medical reason to use MRI. ### PPT MRIII !Reconstruction of nerve fibers{width="220"} There has been some further development of the MRI: The DT-MRI (diffusion tensor magnetic resonance imaging) enables the measurement of the restricted diffusion of water in tissue and gives a 3-dimensional image of it. History: The principle of using a magnetic field to measure diffusion was already described in 1965 by the chemist Edward O. Stejskal and John E. Tanner. After the development of the MRI, Michael Moseley introduced the principle into MR Imaging in 1984 and further fundamental work was done by Dennis LeBihan in 1985. In 1994 the engineer Peter J. Basser published optimized mathematical models of an older diffusion-tensor model.[^1] This model is commonly used today and supported by all new MRI-devices. The DT-MRI technique takes advantage of the fact that the mobility of water molecules in brain tissue is restricted by obstacles like cell membranes. In nerve fibers mobility is only possible alongside the axons. So measuring the diffusion gives rise to the course of the main nerve fibers. All the data of one diffusion-tensor are too much to process in a single image, so there are different techniques for visualization of different aspects of this data: - Cross section images - tractography (reconstruction of main nerve fibers) - tensor glyphs (complete illustration of diffusion-tensor information) The diffusion manner changes by patients with specific diseases of the central nervous system in a characteristic way, so they can be discerned by the diffusion-tensor technique. Diagnosis of apoplectic strokes and medical research of diseases involving changes of the white matter, like Alzheimer\'s disease or Multiple sclerosis are the main applications. Disadvantages of DT-MRI are that it is far more time consuming than ordinary MRI and produces large amounts of data, which first have to be visualized by the different methods to be interpreted. ### fMRI The fMRI (Functional Magnetic Resonance) Imaging is based on the Nuclear magnetic resonance (NMR). The way this method works is the following: All atomic nuclei with an odd number of protons have a nuclear spin. A strong magnetic field is put around the tested object which aligns all spins parallel or antiparallel to it. There is a resonance to an oscillating magnetic field at a specific frequency, which can be computed in dependence on the atom type (the nuclei's usual spin is disturbed, which induces a voltage s (t), afterwards they return to the equilibrium state). At this level different tissues can be identified, but there is no information about their location. Consequently the magnetic field's strength is gradually changed, thereby there is a correspondence between frequency and location and with the help of Fourier analysis we can get one-dimensional location information. Combining several such methods as the Fourier analysis it is possible to get a 3D image. !fMRI picture{width="270"} The central idea for fMRI is to look at the areas with increased blood flow. Hemoglobin disturbs the magnetic imaging, so areas with an increased blood oxygen level dependant (BOLD) can be identified. Higher BOLD signal intensities arise from decreases in the concentration of deoxygenated haemoglobin. An fMRI experiment usually lasts 1-2 hours. The subject will lie in the magnet and a particular form of stimulation will be set up and MRI images of the subject\'s brain are taken. In the first step a high resolution single scan is taken. This is used later as a background for highlighting the brain areas which were activated by the stimulus. In the next step a series of low resolution scans are taken over time, for example, 150 scans, one every 5 seconds. For some of these scans, the stimulus will be presented, and for some of the scans, the stimulus will be absent. The low resolution brain images in the two cases can be compared, to see which parts of the brain were activated by the stimulus. The rest of the analysis is done using a series of tools which correct distortions in the images, remove the effect of the subject moving their head during the experiment, and compare the low resolution images taken when the stimulus was off with those taken when it was on. The final statistical image shows up bright in those parts of the brain which were activated by this experiment. These activated areas are then shown as coloured blobs on top of the original high resolution scan. This image can also be rendered in 3D. fMRI has moderately good spatial resolution and bad temporal resolution since one fMRI frame is about 2 seconds long. However, the temporal response of the blood supply, which is the basis of fMRI, is poor relative to the electrical signals that define neuronal communication. Therefore, some research groups are working around this issue by combining fMRI with data collection techniques such as electroencephalography (EEG) or magneto encephalography (MEG), which has much higher temporal resolution but rather poorer spatial resolution. ### PET Positron emission tomography, also called PET imaging or a PET scan, is a diagnostic examination that involves the acquisition of physiologic images based on the detection of radiation from the emission of positrons. It is currently the most effective way to check for cancer recurrences. Positrons are tiny particles emitted from a radioactive substance administered to the patient. This radiopharmaceutical is injected to the patient and its emissions are measured by a PET scanner. A PET scanner consists of an array of detectors that surround the patient. Using the gamma ray signals given off by the injected radionuclide, PET measures the amount of metabolic activity at a site in the body and a computer reassembles the signals into images. PET\'s ability to measure metabolism is very useful in diagnosing Altsheimer\'s disease, Parkinson\'s disease, epilepsy and other neurological conditions, because it can precisely illustrate areas where brain activity differs from the norm. It is also one of the most accurate methods available to localize areas of the brain causing epileptic seizures and to determine if surgery is a treatment option. PET is often used in conjunction with an MRI or CT scan through \"fusion\" to give a full three-dimensional view of an organ. ## Electromagnetic Recording Methods The methods we have mentioned up to now examine the metabolic activity of the brain. But there are also other cases in which one wants to measure electrical activity of the brain or the magnetic fields produced by the electrical activity. The methods we discussed so far do a great job of identifying where activity is occurring in the brain. A disadvantage of these methods is that they do not measure brain activity on a millisecond-by-millisecond basis. This measuring can be done by electromagnetic recording methods, for example by single-cell recording or the Electroencephalography (EEG). These methods measure the brain activity really fast and over a longer period of time so that they can give a really good temporal resolution. ### Single cell When using the single-cell method an electrode is placed into a cell of the brain on which we want to focus our attention. Now, it is possible for the experimenter to record the electrical output of the cell that is contacted by the exposed electrode tip. That is useful for studying the underlying ion currents which are responsible for the cell's resting potential. The researchers' goal is then to determine for example, if the cell responds to sensory information from only specific details of the world or from many stimuli. So we could determine whether the cell is sensitive to input in only one sensory modality or is multimodal in sensitivity. One can also find out which properties of a stimulus make cells in those regions fire. Furthermore we can find out if the animal's attention towards a certain stimulus influences in the cell's respond. Single cell studies are not very helpful for studying the human brain, since it is too invasive to be a common method. Hence, this method is most often used in animals. There are just a few cases in which the single-cell recording is also applied in humans. People with epilepsy sometimes get removed the epileptic tissue. A week before surgery electrodes are implanted into the brain or get placed on the surface of the brain during the surgery to better isolate the source of seizure activity. So using this method one can decrease the possibility that useful tissues will be removed. Due to the limitations of this method in humans there are other methods which measure electrical activity. Those we are going to discuss next. ### EEG !Placement of electrodes{width="400"} !EEG record during sleep{width="250"} One of the most famous techniques to study brain activity is probably the Electroencephalography (EEG). Most people might know it as a technique which is used clinically to detect aberrant activity such as epilepsy and disorders. Electroencephalogram (Electroencephalography, EEG) is obtained by electro-electron electroencephalography, which collects weak creatures produced by the human brain from the scalp and enlarges notes. Measuring electroencephalogram, and EEG measures, voltage fluctuations generated by the flow of ionic neurons in the brain. EEG is a diagnosis of a brain-related disease, but because it is susceptible to interference, it is usually used in combination with other methods. EEG is most commonly used to diagnose epilepsy because epilepsy can cause abnormal EEG readings. It is also used to diagnose sleep disorders, coma, cerebrovascular disease, etc., and brain death. Brain waves have been used in first-line methods to diagnose tumors, strokes, and other focal brain diseases, but this has been reduced with the advent of high-resolution anatomical imaging techniques, such as nuclear magnetic resonance (MRI). And computed tomography (CT). Unlike CT and MRI, EEGs have a higher temporal resolution. Therefore, although spatial resolution of EEG is limited, it is still a valuable tool for research and diagnostics, especially when determining studies that require time resolution in the millisecond range +----------------------+----------------------+----------------------+ \| Name \| Frequency (Hz) \| About \| +======================+======================+======================+ \| - Delta（δ） \| - 0.1\~3 Hz \| - Deep sleep and \| \| - Theta（θ） \| - 4\~7Hz \| no dreams \| \| - Alpha（α） \| - 8\~12Hz \| - When adults are \| \| - Beta（β）Low \| - 12.5 \~ 16 Hz \| under stress, \| \| Range \| - 16.5 \~ 20 Hz \| especially \| \| - Beta（β) Middle \| - 20.5 \~ 28 Hz \| disappointment \| \| Range \| - 25 \~ 100 \| or frustration \| \| - Beta（β) High \| Hz（normally \| - Relax, calm, \| \| Range \| 40Hz） \| close your eyes, \| \| - Gamma（γ） \| - according to the \| but when you are \| \| - Lambda（λ） \| power generated \| awake \| \| - P300 \| - according to the \| - Relax but \| \| \| power generated \| concentrate \| \| \| \| - Thinking, \| \| \| \| dealing with \| \| \| \| receiving \| \| \| \| external \| \| \| \| messages \| \| \| \| (hearing or \| \| \| \| thinking) \| \| \| \| - Excitement, \| \| \| \| anxiety \| \| \| \| - Raise awareness, \| \| \| \| happiness, \| \| \| \| stress \| \| \| \| reduction, \| \| \| \| meditation \| \| \| \| - Induced by 100ms \| \| \| \| after the eye is \| \| \| \| stimulated by \| \| \| \| light (also \| \| \| \| known as P100) \| \| \| \| - Induced after \| \| \| \| seeing or \| \| \| \| hearing \| \| \| \| something \| \| \| \| imagined in the \| \| \| \| brain 300ms \| \| \| \| later \| +----------------------+----------------------+----------------------+ In an experimental way this technique is used to show the brain activity in certain psychological states, such as alertness or drowsiness. To measure the brain activity mental electrodes are placed on the scalp. Each electrode, also known as lead, makes a recording of its own. Next, a reference is needed which provides a baseline, to compare this value with each of the recording electrodes. This electrode must not cover muscles because its contractions are induced by electrical signals. Usually it is placed at the "mastoid bone" which is located behind the ear. During the EEG electrodes are places like this. Over the right hemisphere electrodes are labelled with even numbers. Odd numbers are used for those on the left hemisphere. Those on the midline are labelled with a z. The capital letters stands for the location of the electrode(C=central, F=frontal, Fop= frontal pole, O= occipital, P= parietal and T= temporal). After placing each electrode at the right position, the electrical potential can be measured. This electrical potential has a particular voltage and furthermore a particular frequency. Accordingly, to a person's state the frequency and form of the EEG signal can differ. If a person is awake, beta activity can be recognized, which means that the frequency is relatively fast. Just before someone falls asleep one can observe alpha activity, which has a slower frequency. The slowest frequencies are called delta activity, which occur during sleep. Patients who suffer epilepsy show an increase of the amplitude of firing that can be observed on the EEG record. In addition EEG can also be used to help answering experimental questions. In the case of emotion for example, one can see that there is a greater alpha suppression over the right frontal areas than over the left ones, in the case of depression. One can conclude from this, that depression is accompanied by greater activation of right frontal regions than of left frontal regions. The disadvantage of EEG is that the electric conductivity, and therefore the measured electrical potentials vary widely from person to person and, also during time. This is because all tissues (brain matter, blood, bones etc.) have other conductivities for electrical signals. That is why it is sometimes not clear from which exact brain-region the electrical signal comes from. ### ERP Whereas EEG recordings provide a continuous measure of brain activity, event-related potentials (ERPs) are recordings which are linked to the occurrence of an event. A presentation of a stimulus for example would be such an event. When a stimulus is presented, the electrodes, which are placed on a person's scalp, record changes in the brain generated by the thousands of neurons under the electrodes. By measuring the brain\'s response to an event we can learn how different types of information are processed. Representing the word eats or bake for example causes a positive potential at about 200msec. From this one can conclude, that our brain processes these words 200 ms after presenting it. This positive potential is followed by a negative one at about 400ms. This one is also called N400 (whereas N stands for negative and 400 for the time). So in general one can say that there is a letter P or N to denote whether the deflection of the electrical signal is positive or negative. And a number, which represent, on average, how many hundreds of milliseconds after stimulus presentation the component appears. The event-related- potential shows special interest for researchers, because different components of the response indicate different aspects of cognitive processing. For example, presenting the sentences "The cats won't eat" and "The cat won't bake", the N400 response for the word "eat" is smaller than for the word "bake". From this one can draw the conclusion that our brain needs 400 ms to register information about a word's meaning. Furthermore, one can figure out where this activity occurs in the brain, namely if one looks at the position on the scalp of the electrodes that pick up the largest response. ### MEG Magnetoencephalography (MEG) is related to electroencephalography (EEG). However, instead of recording electrical potentials on the scalp, it uses magnetic potentials near the scalp to index brain activity. To locate a dipole, the magnetic field can be used, because the dipole shows excellently the intensity of the magnetic field. By using devices called SQUIDs (superconducting quantum interference device) one can record these magnetic fields. MEG is mainly used to localize the source of epileptic activity and to locate primary sensory cortices. This is helpful because by locating them they can be avoided during neurological intervention. Furthermore, MEG can be used to understand more about the neurophysiology underlying psychiatric disorders such as schizophrenia. In addition, MEG can also be used to examine a variety of cognitive processes, such as language, object recognition and spatial processing among others, in people who are neurologically intact. MEG has some advantages over EEG. First, magnetic fields are less influenced than electrical currents by conduction through brain tissues, cerebral spinal fluid, the skull and scalp. Second, the strength of the magnetic field can tell us information about how deep within the brain the source is located. However, MEG also has some disadvantages. The magnetic field in the brain is about 100 million times smaller than that of the earth. Due to this, shielded rooms, made out of aluminum, are required. This makes MEG more expensive. Another disadvantage is that MEG cannot detect activity of cells with certain orientations within the brain. For example, magnetic fields created by cells with long axes radial to the surface will be invisible. ## Techniques for Modulating Brain Activity ### TMS History: Transcranial magnetic stimulation (TMS) is an important technique for modulating brain activity. The first modern TMS device was developed by Antony Baker in the year 1985 in Sheffield after 8 years of research. The field has developed rapidly since then with many researchers using TMS in order to study a variety of brain functions. Today, researchers also try to develop clinical applications of TMS, because there are long lasting effects on the brain activity it has been considered as a possible alternative to antidepressant medication. Method: UMTS utilizes the principle of electromagnetic induction to an isolated brain region. A wire-coil electromagnet is held upon the fixed head of the subject. When inducing small, localized, and reversible changes in the living brain tissue, especially the directly under laying parts of the motor cortex can be effected. By altering the firing-patterns of the neurons, the influenced brain area is disabled. The repetitive TMS (rTMS) describes, as the name reveals, the application of many short electrical stimulations with a high frequency and is more common than TMS. The effects of this procedure last up to weeks and the method is in most cases used in combination with measuring methods, for example: to study the effects in detail. Application: The TMS-method gives more evidence about the functionality of certain brain areas than measuring methods on their own. It was a very helpful method in mapping the motor cortex. For example: While rTMS is applied to the prefrontal cortex, the patient is not able to build up short term memory. That determines the prefrontal cortex, to be directly involved in the process of short term memory. By contrast measuring methods on their own, can only investigate a correlation between the processes. Since even earlier researches were aware that TMS could cause suppression of visual perception, speech arrest, and paraesthesias, TMS has been used to map specific brain functions in areas other than motor cortex. Several groups have applied TMS to the study of visual information processing, language production, memory, attention, reaction time and even more subtle brain functions such as mood and emotion. Yet long time effects of TMS on the brain have not been investigated properly, Therefore experiments are not yet made in deeper brain regions like the hypothalamus or the hippocampus on humans. Although the potential utility of TMS as a treatment tool in various neuropsychiatric disorders is rapidly increasing, its use in depression is the most extensively studied clinical applications to date. For instance in the year 1994, George and Wassermann hypothesized that intermittent stimulation of important prefrontal cortical brain regions might also cause downstream changes in neuronal function that would result in an antidepressant response. Here again, the methods effects are not clear enough to use it in clinical treatments today. Although it is too early at this point to tell whether TMS has long lasting therapeutic effects, this tool has clearly opened up new hopes for clinical exploration and treatment of various psychiatric conditions. Further work in understanding normal mental phenomena and how TMS affects these areas appears to be crucial for advancement. A critically important area that will ultimately guide clinical parameters is to combine TMS with functional imaging to directly monitor TMS effects on the brain. Since it appears that TMS at different frequencies has divergent effects on brain activity, TMS with functional brain imaging will be helpful to better delineate not only the behavioral neuropsychology of various psychiatric syndromes, but also some of the pathophysiologic circuits in the brain. ### tDCS transcranial Direct Current Stimulation: The principle of tDCS is similar to the technique of TMS. Like TMS this is a non-invasive and painless method of stimulation. The excitability of brain regions is modulated by the application of a weak electrical current. History and development: It was first observed that electrical current applied to the skull lead to an alleviation of pain. Scribonius Largus, the court physician to the Roman emperor Claudius, found that the current released by the electric ray has positive effects on headaches. In the Middle Ages the same property of another fish, the electrical catfish, was used to treat epilepsy. Around 1800, the so-called galvanism (it was concerned with effects of today's electrophysiology) came up. Scientists like Giovanni Aldini experimented with electrical effects on the brain. A medical application of his findings was the treatment of melancholy. During the twentieth century among neurologists and psychiatrists electrical stimulation was a controversial but nevertheless wide spread method for the treatment of several kinds of mental disorders (e.g. Electroconvulsive therapy by Ugo Cerletti). Mechanism: The tDCS works by fixation of two electrodes on the skull. About 50 percent of the direct current applied to the skull reaches the brain. The current applied by a direct current battery usually is around 1 to 2 mA. The modulation of activity of the brain regions is dependent on the value of current, on the duration of stimulation and on the direction of current flow. While the former two mainly have an effect on the strength of modulation and its permanence beyond the actual stimulation, the latter differentiates the modulation itself. The direction of the current (anodic or cathodic) is defined by the polarity and position of the electrodes. Within tDCS two distinct ways of stimulation exist. With the anodal stimulation the anode is put near the brain region to be stimulated and analogue for the cathodal stimulation the cathode is placed near the target region. The effect of the anodal stimulation is that the positive charge leads to depolarization in the membrane potential of the applied brain regions, whereas hyperpolarisation occurs in the case of cathodal stimulation due to the negative charge applied. The brain activity thereby is modulated. Anodal stimulation leads to a generally higher activity in the stimulated brain region. This result can also be verified with MRI scans, where an increased blood flow in the target region indicates a successful anodal stimulation. Applications: From the description of the TMS method it is should be obvious that there are various fields of appliances. They reach from identifying and pulling together brain regions with cognitive functions to the treatment of mental disorders. Compared to TMS it is an advantage of tDCS to not only is able to modulate brain activity by decreasing it but also to have the possibility to increase the activity of a target brain region. Therefore the method could provide an even better suitable treatment of mental disorders such as depression. The tDCS method has also already proven helpful for apoplectic stroke patients by advancing the motor skills. ## Behavioural Methods Besides using methods to measure the brain's physiology and anatomy, it is also important to have techniques for analyzing behaviour in order to get a better insight on cognition. Compared to the neuroscientific methods, which concentrate on neuronal activity of the brain regions, behavioural methods focus on overt behaviour of a test person. This can be realized by well defined behavioural methods (e.g. eye-tracking), test batteries (e.g. IQ-test) or measurements which are designed to answer specific questions concerning the behaviour of humans. Furthermore, behavioural methods are often used in combination with all kinds of neuroscientific methods mentioned above. Whenever there is an overt reaction on a stimulus (e.g. picture) these behavioural methods can be useful. Another goal of a behavioural test is to examine in what terms damage of the central nervous system influences cognitive abilities. ### A Concept of a behavioural test The tests are performed to give an answer to certain questions about human behaviour. In order to find an answer to that question, a test strategy has to be developed. First it has to be carefully considered, how to design the test in the best way, so that the measurement results provide an accurate answer to the initial question. How can the test be conducted so that founding variables are minimal and the focus really is on the problem? When an appropriate test arrangement is found, the defining of test variables is the next part. The test is now conducted and probably repeated until a sufficient amount of data is collected. The next step is the evaluation of the resulting data, with the suitable methods of statistics. If the test reveals a significant result, it might be the case that further questions arise about neuronal activity underlying the behaviour. Then neuroscientific methods are useful to investigate correlating brain activities. Methods, which proved to provide good evidence to a certain recurrent question about cognitive abilities of subjects, can bring together in a test battery. Example: Question: Does a noisy surrounding affect the ability to solve a certain problem? Possible test design: Expose half of the subject to a silent environment while solving the same task as the other half in a noisy environment. In this example founding variables might be different cognitive abilities of the participants. Test variables could be the time needed to solve the problem and the loudness of the noise etc. If statistical evaluation shows significance: Probable further questions: How does noise affect the brain activities on a neuronal level? Are you interested in doing a behavioural test on your own, visit: the socialpsychology.org website.[^2] ### Test batteries A neuropsychological assessment utilizes test batteries that give an overview on a person's cognitive strengths and weaknesses by analyzing various cognitive abilities. A neuropsychological test battery is used by a neuropsychologist to assess brain dysfunctions that can rise from developmental, neurological or psychiatric issues. Such batteries can appraise various mental functions and the overall intelligence of a person. Firstly, there are test batteries designed to assess whether a person suffers from a brain damage or not. They generally work well in discriminating those with brain damage from neurologically impaired patients, but worse when it comes to discriminating them from those with psychiatric disorders. The most popular test, Halstead-Reitan battery, assesses abilities ranging from basic sensory processing to complex reasoning. Furthermore, the Halstead-Reitan battery provides information on the cause of the damage, the brain areas that were harmed, and the stage the damage has reached. Such information is valuable in developing a rehabilitation program. Another test battery, the Luria-Nebraska battery, is twice as fast to administer as the Halstead-Reitan. Its subtests are ordered according to twelve content scales (e.g. motor functions, reading, memory etc.). These two test batteries do not focus only on the absolute level of performance, but look at the qualitative manner of performance as well. This allows for a more comprehensive understanding of the cognitive impairment. Another type of test batteries, the so-called IQ tests, aims to measure the overall cognitive performance of an individual. The most commonly used tests for estimating intelligence are the Wechsler family intelligence tests. Age-appropriate test versions exist for small children from age 2 years and 6 months, school-aged children, and adults. For example, the Wechsler Intelligence Scale for Children, fifth edition (WISC-V) measures various cognitive abilities in children between 6 and 16 years of age. The test consists of multiple subtests that form five different main indexes of cognitive performance. These main constructs are verbal reasoning skills, inductive reasoning skills, visuo-spatial processing, processing speed and working memory. Performance is analyzed both compared to a normative sample of similarly aged peers and within the test subject, assessing personal strengths and weaknesses. ### The Eye Tracking Procedure Another important procedure for analyzing behavior and cognition is Eye-tracking. This is a procedure of measuring either where we are looking (the point of gaze) or the motion of an eye relative to the head. There are different techniques for measuring the movement of the eyes and the instrument that does the tracking is called the tracker. The first non-intrusive tracker was invented by George Buswell. The eye tracking is a study with a long history, starting back in the 1800s. In 1879 Louis Emile Javal noticed that reading does not involve smooth sweeping of the eye along the text but rather series of short stops which are called fixations. This observation is one of the first attempts to examine the eye's directions of interest. The book of Alfred L. Yarbus which he published in 1967 after an important eye tracking research is one of the most quoted eye tracking publications ever. The eye tracking procedure is not that complicated. Video based eye trackers are frequently used. A camera focuses on one or both eyes and records the movements while the viewer looks at some stimulus. The most modern eye trackers use contrast to locate the center of the pupil and create corneal reflections using infrared or near-infrared non-collimated light. There are also two general types of eye tracking techniques. The first one -- the Bright Pupil is an effect close to the red eye effect and it appears when the illuminator source is onset from the optical path while when the source is offset from the optical path, the pupil appears to be dark (Dark Pupil). The Bright Pupil creates great contrast between the iris and the pupil which allows tracking in light conditions from dark to very bright but it is not effective for outdoor tracking. There are also different eye tracking setup techniques. Some are head mounted, some require the head to be stable, and some automatically track the head during motion. The sampling rate of the most of them is 30 Hz. But when we have rapid eye movement, for example during reading, the tracker must run at 240, 350 or even 1000-1250 Hz in order to capture the details of the movement. Eye movements are divided to fixations and saccades. When the eye movement pauses in a certain position there is a fixation and saccade when it moves to another position. The resulting series of fixations and saccades is called a scan path. Interestingly most information from the eye is received during a fixation and not during a saccade. Fixation lasts about 200 ms during reading a text and about 350 ms during viewing of a scene and a saccade towards new goal takes about 200 ms. Scan paths are used in analyzing cognitive intent, interest and salience. Eye tracking has a wide range of application -- it is used to study a variety of cognitive processes, mostly visual perception and language processing. It is also used in human-computer interactions. It is also helpful for marketing and medical research. In recent years the eye tracking has generated a great deal of interest in the commercial sector. The commercial eye tracking studies present a target stimulus to consumers while a tracker is used to record the movement of the eye. Some of the latest applications are in the field of the automotive design. Eye tracking can analyze a driver's level of attentiveness while driving and prevent drowsiness from causing accidents. ## Modeling Brain-Behaviour Another major method, which is used in cognitive neuroscience, is the use of neural networks (computer modelling techniques) in order to simulate the action of the brain and its processes. These models help researchers to test theories of neuropsychological functioning and to derive principles viewing brain-behaviour relationships. !A basic neural network.{width="500"} In order to simulate mental functions in humans, a variety of computational models can be used. The basic component of most such models is a "unit", which one can imagine as showing neuron-like behaviour. These units receive input from other units, which are summed to produce a net input. The net input to a unit is then transformed into that unit's output, mostly utilizing a sigmoid function. These units are connected together forming layers. Most models consist of an input layer, an output layer and a "hidden" layer as you can see on the right side. The input layer simulates the taking up of information from the outside world, the output layer simulates the response of the system and the "hidden" layer is responsible for the transformations, which are necessary to perform the computation under investigation. The units of different layers are connected via connection weights, which show the degree of influence that a unit in one level has on the unit in another one. The most interesting and important about these models is that they are able to \"learn\" without being provided specific rules. This ability to "learn" can be compared to the human ability e.g. to learn the native language, because there is nobody who tells one "the rules" in order to be able to learn this one. The computational models learn by extracting the regularity of relationships with repeated exposure. This exposure occurs then via "training" in which input patterns are provided over and over again. The adjustment of "the connection weights between units" as already mentioned above is responsible for learning within the system. Learning occurs because of changes in the interrelationships between units, which occurrence is thought to be similar in the nervous system. ## References ```{=html} <references/> ``` - Ward, Jamie (2006) The Student\'s Guide to Cognitive Neuroscience New York: Psychology Press - Banich,Marie T. (2004). Cognitive Neurosciene and Neuropsychology. Housthon Mifflin Company. - Gazzangia, Michael S.(2000). Cognitive Neuroscience. Blackwell Publishers. - 27.06.07 Sparknotes.com - $1$ 4 April 2001 / Accepted: 12 July 2002 / Published: 26 June 2003 Springer-Verlag 2003. Fumiko Maeda • Alvaro Pascual-Leone. Transcranial magnetic stimulation: studying motor neurophysiology of psychiatric disorders - $2$ a report by Drs Risto J Ilmoniemi and Jari Karhu Director, BioMag Laboratory, Helsinki University Central Hospital, and Managing Director, Nexstim Ltd - $3$ Repetitive Transcranial Magnetic Stimulation as Treatment of Poststroke Depression: A Preliminary Study Ricardo E. Jorge, Robert G. Robinson, Amane Tateno, Kenji Narushima, Laura Acion, David Moser, Stephan Arndt, and Eran Chemerinski - Moates, Danny R. An Introduction to cognitive psychology. B:HRH 4229-724 0 [^1]: Filler, AG: The history, development, and impact of computed imaging in neurological diagnosis and neurosurgery: CT, MRI, DTI: Nature Precedings DOI: 10.1038/npre.2009.3267.4. [^2]: Socialpsychology.org
# Cognitive Psychology and Cognitive Neuroscience/Motivation and Emotion +:------------------------------+:----:+------------------------------:+ \| Previous \| [O \| [Next \| \| Chapter \| \| roscience_Methods "wikilink") \| niti \| \| \| \| ve_P \| \| \| \| sych \| \| \| \| olog \| \| \| \| y_an \| \| \| \| d_Co \| \| \| \| gnit \| \| \| \| ive_ \| \| \| \| Neur \| \| \| \| osci \| \| \| \| ence \| \| \| \| "wi \| \| \| \| kili \| \| \| \| nk") \| \| +-------------------------------+------+-------------------------------+ ## Introduction Happiness, sadness, anger, surprise, disgust and fear. All these words describe some kind of abstract inner states in humans, in some cases difficult to control. We usually call them feelings or emotions. But what is the reason that we are able to \"feel\"? Where do emotions come from and how are they caused? And are emotions and feelings the same thing? Or are we supposed to differentiate? These are all questions that cognitive psychology deals with in emotion research. Emotion research in the cognitive science is not much older than twenty years. The reason for this lies perhaps in the fact that much of the cognitive psychology tradition was based on computer-inspired information-processing models of cognition. This chapter gives an overview about the topic for a better understanding of motivation and emotions. It provides information about theories concerning the cause of motivation and emotions in the human brain, their processes, their role in the human body and the connection between the two topics. We will try to show the actual state of research, some examples of psychologist experiments, and different points of view in the issue of emotions. In the end we will briefly outline some disorders to emphasize the importance of emotions for the social interaction. ## Motivation ### About Drives and Motives Motivation is an extended notion, which refers to the starting, controlling and upholding of corporal and mental activities. It is declared by inner processes and variables which are used to explain behavioral changes. Motivations are commonly separated into two types: 1.Drives: describe acts of motivation like thirst or hunger that have primarily biological purposes. 2.Motives: are driven by primarily social and psychological mechanisms. Motivation is an interceding variable, which means that it is a variable that is not directly observable. Therefore, in order to study motivation, one must approach it through variables which are measurable and observable: \- Observable terms of variation (independent variables [^1]) \- Indicators of behavior (dependent variables[^2]) e.g.: rate of learning, level of activity, \... There are two major methodologies used to manipulate drives and motives in experiments: Stimulation: Initiating motives by aversive attractions like shocks, loud noise, heat or coldness. On the other side attractions can activate drives which lead to positive affective states, e.g. sexual drives. Deprivation: means that you prohibit the access to elementary aspects of biological or psychological health, like nutrition or social contacts. As a result it leads it to motives or drives which are not common for this species under normal conditions. A theory of motivations was conceived by Abraham Maslow in 1970 (Maslow\'s hierarchy of needs). He considered two kinds of motivation: 1\. Defected motivation: brings humans to reconsider their psychical and physical balance. 2\. Adolescence motivation: gets people to pass old events and states of their personal development. Maslow argues that everyone has a hierarchy of needs(see picture). Regarding to this, our innate needs could be ordered in a hierarchy, starting at the "basic" ones and heading towards higher developed aspects of humanity. The hypothesis is that the human is ruled by lower needs as long as they are not satisfied. If they are satisfied in an adequate manner, the human then deals with higher needs. (compare to chapter attention) !Hierarchy of needs, Maslow (1970)") Nevertheless, all throughout history you can find examples of people who willingly practiced deprivation through isolation, celibacy, or by hunger strike. These people may be the exceptions to this hypothesis, but they may also have some other, more pressing motives or drives which induce them to behave in this way. It seems that individuals are able to resist certain motives via personal cognitive states. The ability of cognitive reasoning and willing is a typical feature of being human and can be the reason for many psychological diseases which indicates that humans are not always capable to handle all rising mental states. Humans are able to manipulate their motives without knowing the real emotional and psychological causes. This introduces the problem that the entity of consciousness, unconsciousness and what ever else could be taken into account is essentially unknown. Neuroscience cannot yet provide a concrete explanation for the neurological substructures of motives, but there has been considerable progress in understanding the neurological procedures of drives. ### The Neurological Regulation of Drives #### The Role of the Hypothalamus The purpose of drives is to correct disturbances of homeostasis which is controlled by the hypothalamus. Deviations from the optimal range of a regulated parameter like temperature are detected by neurons concentrated in the periventricular zone of the hypothalamus. These neurons then produce an integrated response to bring the parameter back to its optimal value. This response generally consists of 1\. Humoral response 2\. Visceromotor response 3\. Somatic motor response When you are dehydrated, freezing, or exhausted, the appropriate humoral and visceromotor responses are activated automatically,[^3] e.g.: body fat reserves are mobilized, urine production is inhibited, you shiver, blood is shunted away from the body surface, ... But it is much faster and more effective to correct these disturbances by eating, drinking water or actively seeking or generating warmth by moving. These are examples of drives generated by the somatic motor system, and they are incited to emerge by the activity of the lateral hypothalamus. For illustration we will make a brief overview on the neural basis of the regulation of feeding behavior, which is divided into the long-term and the short-term regulation of feeding behavior. The long-term regulation of feeding behavior prevents energy shortfalls and concerns the regulation of body fat and feeding. In the 1940s the "dual center" model was popular, which divided the hypothalamus in a "hunger center" (lateral hypothalamus) and a "satiety center" (ventromedial hypothalamus). This theory developed from the facts that bilateral lesions of the lateral hypothalamus causes anorexia, a severely diminished appetite for food (lateral hypothalamic syndrome) and on the other side bilateral lesions of the ventromedial hypothalamus causes overeating and obesity (ventromedial hypothalamic syndrome). Anyway, it has been proved that this "dual model" is overly simplistic. The reason why hypothalamic lesions affect body fat and feeding behavior has in fact much to do with leptin signaling. Adipocytes (fat cells) release the hormone leptin, which regulates body mass by acting directly on neurons of the arcuate nucleus[^4] of the hypothalamus that decreases appetite and increase energy expenditure. A fall in leptin levels stimulates another type of arcuate nucleus neurons[^5] and neurons in the lateral hypothalamus,[^6] which activate the parasympathetic division of the ANS, and stimulate feeding behavior. The short-term regulation of feeding behavior deals with appetite and satiety. Until 1999 scientists believed that hunger was merely the absence of satiety. This changed with the discovery of a peptide called ghrelin, which is highly concentrated in the stomach and is released into the bloodstream when the stomach is empty. In the arcuate nucleus it activates neurons,[^7] that strongly stimulate appetite and food consumption. The meal finally ends by the concerted actions of several satiety signals, like gastric distension and the release of insulin.[^8] But it seems that animals not only eat because they want food to satisfy their hunger. They also eat because they like food in a merely hedonistic sense. Research on humans and animals suggests that "liking" and "wanting" are mediated by separate circuits in the brain. #### The Role of Dopamine in Motivation In the early 1950s, Peter Milner and James Olds conducted an experiment in which a rat had an electrode implanted in its brain, so the brain could be locally stimulated at any time. The rat was seated in a box, which contained a lever for food and water and a lever that would deliver a brief stimulus to the brain when stepped on. At the beginning the rat wandered about the box and stepped on the levers by accident, but before long it was pressing the lever for the brief stimulus repeatedly. This behavior is called electrical self-stimulation. Sometimes the rats would become so involved in pressing the lever that they would forget about food and water, stopping only after collapsing from exhaustion. Electrical self-stimulation apparently provided a reward that reinforced the habit to press the lever. Researches were able to identify the most effective sites for self-stimulation in the different regions of the brain: the mesocorticolimbic dopamine system. Drugs that block dopamine receptors reduced the self-stimulation behavior of the rat. In the same way this drugs greatly reduced the pressing of a lever for receiving of food even if the rat was hungry. These experiments suggested a mechanism by which natural rewards (food, water, sex) reinforce particular behavior. Dopamine plays an important role in addiction of drugs like heroin, nicotine and cocaine. Thus these drugs either stimulate dopamine release (heroin, nicotine) or enhance dopamine actions (cocaine) in the nucleus accumbens. Chronic stimulation of this pathway causes a down-regulated of the dopamine "reward" system. This adaption leads to the phenomenon of drug tolerance. Indeed, drug discontinuation in addicted animals is accompanied by a marked decrease in dopamine release and function in the nucleus accumbens, leading to the symptom of craving for the discontinued drug. The exact role of dopamine in motivating behavior continues to be debated. However, much evidence suggests that animals are motivated to perform behaviors that stimulate dopamine release in the nucleus accumbens and related structures ## Emotions ### Basics In contrast to previous research, modern brain based neuroscience has taken a more serviceable approach to the field of Emotions, because emotions definitely are brain related processes which deserve scientific study, whatever their purpose may be. One interpretation regards emotions as „action schemes", which especially lead to a certain behaviour which is essential for survival. It is important to distinguish between conscious aspects of emotion like subjective - often bodily - feelings, as well as unconscious aspects like the detection of a threat. This will be discussed later on in conjunction with awareness of emotion. It is also important to differentiate between a mood and an emotion. A mood refers to a situation where an emotion occurs frequently or continuously. As an example: Fear is an emotion, anxiety is a mood. The first question which arises is how to categorise emotions. They could be treated as a single entity, but perhaps it could even make more sense to distinguish between them, which leads to the question if some emotions like happiness or anger are more basic than other types like jealousy or love and if emotions are dependent on culture and/or language. One of the most influential ethnographic studies by Eckman and Friesen, which is based on the comparison of facial expressions of emotions in different cultures, concluded that there are six basic types of emotions expressed in faces - namely sadness, happiness, disgust, surprise, anger and fear, independent from culture and language. An alternative approach is to differentiate between emotions not by categorising but rather by measuring the intensity of an emotion by imposing different dimensions, e.g. their valence and their arousal. If this theory would be true then one might expect to find different brain regions which selectivey process positive or negative emotions. !Six basic types of emotions expressed in faces{width="500"} Complex emotions like jealousy, love and pride are different from basic emotions as they comprehend awareness of oneself in relation to other people and one\'s attitude towards other people. Hence they come along with a more complex attributional process which is required to appreciate thoughts and beliefs of other people. Complex emotions are more likely be dependent on cultural influences than basic types of emotions. If you think of Knut who is feeling embarrassment, you have to consider what kind of action he committed in which situation and how this action raised the disapproval of other people. ### Awareness and Emotion Awareness is closely connected with changes in the environment or in the psycho-physiological state. Why recognise changes rather than stable states? An answer could be that changes are an important indicator of our situation. They show that our situation is unstable. Paying attention or focusing on that might increase the chance to survive. A change bears more information than repetitive events. This appears more exciting. Repetition reduces excitement. If we think that we got the most important information from a situation or an event,we become unaware of such an event or certain facts. Current research in this field suggest that changes are needed to emerge emotions,so we can say that it is strong attention dependent. The event has to draw our attention. No recognition, no emotions. But do we have always an emotional evaluation, when we are aware of certain events? How has the change to be relevant for our recognition? Emotional changes are highly personal significant, saying that it needs a relation to our personal self. Significance presupposes order and relations. Relations are to meaning as colours are to vision: a necessary condition, but not its whole content. One determines the significance and the scope of a change by f.e. event´s impact (event´s strength), reality, relevance and factors related to the background circumstances of the subject. We feel no emotion in response to change which we perceive as unimportant or unrelated. Roughly one can say that emotions express our attitude toward unstable significant objects which are somehow related to us. This is also always connected with the fact that we have greater response to novel experience. Something that is unexpected or unseen yet. When children get new toys, they are very excited at first, but after a while one can perceive, or simply remember their own childhood, that they show less interest in that toy. That shows, that emotional response declines during time. This aspect is called the process of adaptation. The threshold of awareness keeps rising if stimulus level is constant. Hence, awareness decreases. The organism withdraws its consciousness from more and more events. The person has the pip, it has enough. The opposite effect is also possible. It is known as the process of facilitation. In this case the threshold of awareness diminishes. Consciousness is focusing on increasing number of events. This happens if new stimuli are encountered. The process of adaptation might prevent us from endlessly repetitive actions. A human would not be able to learn something new or be caught in an infinite loop. The emotional environment contains not only what is, and what will be, experienced but also all that could be, or that one desires to be, experienced; for the emotional system, all such possibilities are posited as simultaneously there and are compared with each other. Whereas intellectual thinking expresses a detached and objective manner of comparison, the emotional comparison is done from a personal and interested perspective; intellectual thinking may be characterised as an attempt to overcome the personal emotional perspective. It is quite difficult to give an external description of something that is related to an intrinsic, personal perspective. But it is possible. In the following the most popular theories will be shown, and an rough overview about the neural substrates of emotions. ### The Neural Correlate of Emotion #### Papez Circuit James W. Papez was the investigator of the Papez Circuit theory (1937). He was the first who tried to explain emotions in a neurofuncional way. Papez discovered the circuit after injecting the baring-virus into a cat\'s hippocampus andobserved its effects on the brain. The Papez circuit is chiefly involved in the cortical control of emotion. The corpus mamillare (part of the hypothalamus) plays a central role. The Papez Circuit involves several regions in the brain with the following course: ● The hippocampus projects to fornix and via this to corpus mamillare ● from here neurons project via the fasciculus mamillothalamicus to nucleus anterior of the thalamus and then to the gyrus cinguli ● due to the connection of gyrus cinguli and hippocampus the circuit is closed. 1949 Paul MacLean extended this theory by hypothezing that regions like the amygdala and the orbitofrontal cortex work together with the circuit and form an emotional brain. However, the theory of the Papez circuit could no longer be held because, for one, some regions of the circuit can no longer be related to functions to which they were ascribed primarily. And secondly, current state of research concludes that each basic emotion has its own circuit. Furthermore, the assumption that the limbic system is solely responsible for these functions is out-dated. Other cortical and non-cortical structures of the brain have an enormous bearing on the limbic system. So the emergence of emotion is always an interaction of many parts of the brain. #### Amygdala and Fear The Amygdala (lat. Almond), latinic-anatomic Corpus amygdaloideum, is located in the left and right temporal lobe. It belongs to the limbic system and is essentially involved in the emergence of fear. In addition, the amygdala plays a decisive role in the emotional evaluation and recognition of situations as well as in the analysis of potential threat. It handles external stimuli and induces vegetative reactions. These may help prepare the body for fight and flight by increasing heart and breathing-rate. The small mass of grey matter is also responsible for learning on the basis of reward or punishment. If the two parts of the amygdala are destroyed the person loses their sensation of fear and anger. Experiments with patients whose amygdala is damaged show the following: The participants were impaired to a lesser degree with recognizing facial anger and disgust. They could not match pictures of the same person when the expressions were different. Beyond Winston, O´Doherty and Dolan report that the amygdala activation was independent of whether or not subjects engaged in incidental viewing or explicit emotion judgements. However, other regions (including the ventromedial frontal lobes) were activated only when making explicit judgements about the emotion. This was interpreted as reinstatement of the „feeling" of the emotion. Further studies show that there is a slow route to the amygdala via the primary visual cortex and a fast subcortical route from the thalamus to the amygdala. The amygdala is activated by unconscious fearful expressions in healthy participants and also „blindsight" patients with damage to primary visual cortex. The fast route is imprecise and induces fast unconscious reactions towards a threat before you consciously notice and may properly react via the slow route. This was shown by experiments with persons who have a snake phobia (ophidiophobics) or a spider phobia (arachnophobics). When they get to see a snake, the former showed a bodily reaction, before they reported seeing the snake. A similar reaction was not observable in the case of a spiderphobia. By experiments with spiders the results were the other way round. #### Recognition of Other Emotional Categories Another basic emotional category which is largely independent of other emotions is disgust. It literally means „bad taste" and is evolutionary related to contamination through ingestion. Patients with the Huntington\'s disease have problems with recognizing disgust. The insula, a small region of cortex buried beneath the temporal lobes, plays an important role for facial expressions of disgust. Furthermore, the half of the patients with a damaged amygdala have problems with facial expressions of sadness. The damage of the ventral regions of the basal ganglia causes the deficit in the selective perception of anger and this brain area could be responsible for the perception of aggression. Happiness cannot be selectively impaired because it consist of a more distributed network. ### Functional Theories In order to explain human emotions, that means to discover how they arise and investigate how they are represented in the brain, researchers worked out several theories. In the following the most important views will be discussed #### James -- Lange Theory The James -- Lange theory of emotion states that the self -- perception of bodily changes produces emotional experience. For example you are happy because you are laughing or you feel sad because you are crying. Alternatively, when a person sees a spider he or she might experience fear. One problem according this theory is that it is not clear what kind of processing leads to the changes in the bodily state and wether this process can be seen as a part of the emotion itself. However, people paralyzed from the neck down, who have little awareness of sensory input are still able to experience emotions. Also, research by Schacter and Singer has shown, that changes in bodily state are not enough to produce emotions. Because of that, an extension of this theory was necessary. #### Two Factor Theory The two factor theory views emotion as an compound of the two factors: physiological arousal and cognition. Schacter and Singer (1962) did well-known studies in this field of research. They injected participants with adrenaline (called epinephrine in the USA). This is a drug that causes a number of effects like increased blood flow to the muscles and increased heart rate. The result was that the existence of the drug in the body did not lead to experiences of emotion. Just with the presence of an cognitive setting, like an angry man in the room, participants did self -- report an emotion. Contrary to the James -- Lange theory this study suggests that bodily changes can only support conscious emotional experiences but do not create emotions. Therefore, the interpretation of a certain emotion depends on the physiological state in correlation to the subjects circumstances. #### Somatic Marker Hypothesis This current theory of emotions (from A. Damasio) emphasizes the role of bodily states and implies that "somatic marker" signals have influence on behaviour, like particularly reasoning and decision--making. Somatic markers are the connections between previous situations, which are stored in the cortex, and the bodily feeling of such situations (e.g. stored in the amygdala). From this it follows, that the somatic markers are very useful during the decision process, because they can give you immediate response on the grounds of previous acquired knowledge, whether the one or the other option "feels" better. People who are cheating and murdering without feeling anything miss somatic markers which would prevent them from doing this. In order to investigate this hypothesis a gambling task was necessary. There have been four decks of cards (A, B, C, D) on the table and the participants had to take always one in turn. On the other side of the card was either a monetary penalty or gain. The players have been told that they must play so that they win the most. Playing from decks A and B leads to a loss of money whereas choosing decks C and D leads to gain. Persons without a brain lesion learned to avoid deck A and B but players with such damage did not. ### Reading Minds Empathy is the ability to appreciate others' emotions and their point of view. Simulation theory states that the same neural and cognitive resources are used by perceiving the emotional expressions of others and by producing actions and this expressions in oneself. If you are watching a movie where one person touches another, the same neural mechanism (in the somatosensory cortex) is activated as if you were physically touched. Further studies investigated empathy for pain. That means, if you see someone experiencing pain, two regions in your brain are overlapping. The first region is responsible for expecting another person's pain, and the second region is responsible for experiencing this pain oneself. ### Mood and Memory While we store a memory, we not only record all sensory data, we also store our mood and emotional state. Our current mood thus will affect the memories that are most effortlessly available to us, such that when we are in a good mood we recollect good memories (and vice versa). While the nature of memory is associative this also means that we tend to store happy memories in a linked set. There are two different ways we remember past events: #### Mood-congruence Memory occurs where current mood helps recall of mood-congruent material, e.g. characters in stories that feel like the reader feels while reading, regardless of our mood at the time the material was stored. Thus when we are happy, we are more likely to remember happy events. Also remembering all of the negative events of our past when depressed is an example of mood congruence. That means that you can rather remember a funeral where you were happy in a happy mood while you remember a party where you were sad in a sad mood, although a funeral is sad and a party is happy. #### Mood-dependency Memory occurs where the congruence of current mood with the mood at the time of memory storage helps recall of that memory. When we are happy, we are more likely to remember other times when we were happy. So, if you want to remember something, get into the mood you were in when you experienced it. You can easily try this yourself. You just have to bring into a certain mood by listening to the saddest/happiest music you know. Now you learn a list of words. Then you try to recall the list in the other/the same mood. You will see that you remember the list better when you are in the same mood as you were while learning it. ## Disorders Without balanced emotions, one\'s ability to interact in a social network will be affected in some manner (e.g. reading minds). In this part of the chapter some grave disorders will be presented- these are: depression, austism and antisocial behaviour disorders as psychopathy and sociopathy. It is important to mention that those disorders will mainly be considered in regard to their impact on social competence. To get a full account of the characteristics of each of the disorders, we recommend reading the particular articles provided by Wikipedia. ### Autism Autism is thought to be an innate condition with individual forms distributed on a broad spectrum. This means that symptoms can range from minor behavioral problems to major mental deficits, but there is always some impairment of social competence. The American Psychiatric Association characterizes autism as \"the presence of markedly abnormal or impaired development in social interaction and communication and a markedly restricted repertoire of activities and interests\" (1994, diagnostic and statistical manual; DSM-IV). The deficits in social competence are sometimes divided into the so-called \"triad of impairments\", including: (1)Social interaction This includes difficulties with social relationships, for example appearing distanced and indifferent to other people. (2)Social communication Autists have problems with verbal and non-verbal communication, for example, they do not fully understand the meaning of common gestures, facial expressions or the voice tones. They often show reduced or even no eye-contact as well, avoid body contact like shaking hands and have difficulties to understand metaphores and \"to read between the lines\". (3)Social imagination Autists lack social imagination manifesting in difficulties in the development of interpersonal play and imagination, for example having a limited range of imaginative activities, possibly copied and pursued rigidly and repetitively. All forms of autism can already be recognized during childhood and therefore disturb the proper socialization of the afflicted child. Often autistic children are less interested in playing with other children but for example love to arrange their toys with utmost care. Unable to interpret emotional expressions and social rules autists are prone to show inappropriate behaviour towards the people surrounding them. Autists may not obviously be impaired therefore other people misunderstand their actions as provocation. Still there are other features of autism- autists often show stereotyped behaviour and feel quite uncomfortable when things change in the routines and environment they are used to. Very rarely, a person with autism may have a remarkable talent, such as memorizing a whole city panorama including, for example, the exact number of windows in each of the buildings. There are several theories trying to explain autism or features of autism. In an experiment conducted by Baron-Cohen and colleagues (1995) cartoons were presented to normal and autistic children showing a smiley in the centre of each picture and four different sweets in each corner (see picture below). The smiley, named Charlie, was gazing at one of the sweets. The children were asked question as: \"Which chocolate does Charlie want?\" !Autistic children were able to detect where the smiley was looking but unable to infer its \'desires\'. (adapted graphic from Ward, J. (2006). The Students Guide to Cognitive Neuroscience. Hove: Psychology Press. page 316). The Students Guide to Cognitive Neuroscience. Hove: Psychology Press. page 316)") Normal children could easily infer Charlie\'s desires from Charlie\'s gaze direction whereas autistic children would not guess the answer. Additional evidence from other experiments suggest that autists are unable to use eye gaze information to interpret people\'s desires and predict their behaviour which would be crucial for social interaction. Another proposal to explain autistic characteristics suggests that autists lack representations of other people\'s mental states (mindblindness - proposed by Baron-Cohen, 1995b). ### Depression Depression is a disorder that leads to an emotional disfunction characterized by a state of intensive sadness, melancholia and despair. The disorder affects social and everyday life. There are many different forms of depression that differ in strength and duration. People affected by depression suffer from anxiety, distorted thinking, dramatic mood changes and many other symptoms. They feel sad, and everything seems to be bleak. This leads to an extremely negative view of themselves and their current and future situation. These factors can lead to a loss of a normal social life that might affect the depressed person even further. Suffering from depression and losing your social network can thereby lead to a vicious circle. ### Psychopathy and Sociopathy Psychopathy and sociopathy are nowadays subsumed under the notion of antisocial behaviour disorders but experts are still quite discordant whether both are really separated disturbances or rather forms of other personal disorders e.g. autism. Psychopaths and sociopaths often get into conflict with their social environment because they repeatedly violate social and moral rules. Acquired sociopathy manifests in the inability to form lasting relationships, irresponsible behaviour as well as getting angry quite fast and exceptional strong egocentric thinking. While acquired sociopathy might be characterised by impulsive antisocial behaviour often having no personal advantage, developmental psychopathy manifests in goal directed and self-initiated aggression. Acquired sociopathy is caused by brain injury especially found in the orbitofrontal lobe (frontal lobe) and is thought to be a failure to use emotional cues and the loss of social knowledge. Therefore sociopaths are unable to control and plan their behaviour in a socially adequate manner. In contrast to sociopaths psychopaths are not getting angry because of minor reasons but they act aggressively without understandable reasons at all which might be due to their inability to understand and distinguish between moral rules (concerning the welfare of others) and conventions (consensus rules of society). Furthermore it even happens that they feel no guilt or empathy for their victims. Psychopathy is probably caused by a failure to process distress cues of others, meaning that they are unable to understand sad and fearful expressions and consequently suppress their aggression (Blair 1995). It is important to mention that they are nevertheless able to detect stimuli being threatening for themselves. ## Summary We hope that this chapter gave you an overview and answered the question we posed at the beginning. As one can see this young field of cognitive is wide and not yet completely researched. Many different theories were proposed to explain emotions and motivation like the James-Lange Theory which claims that bodily changes lead to emotional experiences. This theory led to the Two-Factor-Theory which in contrast says that bodily changes only support emotional experiences. Whereas the newest theory (Somatic marker) states that somatic markers support decision making. While analyzing emotions, one has to distinguish between conscious emotions, like a feeling, and unconscious aspects, like the detection of threat. Presently, researchers distinguish six basic emotions that are independent from cultural aspects. In comparison to this basic emotions other emotions also comprehend social awareness. So, emotions are not only important for our survival but for our social live, too. Reading faces helps us to communicate and interpret behaviour of other people. Many disorders impair this ability leaving the afflicted person with an inability to integrate himself into the social community. Another important part in understanding emotions is awareness; we only pay attention on new things in order to avoid getting unimportant information. Moods also affect our memory - we can remember things better if we are in the same mood as in the situation before and if the things we want to remember are connoted in the same way as our current mood. We also outlined the topic of motivation which is crucial to initiate and uphold our mental and corporal activities. Motivation consists of two parts: drives (biological needs) and motives (primarily social and psychological mechanisms). One important theory is the Maslow Hierarchy of Needs; it states that higher motivations are only aspired if lower needs are satisfied. As this chapter only dealt with mood and memory, the next chapter deals with memory and language. ## References ### Books - Zimbardo, Philip G. (1995, 12th edition). Psychology and Life. Inc. Scott, Foresman and Company, Glenview, Illinois. - Banich,Marie T. (2004). Cognitive Neuroscience and Neuropsychology. Housthon Mifflin Company. - Robert A. Wilson and Frank C. Keil. (2001). The MIT Encyclopedia of Cognitive Sciences (MITECS). Bradford Book. - Antonio R. Damasio. (1994) reprinted (2005). Descartes\' Error: Emotion, Reason and the Human Brain. Penguin Books. - Antonio R. Damasio. (1999). The Feeling of what Happens. Body and Emotion in the Making of Consciousness. Harcourt Brace & Company. - Aaron Ben-Ze\'ev (Oct 2001). The Subtlety of Emotions.(MIT CogNet). - Ward, J. (2006). The Students Guide to Cognitive Neuroscience. Hove: Psychology Press. ### Journals - The emotional brain. Tim Dalgleish. - $1$ Leonard, C.M., Rolls, E.T., Wilson, F.A.W. & Baylis, C.G. Neurons in the amygdala of the monkey with responses selective for faces. Behav. Brain Res. 15, 159-176 (1985) - (2)Adolphs, R., Tranel, D., Damasio, H. & Damasio, A. Impaired recognition of emotion in facial expressions following bilateral damage of the human amygdala. Nature 372, 669-672 (1994) - (3)Young, A. W. et al. Face processing impairments after amygdalotomy. Brain 118, 15-24 (1995) - (4)Calder, A. J. et al. Facial emotion recognition after bilateral amygdala damage: Differentially severe impairment of fear. Cognit. Neuropsychol. 13, 699-745 (1996) - (5)Scott, S. K. et al. Impaired auditory recognition of fear and anger following bilateral amygdala lesions. Nature 385, 254-257 (1997) - (6)Cahill, L., Babinsky, R., Markowitsch, H. J. & McGaugh, J. L. The amygdala and emotional memory. Nature 377, 295-296 (1995) - (7)Wood, Jacqueline N. and Grafman, Jordan (02/2003). Human Prefrontal Cotex. Nature Reviews/ Neuroscience - (8)Brothers, L. , Ring, B. & Kling, A. Response of neurons in the macaque amygdala to complex social stimuli. Behav. Brain Res. 41, 199-213 (1990) - (9)Bear, M.F., Connors, B.W., Paradiso, M.A. (2006, 3rd edition). Neuroscience. Exploring the Brain. Lippincott Wiliams & Wilkins. ### Links - Dana Foundation and the Dana Alliance: The Site for Brain News - Brain Facts: PDF [^1]: Independent variables are the circumstance of major interest in an experiment. The Participant does only react on them, but cannot actively change them. They are independent of his behaviour. [^2]: The measured behaviour is called the dependent variable. [^3]: At the humoral response hypothalamic neurons stimulate or inhibit the release of pituitary hormones into the bloodstream and at the visceromotor response neurons in the hypothalamus adjust the balance of sympathetic and parasympathetic outputs of the autonomic nervous system (ANS). [^4]: αMSH neurons and CART neurons of the arcuate nucleus. αMSH(alpha-malanocyte-stimulating hormone) and CART(cocaine- and amphetamine-regulated transcript) are anoretic peptides, which activate the pituitary hormones TSH(thyroid-stimulating hormone) and ACTH(adrenocorticotropic hormone), that have the effect of raising the metabolic rate of cells throughout the body. [^5]: NPY neurons and AgRP neurons. NPY(neuropeptide Y) and AgRP(agouti-related peptide) are orexigenic peptides, which inhibit the secretion of TSH and ACTH. [^6]: MCH(melanin-concentrating hormone) neurons, which have extremely widespread connections in the brain, including direct monosynaptic innervation of most of the cerebral cortex, that is involved in organizing and initiating goal-directed behaviors, such as raiding the refrigerator. [^7]: The NPY- and AgRP neurons. [^8]: The pancreatic hormone insulin, released by β cells of the pancreas, acts directly on the arcuate and ventromedial nuclei of the hypothalamus. It appears that it operates in much the same way as leptin to regulate feeding behavior, with the difference that its primary stimulus for realisng is increased blood glucose level.
# Cognitive Psychology and Cognitive Neuroscience/Memory +:------------------------------+:----:+------------------------------:+ \| Previous \| [O \| [Next \| \| Chap \| verv \| C \| \| ter \| niti \| mory_and_Language "wikilink") \| \| \| ve_P \| \| \| \| sych \| \| \| \| olog \| \| \| \| y_an \| \| \| \| d_Co \| \| \| \| gnit \| \| \| \| ive_ \| \| \| \| Neur \| \| \| \| osci \| \| \| \| ence \| \| \| \| "wi \| \| \| \| kili \| \| \| \| nk") \| \| +-------------------------------+------+-------------------------------+ # Introduction Imagine our friend Knut, who we have already introduced in earlier chapters of this book, hastily walking through his apartment looking everywhere for a gold medal that he has won many years ago at a swimming contest. The medal is very important to him, since it was his recently deceased mother who had insisted on him participating. The medal reminds him of the happy times in his life. But now he does not know where it is. He is sure that he had last seen it two days ago but, searching through his recent experiences, he is not able to recall where he has put it.\ So what exactly enables Knut to remember the swimming contest and why does the medal trigger the remembrance of the happy times in his life? Also, why is he not able to recall where he has put the medal, even though he is capable of scanning through most of his experiences of the last 48 hours?\ Memory, with all of its different forms and features, is the key to answering these questions. When people talk about memories, they are subconsciously talking about \"the capacity of the nervous system to acquire and retain usable skills and knowledge, which allows living organisms to benefit from experience\".[^1] Yet, how does this so-called memory function? In the process of answering this question, many different models of memory have evolved. Distinctions are drawn between Sensory Memory, Short Term Memory, and Long Term Memory based on the period of time information is accessible after it is first encountered. Sensory Memory, which can further be divided into Echoic and Iconic Memory, has the smallest time span for accessibility of information. With Short Term and Working Memory, information is accessible seconds to minutes after it is first encountered. While Long Term Memory, has an accessibility period from minutes to years to decades. This chapter discusses these different types of memory and further gives an insight into memory phenomena like False Memory and Forgetting. Finally, we will consider biological foundations that concern memory in human beings and the biological changes that occur when learning takes place and information is stored. # Types of Memory In the following section, we will discuss the three different types of memory and their respective characteristics: Sensory Memory, Short Term (STM) or Working Memory (WM) and Long Term Memory (LTM). ## Sensory Memory This type of memory has the shortest retention time, only milliseconds to five seconds. Roughly, Sensory Memory can be subdivided into two main kinds: framed\\|Sensory Memory - Iconic Memory (visual input) - Echoic Memory (auditory input) While Iconic and Echoic Memory have been well researched, there are other types of Sensory Memory, like haptic, olfactory, etc., for which no sophisticated theories exist so far.\ It should be noted, though, that according to the Atkinson and Shiffrin (1968)`<ref>`{=html}Atkinson, R. C. & Shiffrin, R. M. (1968). Human memory: A proposed system and its control processes. : In K. Spence & J. Spence (Eds.), The psychology of learning and motivation (Volume 2). New York: Academic Press. ```{=html} </ref> ``` Sensory Memory was considered to be the same thing as Iconic Memory. Echoic Memory was added to the concept of Sensory Memory due to research done by Darwin and others (1972).`<ref>`{=html}Darwin, C. J., Turvey, M. T., & Crowder, R. G. (1972). An auditory analogue of the Sperling partial report procedure: : Evidence for brief auditory storage. Cognitive Psychology, 3, 255-267. ```{=html} </ref> ``` Let us consider the following intuitive example for Iconic Memory: Probably we all know the phenomenon that it seems possible to draw lines, figures or names with lighted sparklers by moving the sparkler fast enough in a dark environment. Physically, however, there are no such things as lines of light. So why can we nevertheless see such figures? This is due to Iconic Memory. Roughly speaking, we can think of this subtype of memory as a kind of photographic memory, but one which only lasts for a very short time (milliseconds, up to a second). The image of the light of a sparkler remains in our memory (persistence of vision) and thus makes it seem to us like the light leaves lines in the dark. The term \"Echoic Memory\", as the name already suggests, refers to auditory input. Here the persistence time is a little longer than with Iconic Memory (up to five seconds).\ At the level of Sensory Memory no manipulation of the incoming information occurs, it is transferred to the Working Memory. By 'transfer' it is meant that the amount of information is reduced because the capacity of the working memory is not large enough to cope with all the input coming from our sense organs. The next paragraph will deal with the different theories of selection when transferring information from Sensory Memory to Working Memory.\ One of the first experiments researching the phenomenon of Attention was the Shadowing Task (Cherry et al., 1953).`<ref>`{=html}Cherry, E. C. (1953). Some experiments on the recognition of speech with one and with two ears. : Journal of Accoustical Society of America, 25, 975-979. ```{=html} </ref> ``` This experiment deals with the filtering of auditory information. The subject is wearing earphones, getting presented a different story on each ear. He or she has to listen to and repeat out loud the message on one ear (shadowing). When asked for the content of the stories of both ears only the story of the shadowed side can be repeated; participants do not know about the content of the other ear's story. From these results Broadbent concluded the Filter Theory (1958).[^2] This theory proposes that the filtering of information is based on specific physical properties of stimuli. For every frequency there exists a distinct nerve pathway. The attention control selects which pathway is active and can thereby control which information is passed to the Working Memory. This way it is possible to follow the utterance of one person with a certain voice frequency even though there are many other sounds in the surrounding. But imagine a situation in which the so called cocktail party effect applies: having a conversation in a loud crowd at a party and listening to your interlocutor you will immediately switch to listening to another conversation if the content of it is semantically relevant to you, e.g. if your name is mentioned.\ So it is found that filtering also happens semantically. The above mentioned Shadowing Task was changed so that the semantic content of a sentence was split up between the ears, and the subject, although shadowing, was able to repeat the whole sentence because he or she was following the semantic content unconsciously.\ Reacting to the effect of semantic filtering, new theories were developed. Two important theories are the Attenuation Theory (Treisman, 1964)`<ref>`{=html}Treisman, A. M. (1964). Monitoring and storage of irrelevant messages and selective attention. : Journal of Verbal Learning and Verbal Behaviour, 3, 449-459. ```{=html} </ref> ``` and the Late Selection Theory (Deutsch & Deutsch, 1963).[^3] The former proposes that we attenuate information which is less relevant, but do not filter it out completely. Thereby also semantic information of ignored frequencies can be analyzed but not as efficiently as those of the relevant frequencies. The Late Selection Theory presumes that all information is analyzed first and afterwards the decision of the importance of information is made. Treisman and Geffen did an experiment to find out which one of the theories holds. The experiment was a revision of the Shadowing Task. Again the subjects have to shadow one ear but in contrast they also have to pay attention to a certain sound which could appear on either ear. If the sound occurs the subject has to react in a certain way (for example knock on the table). The result is that the subject identifies the sound on the shadowed ear in 87% of all cases and can only do this in 8% of the cases on the ignored side. This shows that the information on the ignored side must be attenuated since the rate of identification is lower. If the Late Selection Theory were to hold then the subject would have to analyze all information and would have to be able to identify the same amount on the ignored side as on the shadowed side. Since this is not the case the Attenuation Theory by Treisman explains the empirical results more accurately. framed\\|center\\|Illustration of the Attention Control Model by a) Treisman - Attenuation Theory and b) Deutsch & Deutsch -- Late Selection Theory. ## Short Term Memory The Short Term Memory (STM) was initially discussed by Attkinson and Shiffrin (1968).`<ref>`{=html}Atkinson, R. C. & Shiffrin, R. M. (1968). Human memory: A proposed system and its control processes. : In K. Spence & J. Spence (Eds.), The psychology of learning and motivation (Volume 2). New York: Academic Press. ```{=html} </ref> ``` The Short Term Memory is the link between Sensory Memory and Long Term Memory (LTM). Later Baddeley proposed a more sophisticated approach and called the interface Working Memory (WM). We will first look at the classical Short Term Memory Model and then go on to the concept of Working Memory. As the name suggests, information is retained in the Short Term Memory for a rather short period of time (15--30 seconds). framed\\|Short Term Memory If we look up a phone number in the phone book and hold it in mind long enough for dialling the number, it is stored in the Short Term Memory. This is an example of a piece of information which can be remembered for a short period of time. According to George Miller (1956)`<ref>`{=html}Miller, G. A. (1956). The magical number seven, plus or minus two: Some limits on our capacity for processing information. : Psychological Review, 63, 81-97. ```{=html} </ref> ``` the capacity of the Short Term Memory is five to nine pieces of information (The magical number seven, plus or minus two). The term \"pieces of information" or, as it is also called, chunk might strike one as a little vague. All of the following are considered as chunks: single digits or letters, whole words or even sentences and the like. It has been shown by experiments also done by Miller that chunking (the process of bundeling information) is a useful method to memorize more than just single items in the common sense. Gobet et al. defined a chunk as \"a collection of elements that are strongly associated with one another but are weakly associated with other chunks\" (Goldstein, 2005).[^4] A very intuitive example of chunking information is the following:\ Try to remember the following digits: - 0 3 1 2 1 9 8 2 But you could also try another strategy to remember these digits: - 03\. 12. 1982. With this strategy you bundled eight pieces of information (eight digits) to three pieces with help to remember them as a date schema.\ A famous experiment concerned with chunking was conducted by Chase and Simon (1973)`<ref>`{=html}Chase, W. G. & Simon, H.A. (1973). The mind's eye in chess. In W. G. Chase (Ed.), Visual information processing. : New York: Academic Press. ```{=html} </ref> ``` with novices and experts in chess playing. When asked to remember certain arrangements of chess pieces on the board, the experts performed significantly better that the novices. However, if the pieces were arranged arbitrarily, i.e. not corresponding to possible game situations, both the experts and the novices performed equally poorly. The experienced chess players do not try to remember single positions of the figures in the correct game situation, but whole bundles of figures as already seen before in a game. In incorrect game situations this strategy cannot work which shows that chunking (as done by experienced chess players) enhances the performance only in specific memory tasks. ```{=html} <!-- --> ``` From Short Term Memory to Baddeley's Working Memory Model: Baddeley and Hitch (1974)`<ref>`{=html}Baddeley, A. D. & Hitch, G. (1974). Working memory. In G. A. Bower (Ed.), Recent advances in learning and motivation (Vol. 8). : New York: Academic Press. ```{=html} </ref> ``` drew attention to a problem with the Short Term Memory Model. Under certain conditions it seems to be possible to do two different tasks simultaneously, even though the STM, as suggested by Atkinson and Shiffrin, should be regarded as a single, undivided unit. An example for the performance of two tasks simultaneously would be the following: a person is asked to memorize four numbers and then read a text (unrelated to the first task). Most people are able to recall the four numbers correctly after the reading task, so apparently both memorizing numbers and reading a text carefully can be done at the same time. According to Baddeley and Hitch the result of this experiment indicates that the number-task and the reading-task are handled by two different components of Short Term Memory. So they coined the term \"Working Memory\" instead of \"Short Term Memory\" to indicate that this kind of Memory enables us to perform several cognitive operations at a time with different parts of the Working Memory. ## Working Memory According to Baddeley, Working Memory is limited in its capacity (the same limitations hold as for Short Term Memory) and the Working Memory is not only capable of storage, but also of the manipulation of incoming information. Working Memory consists of three parts:\ framed\\|Working Memory - Phonological Loop - Visuospatial Sketch Pad - Central Executive We will consider each module in turn:\ The Phonological Loop is responsible for auditory and verbal information, such as phone numbers, people's names or general understanding of what other people are talking about. We could roughly say that it is a system specialized for language. This system can again be subdivided into an active and a passive part. The storage of information belongs to the passive part and fades after two seconds if the information is not rehearsed explicitly. Rehearsal, on the other hand, is regarded as the active part of the Phonological Loop. The repetition of information deepens the memory. There are three well-known phenomena that support the idea that the Phonological Loop is specialized for language: The phonological similarity effect, the word-length effect and articulatory suppression. When words that sound similar are confused, we speak of the phonological similarity effect. The word-length effect refers to the fact that it is more difficult to memorize a list of long words and better results can be achieved if a list of short words is memorized. Let us look at the phenomenon of articulatory suppression in a little more detail. Consider the following experiment:\ Participants are asked to memorize a list of words while saying \"the, the, the \..." out loud. What we find is that, with respect to the word-length effect, the difference in performance between lists of long and short words is levelled out. Both lists are memorized equally poorly. The explanation given by Baddeley et al. (1986),[^5] who conducted this experiment, is that the constant repetition of the word \"the\" prevents the rehearsal of the words in the lists, independent of whether the list contains long or short words. The findings become even more drastic if we compare the memory-performance in the following experiment (also conducted by Baddeley and his co-workers in 1986):\ Participants were again asked to say out loud \"the, the, the \...\" But instead of memorizing words from a list of short or long words, their task was to remember words that were either spoken to them or shown to them written on paper. The results indicated that the participants' performances were significantly better if the words were presented to them and not read out aloud. Baddeley concluded from this fact that the performance in a memory task is improved if the two stimuli can be dealt with in distinct components of the Working Memory. In other words, since the reading of words is handled in the Visuospatial Sketch Pad, whereas the saying of \"the\" belongs to the Phonological Loop, the two tasks do not \"block\" each other. The rather bad performance of hearing words while speaking could be explained by the fact that both hearing and speaking are dealt with in the Phonological Loop and thus the two tasks conflict with each other, decreasing the performance of memorization.\ In the Visuospatial Sketch Pad, visual and spatial information is handled. This means that information about the position and properties of objects can be stored. As we have seen above, performance decreases if two tasks that are dealt with in the same component are to be done simultaneously. Let us consider a further example that illustrates this effect. Brandimonte and co-workers (1992)`<ref>`{=html}Brandimonte, M. A., Hitch, G. J., & Bishop, D. V. M. (1992). Influence of short-term memory codes on visual image processing: : Evidence from image transformation tasks. Journal of Experimental Psychology: Learing, Memory, and Cognition, 18, 157-165. ```{=html} </ref> ``` conducted an experiment where participants were asked to say out loud \"la, la, la\..." At the same time they were given the task of subtracting a partial image from a given whole image. The subtraction had to be done mentally because the two images were presented only for a short time. The interesting result was that the performance not only didn\'t decrease while saying \"la, la, la \...\" when compared to doing the subtraction-task alone, but the performance even increased. According to Brandimonte this was due to the fact that the subtraction task was easier if handled in the Visuospatial Sketch Pad as opposed to the Phonological Loop (both the given and the resulting pictures were such that they could also be named, i.e. verbalized, a task that belongs to the Phonological Loop). As mentioned above, because of the fact that the subtraction of a partial image from a whole given image is easier if done visually, the performance increased if participants were forced to visually perform that task, i.e. if they were forced to use the component that is suited best for the given task. We have seen that the Phonological Loop and the Visuospatial Sketch Pad deal with rather different kinds of information which nonetheless have to somehow interact in order to do certain tasks. The component that connects those two systems is the Central Executive. The Central Executive co-ordinates the activity of both the Phonological Loop and the Visuospatial Sketch Pad. Imagine the following situation: You are driving a car and your friend in the passenger seat has the map and gives you directions. The directions are given verbally, i.e. they are handled by the Phonological Loop, while the perception of the traffic, street lights, etc. is obviously visual, i.e. dealt with in the Visuospatial Sketch Pad. If you now try to follow the directions given to you by your friend it is necessary to somehow combine both kinds of information, the verbal and the visual information. This important connection of the two components is done by the Central Executive. It also links the Working Memory to Long Term Memory, controls the storage in Long Term Memory and the retrieval from it. The process of storage is influenced by the duration of holding information in Working Memory and the amount of manipulation of the information. The latter is stored for a longer time if it is semantically interpreted and viewed with relation to other information already stored in Long Term Memory. This is called Deep Processing. Pure syntactical processing (reading a text for typos) is called Shallow Processing. Baddeley proposes also further capabilities for the Central Executive: - Initiating movement - Control of conscious attention Problems which arise with the Working Memory approach: In theory, all information has to pass the Working Memory in order to be stored in the Long Term Memory. However, cases have been reported where patients could form Long Term Memories even though their STM-abilities were severely reduced. This clearly poses a problem to the modal model approach. It was suggested by Shallice and Warrington (1970)`<ref>`{=html}Shallice, T., & Warrington, E. K. (1970). Independent functioning of verbal memory stores: A neuropsychological study. : Quarterly Journal of Experimental Psychology,22, 261-273. ```{=html} </ref> ``` that there must be another possible way for information to enter Long Term Memory than via Working Memory. ## Long Term Memory As the name already suggest, Long Term Memory is the system where memories are stored for a long time. \"Long\" in this sense means something between a few minutes and several years or even decades to lifelong. framed\\|Long Term Memory Similar to Working Memory, Long Term Memory can again be subdivided into different types. Two major distinctions are made between Declarative (conscious) and Implicit (unconscious) Memory. Those two subtypes are again split into two components each: Episodic and Semantic Memory with respect to Declarative Memory and Priming Effects, and Procedural Memory with respect to Implicit Memory. In contrast to Short Term or Working Memory, the capacity of Long Term Memory is theoretically infinite. The opinions as to whether information remains in the Long Term Memory forever or whether information can get deleted differ. The main argument for the latter opinion is that apparently not all information that was ever stored in LTM can be recalled. However, theories that regard Long Term Memories as not being subject to deletion emphasize that there might be a useful distinction between the existence of information and the ability to retrieve or recall that information at a given moment. There are several theories about the "forgetting" of information. These will be covered in the section "Forgetting and False Memory". #### Declarative Memory Let us now consider the two types of Declarative Memory. As noted above, those two types are Episodic and Semantic Memory. Episodic Memory refers to memories for particular events that have been experienced by somebody (autobiographical information). Typically, those memories are connected to specific times and places. Semantic Memory, on the other hand, refers to knowledge about the world that is not connected to personal events. Vocabularies, concepts, numbers or facts would be stored in the Semantic Memory. Another subtype of memories stored in Semantic Memory is that of the so called Scripts. Scripts are something like blueprints of what happens in a certain situation. For example, what usually happens if you visit a restaurant (You get the menu, you order your meal, eat it and you pay the bill). Semantic and Episodic Memory are usually closely related to one another, i.e. memory of facts might be enhanced by interaction with memory about personal events and vice versa. For example, the answer to the factual question of whether people put vinegar on their chips might be answered positively by remembering the last time you saw someone eating fish and chips. The other way around, good Semantic Memory about certain things, such as football, can contribute to more detailed Episodic Memory of a particular personal event, like watching a football match. A person that barely knows the rules of that game will most probably have a less specific memory for the personal event of watching the game than a football-expert will. #### Implicit Memory We now turn to the two different types of Implicit Memory. As the name suggests, both types are usually active when unconscious memories are concerned. This becomes most evident for Procedural Memory, though it must be said that the distinction between both types is not as clearly cut as in the case of Declarative Memory and that often both categories are collapsed into the single category of Procedural Memory. But if we want to draw the distinction between Priming Effects and Procedural Memory, the latter category is responsible for highly skilled activities that can be performed without much conscious effort. Examples would be the tying of shoelaces or the driving of a car, if those activities have been practiced sufficiently. It is some kind of movement plan. As regards the Priming Effect, consider the following experiment conducted by Perfect and Askew (1994):[^6]\ Participants were asked to read a magazine without paying attention to the advertisements. After that, different advertisements were presented to them; some had occurred in the magazine, others had not. The participants were told to rate the presented advertisement with respect to different criteria such as how appealing, how memorable or eye-catching they were. The result was that in general those advertisements that had been in the magazine received higher rankings than those that had not been in the magazine. Additionally, when asked which advertisements the participants had actually seen in the magazine, the recognition was very poor (only 2.8 of the 25 advertisements were recognized). This experiment shows that the participants performed implicit learning (as can be seen from the high rankings of advertisements they had seen before) without being conscious of it (as can be seen from the poor recognition rate). This is an example of the Priming Effect.\ framed\\|center\\|Final overview of all different types of memory and their interaction # Forgetting and False Memory As important as memory is, also the process of Forgetting is present to everybody.\ Therefore one might wonder: - Why do we forget at all? - What do we forget? - How do we forget? Why do we forget at all? One might come up with something you could call "mental hygiene". It is not useful to remember every little detail of your life and your surrounding, but rather a disadvantage because you maybe would not be able to remember the important things as quickly or even quick enough but have an overload of facts in your memory. Therefore it is important that unused memories are "cleaned up" so that only relevant information is stored. What do we forget and how? There are different theories about how things are forgotten. One theory proposes that the capacity of the Long Term Memory is infinite. This would mean that actually all memories are stored in the LTM but some information cannot be recalled (anymore) due to factors to be mentioned in the following paragraphs: There are two main theories about the causes of forgetting: - The _Trace Decay Theory_ states that you need to follow a certain path, or trace, to recall a memory. If this path has not been used for some time, one would say that the activity of the information decreases (it fades (-\>decays)), which leads to difficulty or the inability to recall the memory. !Memory Interference{width="450"} ```{=html} <!-- --> ``` - The _Interference Theory_ proposes that all memories interfere with each other. One distinguishes between two kinds of interferences: - Proactive Interference: : Earlier memories influence new ones or hinder one to make new ones. - Retroactive Interference: : Old memories are changed by new ones, maybe even so much that the original one is completely 'lost'. ```{=html} <!-- --> ``` - Which of the two theories applies in your opinion? - Do you agree with a mixture of the two? !Ebbinghaus Curve of forgetting{width="450"} In 1885 Herrmann Ebbinghaus did several self-experiments to research human forgetting. He memorized a list of meaningless syllables, like "WUB" and "ZOF", and tried to recall as many as possible after certain intervals of time for several weeks. He found out that forgetting can be described with an almost logarithmic curve, the so called forgetting curve which you can see on the left. These theories about forgetting already make clear that memory is not a reliable recorder but it is a construction based on what actually happened plus additional influences, such as other knowledge, experiences, and expectations. Thus false memories are easily created. In general there are three types of tendencies towards which people's memories are changed. These tendencies are called ## Biases in memory One distinguishes between three major types: - Egocentric Bias : It makes one see his or herself in the best possible light. - Consistency Bias : Because of which one perceives his or her basic attitudes to remain persistent over time. - Positive Change Bias : It is cause for the fact that one perceives things to be generally improving. (For a list of more known memory biases see: List of memory biases) There are moments in our lives that we are sure we will never forget. It is generally perceived that the memories of events that we are emotionally involved with are remembered for a longer time than others and that we know every little detail of them. These kinds of memories are called Flashbulb Memories.\ The accuracy of the memories is an illusion, though. The more time passes, the more these memories have changed while our feeling of certainty and accuracy increases. Examples for Flashbulb Memories are one's wedding, the birth of one's child or tragedies like September 11th. Interesting changes in memory can also occur due to Misleading Postevent Information (MPI). After an event information given another person can so to say intensify your memory in a certain respect. This effect was shown in an experiment by Loftus and Palmer (1974):`<ref>`{=html}Loftus, E. F., & Palmer, J. C. (1974). Reconstruction of an automobile destruction: : An example of the interaction between language and memory. Journal of Verbal Learning and Verbal Behavior, 13, 585-589. ```{=html} </ref> ``` The subjects watched a film in which there were several car accidents. Afterwards they were divided into three groups that were each questioned differently. While the control group was not asked about the speed of the cars at all, in the other groups questions with a certain key word were posed. One group was asked how fast the cars were going when they hit each other, while in the other question the verb "smashed" was used. One week later all participants were asked whether they saw broken glass in the films. Both the estimation of speed and the amount of people claiming to have seen broken glass increased steadily from the control group to the third group.\ Based on this Misinformation Effect the Memory Impairment Hypothesis was proposed.\ This hypothesis states that suggestible and more detailed information that one receives after having made the actual memory can replace the old memory.\ Keeping the possible misleading information in mind, one can imagine how easily eyewitness testimony can be (purposely or accidentally) manipulated. Depending on which questions the witnesses are asked they might later on remember to see, for example, a weapon or not. These kinds of changes in memory are present in everyone on a daily basis. But there are other cases: People with a lesion in the brain sometimes suffer from Confabulation. They construct absurd and incomplete memories that can even contradict with other memories or with what they know. Although the people might even be aware of the absurdness of their memories they are still firmly convinced of them. (See Helen Phillips\' article Mind fiction: Why your brain tells tall tales) ## Repressed and Recovered Memories If one cannot remember an event or detail, it does not mean that the memory is completely lost. Instead one would say that these memories are repressed, which means that they cannot easily be remembered. The process of remembering in these cases is called recovery.\ Recovering of a repressed memory usually occurs due to a retrieval cue. This might be an object or a scene that reminds one of something which has happened long ago.\ Traumatic events, which happened during childhood for example, can be recovered with the help of a therapist. This way, perpetrators have been brought to trial after decades.\ Still, the correctness of the "recovered" memory is not guaranteed: as we know, memory is not reliable and if the occurrence of an event is suggestible one might produce a false memory.\ Look at the illustration to the right to be able to relate to these processes. !How did the memory for an event become what it is? Other than on a daily basis errors in memory and amnesia are due to damages in the brain. The following paragraphs will present the most important brain regions enabling memory and mention effects of damage to them. # Some neurobiological facts about memory In this section, we will first consider how information is stored in synapses and then talk about two regions of the brain that are mainly involved in forming new memories, namely the amygdala and the hippocampus. To show what effects memory diseases can have and how they are classified, we will discuss a case study of amnesia and two other common examples for amnesic diseases: Karsakoff's amnesia and Alzheimer's disease. ## Information storage The idea that physiological changes at synapses happen during learning and memory was first introduced by Donald Hebb.[^7] It was in fact shown that activity at a synapse leads to structural changes at the synapse and to enhanced firing in the postsynaptic neuron. Since this process of enhanced firing lasts for several days or weeks, we talk about Long Term Potentiation (LTP). During this process, existing synaptic proteins are altered and new proteins are synthesized at the modified synapse. What does all this have to do with memory? It has been discovered that LTP is most easily generated in regions of the brain which are involved in learning and memory - especially the hippocampus, about which we will talk in more detail later. Donald Hebb found out that not only a synapse of two neurons is involved in LTP but that a particular group of neurons is more likely to fire together. According to this, an experience is represented by the firing of this group of neurons. So it works according to the principle: "what wires together fires together". ## Amygdala The amygdala is involved in the modulation of memory consolidation. !Location of the amygdala in the human brain Following any learning event, the Long Term Memory for the event is not instantaneously formed. Rather, information regarding the event is slowly assimilated into long term storage over time, a process referred to as memory consolidation, until it reaches a relatively permanent state. During the consolidation period, memory can be modulated. In particular, it appears that emotional arousal following a learning event influences the strength of the subsequent memory for that event. Greater emotional arousal following a learning event enhances a person\'s retention of that event. Experiments have shown that administration of stress hormones to individuals, immediately after they learn something, enhances their retention when they are tested two weeks later. The amygdala, especially the basolateral nuclei, is involved in mediating the effects of emotional arousal on the strength of the memory for the event. There were experiments conducted by James McGaugh on animals in special laboratories. These laboratories have trained animals on a variety of learning tasks and found that drugs injected into the amygdala after training affect the animal's subsequent retention of the task. These tasks include basic Pavlovian Tasks such as Inhibitory Avoidance, where a rat learns to associate a mild footshock with a particular compartment of an apparatus, and more complex tasks such as spatial or cued water maze, where a rat learns to swim to a platform to escape the water. If a drug that activates the amygdala is injected into the amygdala, the animals had better memory for the training in the task. When a drug that inactivated the amygdala was injected, the animals had impaired memory for the task. Despite the importance of the amygdala in modulating memory consolidation, however, learning can occur without it, although such learning appears to be impaired, as in fear conditioning impairments following amygdala damage. Evidence from work with humans indicates a similar role of the amygdala in humans. Amygdala activity at the time of encoding information correlates with retention for that information. However, this correlation depends on the relative \"emotionality\" of the information. More emotionally-arousing information increases amygdalar activity, and that activity correlates with retention. ## Hippocampus Psychologists and neuroscientists dispute over the precise role of the hippocampus, but, generally, agree that it plays an essential role in the formation of new memories about experienced events (Episodic or Autobiographical Memory). !Position of the hippocampus in the human brain{width="185"} Some researchers prefer to consider the hippocampus as part of a larger medial temporal lobe memory system responsible for general declarative memory (memories that can be explicitly verbalized --- these would include, for example, memory for facts in addition to episodic memory). Some evidence supports the idea that, although these forms of memory often last a lifetime, the hippocampus ceases to play a crucial role in the retention of the memory after a period of consolidation. Damage to the hippocampus usually results in profound difficulties in forming new memories (anterograde amnesia), and normally also affects access to memories prior to the damage (retrograde amnesia). Although the retrograde effect normally extends some years prior to the brain damage, in some cases older memories remain intact - this sparing of older memories leads to the idea that consolidation over time involves the transfer of memories out of the hippocampus to other parts of the brain. However, researchers have difficulties in testing the sparing of older memories and, in some cases of retrograde amnesia, the sparing appears to affect memories formed decades before the damage to the hippocampus occurred, so its role in maintaining these older memories remains controversial. \ ## Amnesia As already mentioned in the preceding section about the hippocampus, there are two types of amnesia - retrograde and antrograde amnesia. framed\\|center\\|Different types of Amnesia Amnesia can occur when there is damage to a number of regions in the medial temporal lobe and their surrounding structures. The patient H.M. is probably one of the best known patients who suffered from amnesia. Removing his medial temporal lobes, including the hippocampus, seemed to be a good way to treat the epilepsy. What could be observed after this surgery was that H.M. was no longer able to remember things which happened after his 16th birthday, which was 11 years before the surgery. So given the definitions above one can say that he suffered retrograde amnesia. Unfortunately, he was not able to learn new information due to the fact that his hippocampus was also removed. H.M. therefore suffered not only from retrograde amnesia, but also from anterograde amnesia. His Implicit Memory, however, was still working. In procedural memory tests, for example, he still performed well. When he was asked to draw a star on a piece of paper which was shown to him in a mirror, he performed as bad as every other participant in the beginning. But after some weeks his performance improved even though he could not remember having done the task many times before. Thus, H.M.'s Declarative Memory showed severe deficits but his Implicit Memory was still fine. Another quite common cause of amnesia is the Korsakoff's syndrome or also called Korsakoff's amnesia. Long term alcoholism usually elicits this Korsakoff's amnesia due to a prolonged deficiency of vitamin B1. This syndrome is associated with the pathology of the midline diencephalon including the dorsomedial thalamus. Alzheimer's disease is probably the best known type of amnesia because it is the most common type in our society. Over 40 percent of the people who are older than 80 are affected by Alzheimer's disease. It is a neurodegenerative disease and the region in the brain which is most affected is the entorhinal cortex. This cortex forms the main input and output of the hippocampus and so damages here are mostly severe. Knowing that the hippocampus is especially involved in forming new memories one can already guess the patients have difficulties in learning new information. But in late stages of Alzheimer's disease also retrograde amnesia and even other cognitive abilities, which we are not going to discuss here, might occur. center\\|framed\\|This figure shows the brain structures which are involved in forming new memories Final checklist of what you should keep in mind ------------------------------------------------------------------------ 1. Why does memory exist? 2. What is sensory memory? 3. What is the distinction between Short Term memory and Working Memory? 4. What is Long Term Memory and which brain area(s) are involved in forming new memories? 5. Remember the main results of the theory (For example: What does the Filter Theory show?) 6. Don't forget why we forget! # Links - Memory in Psychology,Encyclopedia of Psychology - Psychology 101 Memory and Forgetting, AllPsych ONLINE - Human Memory website of the University of Amsterdam # References ```{=html} <references/> ``` Everyday memory - Eyewitness testimony Introduction Witness psychology is the study of human as an observer and reporter of events in life. It's about how detailed and accurate we register what is happening, how well we remember what we observed, what causes us to forget and remember the mistakes, and our ability to assess the reliability and credibility of others\' stories. It is the study of observation and memory for large and small events in life, from everyday trivialities to the dramatic and traumatic events that shook our lives (Magnussen, 2010) Basic concepts The eyewitness identification literature has developed a number of definitions and concepts that require explanation. Each definition and concept is described below. A lineup is a procedure in which a criminal suspect (or a picture of the suspect) is placed among other people (or pictures of other people) and shown to an eyewitness to see if the witness will identify the suspect as the culprit in question. The term suspect should not be confused with the term culprit. A suspect might or might not be the culprit, a suspect is suspected of being the culprit (Wells & Olson, 2003) Fillers are people in the lineup who are not suspects. Fillers, sometimes called foils or distractors, are known-innocent members of the lineup. Therefore, the identification of filler would not result in charges being brought against the filler. A culprit-absent lineup is one in which an innocent suspect is embedded among fillers and a culprit-present lineup is one in which a guilty suspect (culprit) is embedded among fillers. The primary literature sometimes calls these target-present and target-absent lineups (Wells & Olson, 2003). A simultaneous lineup is one in which all lineup members are presented to the eyewitness at once and is the most common lineup procedure in use by law enforcement. A sequential lineup, on the other hand, is one in which the witness is shown only one person at a time but with the expectation that there are several lineup members to be shown (Wells & Olson, 2003). A lineup's functional size is the number of lineup members who are "viable" choices for the eyewitness. For example, if the eyewitness described the culprit as being a tall male with dark hair and the suspect is the only lineup member who is tall with dark hair, then the lineup's functional size would be 1.0 even if there were 10 fillers. Today functional size is used generically to mean the number of lineup members who fit the eyewitness's description of the culprit (Wells & Olson, 2003). Mock witnesses are people who did not actually witness the crime but are asked to pick a person from the lineup based on the eyewitness's verbal description of the culprit. They are shown the lineup and are asked to indicate who is the offender. Mock witnesses are used to test the functional size of the lineup (Wells & Olson, 2003). The diagnosticity of suspect identification is the ratio of accurate identification rate with a culprit-present lineup to the inaccurate identification rate with a culprit- absent lineup. The diagnosticity of "not there" is the ratio of "not there" response rates with culprit-absent lineups to "not there" response rates with culprit-present lineups. The diagnosticity of filler identifications is the ratio of filler identification rates with culprit-absent lineups to filler identification rates with culprit-present lineups (Wells & Olson, 2003) Among variables that affect eyewitness identification accuracy, a system variable is one that is, or could be, under control of the criminal justice system, while an estimator variable is one that is not. Estimator variables include lighting conditions at the time of witnessing and whether the witness and culprit are of the same or of different races. System variables include instructions given to eyewitnesses prior to viewing a lineup and the functional size of a lineup. The distinction between estimator and system variables has assumed great significance in the eyewitness identification literature since it was introduced in the late 1970s . In large part, the prominence of this distinction attests to the applied nature of the eyewitness identification literature. Whereas the development of a literature on estimator variables permits some degree of post diction that might be useful for assessing the chances of mistaken identification after the fact, the development of a system variable literature permits specification of how eyewitness identification errors might be prevented in the first place (Wells & Olson, 2003). History and Reliability The criminal justice system relies heavily on eyewitness identification for investigating and prosecuting crimes. Psychology has built the only scientific literature on eyewitness identification and has warned the justice system of problems with eyewitness identification evidence. Recent DNA exoneration cases have corroborated the warnings of eyewitness identification researchers by showing that mistaken eyewitness identification was the largest single factor contributing to the conviction of innocent people (Wells & Olson, 2003). Psychological researchers who began programs in the 1970s, however, have consistently articulated concerns about the accuracy of eyewitness identification. Using various methodologies, such as filmed events and live staged crimes, eyewitness researchers have noted that mistaken identification rates can be surprisingly high and that eyewitnesses often express certainty when they mistakenly select someone from a lineup. Although their findings were quite compelling to the researchers themselves, it was not until the late 1990s that criminal justice personnel began taking the research seriously. This change in attitude about the psychological literature on eyewitness identification arose primarily from the development of forensic DNA tests in the 1990s (Wells & Olson, 2003). More than 100 people who were convicted prior to the advent of forensic DNA have now been exonerated by DNA tests, and more than 75% of these people were victims of mistaken eyewitness. The apparent prescience of the psychological literature regarding problems with eyewitness identification has created a rising prominence of eyewitness identification research in the criminal justice system. Because most crimes do not include DNA-rich biological traces, reliance on eyewitness identification for solving crimes has not been significantly diminished by the development of forensic DNA tests. The vast criminal justice system itself has never conducted an experiment on eyewitness identification (Wells & Olson, 2003). Research The experimental method has dominated the eyewitness literature, and most of the experiments are lab based. Lab-based experimental methods for studying eyewitness issues have strengths and weaknesses. The primary strength of experimental methods is that they are proficient at establishing cause--effect relations. This is especially important for research on system variables, because one needs to know in fact whether a particular system manipulation is expected to cause better or worse performance. In the real world, many variables can operate at the same time and in interaction with one another (Wells, Memon & Penrod, 2006) Multicollinearity can be quite a problem in archival/field research, because it can be very difficult to sort out which (correlated) variables are really responsible for observed effects. The control of variables that is possible in experimental research can bring clarity to causal relationships that are obscured in archival research. For example, experiments on stress during witnessing have shown, quite compellingly, that stress interferes with the ability of eyewitnesses to identify a central person in a stressful situation. However, when Yuille and Cutshall (1986) studied multiple witnesses to an actual shooting, they found that those who reported higher stress had better memories for details than did those who reported lower stress. Why the different results? In the experimental setting, stress was manipulated while other factors were held constant; in the actual shooting, those who were closer to the incident reported higher levels of stress (presumably because of their proximity) but also had a better view. Thus, in the actual case, stress and view covaried. The experimental method is not well suited to post diction with estimator variables---that is, there may be limits to generalizing from experiments to actual cases. One reason is that levels of estimator variables in experiments are fixed and not necessarily fully representative of the values observed in actual cases. In addition, it is not possible to include all interesting and plausible interactions among variables in any single experiment (or even in a modest number of experiments). Clearly, generalizations to actual cases are best undertaken on the basis of a substantial body of experimental research conducted across a wide variety of conditions and employing a wide variety of variables. Nevertheless, the literature is largely based on experiments due to a clear preference by eyewitness researchers to learn about cause and effect. Furthermore, ''ground truth'' (the actual facts of the witnessed event) is readily established in experiments, because the witnessed events are creations of the experimenters. This kind of ground truth is difficult, if not impossible, to establish when analyzing actual cases (Wells et al. 2006). Memory The world is complex. All natural situations or scenes contains infinitely more physical and social information than the brain is able to detect. The brain's ability to record information is limited. In studies of immediate memory for strings of numbers that have been read once, it turns out that most people begin to go wrong if the number of single digits exceeds five (Nordby, Raanaas & Magnussen, 2002). The limitations of what humans are capable to process, leads to an automatically selection of information. This selection is partially controlled by external factors, the factors in our environment that captures our attention (Magnussen, 2010). In the witness psychology we often talk about the weapon focus, in which eyewitnesses attend to the weapon, which reduces their memory for other information (Eysenck & Keane, 2010). The selection of information in a cognitive overload situation is also governed by psychological factors, the characteristics of the person who is observing. It is about the emotional state and the explicit and implicit expectations of what will happen. Psychologists call such expectations cognitive schemas. Cognitive schemas forms a sort of hypotheses or map of the world based on past experiences. These hypotheses or mental maps of the world determines what the brain chooses of the information, and how it interprets and if it will be remembered. When information is uncertain or ambiguous, the psychological factors are strong (Magnussen, 2010). Eyewitness testimony can be distorted via confirmation bias, i.e., event memory is influenced by the observer's expectation. A study made by Lindholm and Christianson (1998), Swedish and immigrant students saw a videotaped simulated robbery in which the perpetrator seriously wounded a cashier with a knife. After watching the video, participants were shown color photographs of eight men -- four Swedes and the remainder immigrants. Both Swedish and immigrant participants were twice as likely to select an innocent immigrant as an innocent swede. Immigrants are overrepresented in Swedish crime statistics, and this influenced participants' expectations concerning the likely ethnicity of the criminal (Eysenck & Keane, 2010) Bartlett (1932) explained why our memory is influenced by our expectations. He argued that we possess numerous schemas or packets of knowledge stored in long-term memory. These schemas lead us to form a certain expectations and can distort our memory by causing us to reconstruct an event details based on "what must have been true"(Eysenck & Keane, 2010). What we select of information, and how we interpret information is partially controlled by cognitive schemas. Many cognitive schemas are generalized, and for a large automated and non-conscious, as the expectation that the world around us is stable and does not change spontaneously. Such generalized expectations are basic economic and making sure we do not have to devote so much energy to monitor the routine events of daily life, but they also contribute to the fact that we in certain situations may overlook important, but unexpected information, or supplement the memory with details who is form consistent, but who actually don´t exist (Magnussen, 2010). Estimator variables First, estimator variables are central to our understanding of when and why eyewitnesses are most likely to make errors. Informing police, prosecutors, judges, and juries about the conditions that can affect the accuracy of an eyewitness account is important. Second, our understanding of the importance of any given system variable is, at least at the extreme, dependent on levels of the estimator variables. Consider a case in which a victim eyewitness is abducted and held for 48 hours by an unmasked perpetrator; the witness has repeated viewings of the perpetrator, lighting is good, and so on. We have every reason to believe that this witness has a deep and lasting memory of the perpetrator's face. Then, within hours of being released, the eyewitness views a lineup. Under these conditions, we would not expect system variables to have much impact. For instance, a lineup that is biased against an innocent suspect is not likely to lead this eyewitness to choose the innocent person, because her memory is too strong to be influenced by lineup bias. On the other hand, when an eyewitness's memory is weaker, system variables have a stronger impact. Psychologists have investigated the effects on identification accuracy of a large number of estimator variables, witness, crime, and perpetrator characteristics. Here we recount findings concerning several variables that have received significant research attention and achieved high levels of consensus among experts (based on items represented in a survey by Kassin, Tubb, Hosch, & Memon, 2001) or have been the subject of interesting recent research (Wells et al. 2006). References Eysenck, M.E., & Keane, M.T., (2010). Cognitive psychology. A student´s Handbook (6th Edn). New York: Psychological Press Magnussen, S., (2010). Vitnepsykologi. Pålitelighet og troverdighet I dagligliv og rettssal. Oslo: Abstrakt forlag as. Nordby, K., Raanaas, R.K. & Magnussen, S. (2002). The expanding telephone number. I: Keying briefly presented multiple-digit numbers. Behavior and Information Technology, 21, 27-38. Wells, G.L., Memon, A., & Penrod, S.D. ( 2006). Eyewitness Evidence. Improving Its Probative Value, 7(2), 45-75. Wells, G.L., & Olson, E.A., (2003). Eyewitness Testimony, 54:277-95. Doi: 10.1146/annurev.psych.54.101601.145028 [^1]: Quotation from www.wwnorton.com. [^2]: Broadbent, D. E. (1958). Perception and communication. New York: Pergamon. [^3]: Deutsch, J. A. & Deutsch, D. (1963). Attention: Some theoretical considerations. Psycological Review, 70, 80-90. [^4]: Goldstein, E. B. (2005). Cognitive Psychology. London: Thomson Leaning, page 157. [^5]: Baddeley, A. D. (1986). Working Memory. Oxford: Oxford University Press. [^6]: Perfect, T. J., & Askew, C. (1994). Print adverts: Not remembered but memorable. Applied Cognitive Psychology, 8, 693-703. [^7]: Hebb, D. O. (1948). Organization of behavior. New York: Wiley.
# Cognitive Psychology and Cognitive Neuroscience/Memory and Language +:------------------------------+:----:+------------------------------:+ \| Previous \| [O \| [Next \| \| Chapter \| (Cog \| roscience/Imagery "wikilink") \| \| \| niti \| \| \| \| ve_P \| \| \| \| sych \| \| \| \| olog \| \| \| \| y_an \| \| \| \| d_Co \| \| \| \| gnit \| \| \| \| ive_ \| \| \| \| Neur \| \| \| \| osci \| \| \| \| ence \| \| \| \| "wi \| \| \| \| kili \| \| \| \| nk") \| \| +-------------------------------+------+-------------------------------+ ## Introduction Introduction \"You need memory to keep track of the flow of conversation\" [^1] Maybe the interaction between memory and language does not seem very obvious at first, but this interaction is necessary when trying to lead a conversation properly. Memory is the component for storing and retrieving information. So to remember both things just said and information heard before which might be important for the conversation. Whereas language serves for following the conversational partner, to understand what he says and to reply to him in an understandable way.\ This is not a simple process which can be learned within days. In childhood everybody learns to communicate, a process lasting for years.\ So how does this work? Possible responses to the question of language acquisition are presented in this chapter.The section also provides an insight into the topic of malfunctions in the brain. Concerning dysfunctions the following questions arise: How can the system of language and memory be destroyed? What causes language impairments? How do the impairments become obvious? These are some of the topics dealt with in this chapter. Up to now, the whole profoundness of memory and language cannot be explored because the present financial resources are insufficient. And the connection between memory and language mostly becomes obvious when an impairment arises. So certain brain areas are explored when having a comparison between healthy brain and impaired brain. Then it is possible to find out what function this brain area has and how a dysfunction becomes obvious. ## Basics ### Memory Memory is the ability of the nervous system to receive and keep information. It is divided into three parts: Sensory memory, Short-term memory and Long-term memory. Sensory memory holds information for milliseconds and is separated into two components. The iconic memory is responsible for visual information, whereas auditory information is processed in the echoic memory. Short-term memory keeps information for at most half a minute. Long-term memory, which can store information over decades, consists of the conscious explicit and the unconscious implicit memory. Explicit memory, also known as declarative, can be subdivided into semantic and episodic memory. Procedural memory and priming effects are components of the implicit memory. ![](Brainlobes.svg "Brainlobes.svg") Brain regions: Brain regions Memory ------------------------------------------------------------- -------------------------------------- Frontal lobe, parietal lobe, dorsolateral prefrontal cortex Short-term Memory/ Working Memory Hippocampus Short-term Memory → Long-term Memory Medial temporal lobe (neocortex) Declarative Memory Amygdala, Cerebellum Procedural Memory For detailed information see chapter Memory ### Language Language is an essential system for communication which highly influences our life. This system uses sounds, symbols and gestures for the purpose of communication. Visual and auditory systems of a human body are the entrance-pathway for language to enter the brain. The motor system is responsible for speech and writing production, it serves as exit-pathway for language. The nature of language exists in the brain processes between the sensory and motor systems, especially between visual or auditory income and written or spoken outcome. The biggest part of the knowledge about brain mechanism for language is deduced from studies of language deficits resulting from brain damage. Even if there are about 10 000 different languages and dialects in the world, all of them express the subtleties of human experience and emotion. For detailed information see chapters Comprehension and Neuroscience of Comprehension ## Acquisition of language A phenomenon which occurs daily and in everybody's life is the acquisition of language. Anyhow scientists are not yet able to explain the underlying processes in detail or to define the point when language acquisition commences, even if they agree that it happens long before the first word is spoken.\ Theorists like Catherine Snow and Michael Tomasello think that the acquisition of language skills begins at birth. Others claim, it already commences in the womb. Newborns are not able to speak, even if babbling activates the brain regions later involved in speech production.\ The ability to understand the meaning of words already begins before the first birthday, even if they cannot be pronounced till then. The phonological representation of words in the memory changes between the stage of repetitive syllable-babbling and the one-word stage. At first children associate words with concrete objects, followed by an extension to the class of objects. After a period of overgeneralisation the children's system of concept approaches to the adults' one. To prove the assumption of understanding the meaning of words that early, researches at MIT let children watch two video clips of "Sesame Street". Simultaneously the children heard the sentences "Cookie Monster is tickling Big Bird" or "Big Bird is tickling Cookie Monster". The babies consistently looked more at the video corresponding to the sentence, what is an evidence for comprehension of more complex sentences, than they are able to produce during the one-word period.\ The different stages of speech production are listed in the table below. +--------------------+-----------------------+-----------------------+ \| Age \| Stage of Acquisition \| Example \| +====================+=======================+=======================+ \| 6th month \| Stage of babbling:\ \| \| \| \| - systematic \| \| \| \| combining of vowels \| \| \| \| and consonants \| \| +--------------------+-----------------------+-----------------------+ \| 7th -- 10th month \| Stage of repetitive \| da, ma, ga \| \| \| syllable-babbling:\ \| \| \| \| - higher part of \| ------------------- \| \| \| consonants → paired \| \| \| \| with a vowel -- \| mama, dada, gaga \| \| \| monosyllabic \| \| \| \| \| \| \| \| ------------------- \| \| \| \| \| \| \| \| reduplicated babbling \| \| +--------------------+-----------------------+-----------------------+ \| 11th -- 12th month \| Stage of variegated \| bada, dadu \| \| \| babbling:\ \| \| \| \| - combination of \| \| \| \| different consonants \| \| \| \| and vowels \| \| +--------------------+-----------------------+-----------------------+ \| 12th month \| Usage of first \| car, hat \| \| \| words - John \| \| \| \| Locke(1995):\ \| \| \| \| - prephonological → \| \| \| \| conson \| \| \| \| ant-vowel(-consonant) \| \| +--------------------+-----------------------+-----------------------+ Locke's theory about the usage of the first word is only a general tendency. Other researchers like Charlotte Bühler (1928), a German psychologist, think that the age of speaking the first word is around the tenth month, whereas Elizabeth Bates et al. (1992) proposed a period between eleven and 13 months. The one-word stage described above can last from two till ten months. Until the second year of life a vocabulary of about 50 words evolves, four times more than the child utilises. Two thirds of the language processed is still babbling. After this stage of learning the vocabulary increases rapidly. The so called vocabulary spurt causes an increment of about one word every two hours. From now on children learn to have fluent conversations with a simple grammar containing errors. As you can see in the following example, the length of the sentences and the grammatical output changes a lot. While raising his son, Knut keeps a tally of his son's speech production, to see how fast the language develops: Speech diary of Knut's son Andy:\ (Year; Month)\ 2;3: Play checkers. Big drum. I got horn. A bunny rabbit walk.\ 2;4: See marching bear go? Screw part machine. That busy bulldozer truck.\ 2;5: Now put boots on. Where wrench go? Mommy talking bout lady. What that paper clip doing?\ 2;6: Write a piece a paper. What that egg doing? I lost a shoe. No, I don\'t want to sit seat.\ 2;7: Where piece a paper go? Ursula has a boot on. Going to see kitten. Put the cigarette down. Dropped a rubber band. Shadow has hat just like that. Rintintin don\'t fly, Mommy.\ 2;8: Let me get down with the boots on. Don\'t be afraid a horses. How tiger be so healthy and fly like kite? Joshua throw like a penguin.\ 2;9: Where Mommy keep her pocket book? Show you something funny. Just like turtle make mud pie.\ 2;10: Look at that train Ursula brought. I simply don\'t want put in chair. You don\'t have paper. Do you want little bit, Cromer? I can\'t wear it tomorrow.\ 2;11: That birdie hopping by Missouri in bag? Do want some pie on your face? Why you mixing baby chocolate? I finish drinking all up down my throat. I said why not you coming in? Look at that piece a paper and tell it. We going turn light on so you can\'t see.\ 3;0: I going come in fourteen minutes. I going wear that to wedding. I see what happens. I have to save them now. Those are not strong mens. They are going sleep in wintertime. You dress me up like a baby elephant.\ 3;1: I like to play with something else. You know how to put it back together. I gon\' make it like a rocket to blast off with. I put another one on the floor. You went to Boston University? You want to give me some carrots and some beans? Press the button and catch it, sir. I want some other peanuts. Why you put the pacifier in his mouth? Doggies like to climb up.\ 3;2: So it can\'t be cleaned? I broke my racing car. Do you know the light wents off? What happened to the bridge? When it\'s got a flat tire it\'s need a go to the station. I dream sometimes. I\'m going to mail this so the letter can\'t come off. I want to have some espresso. The sun is not too bright. Can I have some sugar? Can I put my head in the mailbox so the mailman can know where I are and put me in the mailbox? Can I keep the screwdriver just like a carpenter keep the screwdriver? [^2] Obviously children are able to conjugate verbs and to decline nouns using regular rules. To produce irregular forms is more difficult, because they have to be learnt and stored in Long-term memory one by one. Rather than the repetition of words, the observation of speech is important to acquire grammatical skills. Around the third birthday the complexity of language increases exponentially and reaches a rate of about 1000 syntactic types.\ Another interesting field concerning the correlation between Memory and Language is Multilingualism. Thinking about children educated bilingual, the question arises how the two languages are separated or combined in the brain. Scientists assume that especially lexical information is stored independently for each language; the semantic and syntactic levels rather could be unified. Experiments have shown that bilinguals have a more capacious span of memory when they listen to words not only in one but in both languages. ## Disorders and Malfunctions Reading about the disorders concerning memory and language one might possibly think about amnesia or aphasia, both common diseases in the concerned brain regions. But when dealing with the correlation of memory and language we want to introduce only diseases which affect loss of memory as well as loss of language. ### Alzheimer\'s Disease Discovered in 1906 by Alois Alzheimer, this disease is the most common type of dementia. Alzheimer's is characterised by symptoms like loss of memory, loss of language skills and impairments in skilled movements. Additionally, other cognitive functions such as planning or decision-making which are connected to the frontal and temporal lobe can be reduced. The correlation between memory and language in this context is very important because they work together in order to establish conversations. When both are impaired, communication becomes a difficult task. People with Alzheimer's have reduced working memory capability, so they cannot keep in mind all of the information they heard during a conversation. They also forget words which they need to denote items, their desires and to understand what they are told. Affected persons also change their behaviour; they become anxious, suspicious or restless and they may have delusions or hallucinations. In the early stages of the disorder, sick persons become less energetic or suffer little loss of memory. But they are still able to dress themselves, to eat and to communicate. Middle stages of the disease are characterised by problems of navigation and orientation. They do not find their way home or even forget where they live. In the late stages of the disease, the patients' ability to speak, read and write decreases enormously. They are no longer able to denote objects and to talk about their feelings and desires. So their family and the nursing staff have great problems to find out what the patients want to tell them. In the end-state, the sick persons do not show any response or reaction. They lie in bed, have to be fed and are totally helpless. Most of them die after four to six years after diagnosis, although the disease can endure from three to twenty years. A cause for this is the difficulty to distinguish Alzheimer's from other related disorders. Only after death when seeing the shrinkage of the brain one can definitely say that the person was affected by Alzheimer's disease. \"Genetic Science Learning Center, University of Utah, <http://learn.genetics.utah.edu/> A comparison of the two brains:\ In the Alzheimer brain:\ · The cortex shrivels up, damaging areas involved in thinking, planning and remembering.\ · Shrinkage is especially severe in the hippocampus, an area of the cortex that plays a key role in formation of new memories.\ · Ventricles (fluid-filled spaces within the brain) grow larger. Scientists say that long before the first symptoms appear nerve cells that store and retrieve information have already begun to degenerate. There are two theories giving an explanation for the causes of Alzheimer's disease. The first describes plaques as protein fragments which defect the connection between nerve cells. They arise when little fragments release from nerve cell walls and associate with other fragments from outside the cell. These combined fragments, called plaques, append to the outside of nerve cells and destroy the connections. Then the nerve cells start to die because they are no longer provided with nutrients. As a conclusion the stimuli are no longer transferred. The second theory explains that tangles limit the functions of nerve cells. They are twisted fibers of another protein that form inside brain cells and destroy the vital cell transport made of proteins. But scientists have not yet found out the exact role of plaques and tangles. \"Genetic Science Learning Center, University of Utah, <http://learn.genetics.utah.edu/>\ - Alzheimer tissue has many fewer nerve cells and synapses than a healthy brain.\ - Plaques, abnormal clusters of protein fragments, build up between nerve cells.\ Dead and dying nerve cells contain tangles, which are made up of twisted fibers of another protein. Alzheimer's progress is separated into three stages: In the early stages (1), tangles and plaques begin to evolve in brain areas where learning, memory, thinking and planning takes place. This may begin 20 years before diagnosis. In the middle stages (2), plaques and tangles start to spread to areas of speaking and understanding speech. Also the sense of where your body is in relation to objects around you is reduced. This may last from 2--10 years. In advanced Alzheimer's disease (3), most of the cortex is damaged, so that the brain starts to shrink seriously and cells begin to die. The people lose their ability to speak and communicate and they do not recognise their family or people they know. This stage may generally last from one to five years. Today, more than 18 million people suffer from Alzheimer's disease, in Germany there are nearly 800,000 people. The number of affected persons increases enormously. Alzheimer's is often only related to old people. Five percent of the people older than 65 years and fifteen to twenty percent of the people older than 80 years suffer from Alzheimer's. But also people in the late thirties and forties can be affected by this heritable disease. The probability to suffer from Alzheimer's when parents have the typicall old-generation-Alzheimer's is not very high. ### Autism Autism is a neurodevelopment condition, which causes neurodevelopmental disorders in several fields. For the last decade, autism has been studied in light of Autistic Spectrum Disorders, including mild and severe autism, as well as Asperger\'s syndrome. Individuals with autism, for example, have restricted perception and problems in information processing. The often associated intellectual giftedness only holds for a minority of people with autism, whereas the majority possesses a normal amount of intelligence or is below the average.\ There are different types of autism, i.a.: - Asperger's syndrome -- usually arising at the age of three - infantile autism -- arising between nine and eleven months after birth The latter is important because it shows the correlation between memory and language in the children\'s behaviour very clearly. Two different types of infantile autism are the low functioning autism (LFA) and the high functioning autism (HFA). The LFA describes children with an IQ lower than 80, the HFA those with an IQ higher than 80. The disorders in both types are similar, but they are more strongly developed in children with LFA.\ The disorders are mainly defined by the following aspects: 1. the inability of normal social interaction, e.g. amicable relations to other children 2. the inability of ordinary communication, e.g. disorder of spoken language/idiosyncratic language 3. stereotypical behaviour, e.g. stereotypical and restricted interests with an atypical content To demonstrate the inability to manage normal communication and language, the University of Pittsburgh and the ESRC performed experiments to provide possible explanations. Sentences, stories or numbers were presented to children with autism and to normal children. The researchers concluded that the disorders in people with HFA and LFA are caused by an impairment in declarative memory. This impairment leads to difficulties in learning and remembering sentences, stories or personal events, whereas the ability to learn numbers is available. It has been shown that these children are not able to link words they heard to their general knowledge, thus the words are only partially learnt, with an idiosyncratic meaning. This explains why LFA and HFA affected children differ in their way of thinking from sane children. It is often difficult for them to understand others and vice versa. Furthermore scientists believe that the process of language learning depends on an initial vocabulary of fully meaningful words. It is assumed that these children do not possess such a vocabulary, thus their language development is impaired. In a few cases the acquisition of language fails completely, therefore in some cases the children are not able to use language in general. The inability of learning and using language can be a consequence of an impairment of declarative memory. It might also cause a low IQ because the process of learning is language-mediated. In HFA the IQ is not significantly lower than the IQ of sane children. This correlates well with their better understanding of word meanings. They have a milder form of autism. The experiments have also shown that adults do not have problems with the handling of language. A reason for that might be that they have been taught to use it during development or maybe they acquired this ability through reading and writing. The causes of autism are not yet explored appropriately to get some idea how to help and support those people having autism in everyday-life. It is still not clear whether the diseases are really caused by genetic disorders. It is also possible that other neurological malfunctions like brain damages or biochemical specialties are responsible for autism. The research just started to get answers to those questions.\ ## References and Resources ```{=html} <references/> ``` Books Steven Pinker: The Language Instinct; The Penguin Press, 1994, \ Gisela Klann-Delius: Spracherwerb; Sammlung Metzler, Bd 325; Verlag J.B.Metzler; Stuttgart, Weimar, 1999; \ Arnold Langenmayr: Sprachpsychologie - Ein Lehrbuch; Verlag für Psychologie, Hogrefe, 1997; \ Mark F. Bear, Barry W. Connors, Michael A. Paradiso: Neuroscience - Exploring The Brain; Lippincott Williams & Wilkins, 3rd edition, 2006; \ Links <http://de.wikipedia.org/wiki/Ged%C3%A4chtnis>\ <http://en.wikipedia.org/wiki/Memory>\ <http://www.cogsci.rpi.edu/CSJarchive/proceedings/2006/docs/p822.pdf>\ <http://www.psychology.uiowa.edu/faculty/gupta/pdf/gupta.brain+lang2003.pdf>\ <http://www.cogsci.rpi.edu/CSJarchive/1980v04/i03/p0243p0284/MAIN.PDF>\ <http://www.quarks.de/gedaechtnis/gedaechtnis.pdf>\ <http://www.alz.org/alzheimers_disease_alzheimers_disease.asp>\ <http://en.wikipedia.org/wiki/Autism>\ <http://www.apa.org/journals/releases/neu20121.pdf>\ <http://www.esrc.ac.uk/ESRCInfoCentre/Plain_English_Summaries/knowledge_communication_learning>\ /index22.aspx?ComponentId=17702&SourcePageId=11748\ [^1]: E. G. Goldstein, \"Cognitive Psychology - Connecting Mind, Research, and Everyday Experience\", page 137, THOMSON WADSWORTH TM 2005 [^2]: S. Pinker, The Language Instinct, p.269f
# Cognitive Psychology and Cognitive Neuroscience/Imagery +:------------------------------+:----:+------------------------------:+ \| Previous \| [O \| [Next \| \| C \| verv \| Chapter \| \| mory_and_Language "wikilink") \| niti \| \| \| \| ve_P \| \| \| \| sych \| \| \| \| olog \| \| \| \| y_an \| \| \| \| d_Co \| \| \| \| gnit \| \| \| \| ive_ \| \| \| \| Neur \| \| \| \| osci \| \| \| \| ence \| \| \| \| "wi \| \| \| \| kili \| \| \| \| nk") \| \| +-------------------------------+------+-------------------------------+ of issues concerning their copyright.** ## Introduction & History Mental imagery was already discussed by the early Greek philosophers. Socrates sketched a relation between perception and imagery by assuming that visual sensory experience creates images in the human\'s mind, which are representations of the real world. Later on, Aristoteles stated that \"thought is impossible without an image\". At the beginning of the 18th century, Bishop Berkeley proposed another role of mental images - similar to the ideas of Sokrates - in his theory of idealism. He assumed that our whole perception of the external world consists only of mental images. At the end of the 19th century, Wilhelm Wundt - the generally acknowledged founder of experimental psychology and cognitive psychology - called imagery, sensations and feelings the basic elements of consciousness. Furthermore, he had the idea that the study of imagery supports the study of cognition because thinking is often accompanied by images. This remark was taken up by some psychologists and gave rise to the imageless-thought debate, which discussed the same question Aristoteles already had asked: Is thought possible without imagery? In the early 20th century, when Behaviourism became the main stream of psychology, Watson argued that there is no visible evidence of images in human brains and therefore, the study of imagery is worthless. This general attitude towards the value of research on imagery did not change until the birth of cognitive psychology in the 1950s and -60s. Later on, imagery has often been believed to play a very large, even pivotal, role in both memory (Yates, 1966; Paivio, 1986) and motivation (McMahon, 1973). It is also commonly believed to be centrally involved in visuo-spatial reasoning and inventive or creative thought. ## Concept Imagination is the ability to form images, perceptions, and concepts. In fact, images, perceptions and concepts are not perceived through sight, hearing or other senses. Imagine the work of the mind and help create fantasy. Imagination helps to provide meaning and provide an understanding of knowledge; imagination is the basic ability of people to create meaning for the world; imagination also plays a key role in the learning process. The basic training method for cultivating imagination is to listen to stories; when listening to stories, the accuracy of wording is the basic factor of "generating the world". Imagine any power we face. We combine what we touch, see and hear into a \"picture\" by imagination. It is widely believed that as an intrinsic ability, as a factor in perceiving the public world from the senses, in the process of inventing a partial or complete personal domain in the mind, the term is used in the professional use of psychology, meaning the mind. In the recovery process, \[source request\] restores the sensory object previously presented to the perception. Because the use of this term contradicts the use of everyday language, some psychologists tend to describe this process as an \"image process\" or \"image\", or as a \"regeneration\" imaginary process, using \"generating or constructive\" The imaginary process \"images of imagination\" are seen with the \"eye of the soul.\" Imagination can also be expressed through fairy tales or imaginary situations. The most famous invention or entertainment product is created by one\'s imagination. One hypothesis about the evolutionary process of human imagination is that imagination allows conscious species to solve problems by using psychological simulations. Children are often considered to be imaginative groups. Because their way of thinking has not yet formed, there are fewer ideological restrictions and rules than adults. Therefore, it is often imaginative. Children often use stories or pretend games to practice their imagination. When children have fantasies, they play a role on two levels: on the first level, they use role-play to achieve what they create with imagination; at the second level, they pretend to believe that the situation is to play games. In terms of behavior, what they create seems to be a real reality, and this already exists in the myth of the story. Artists often need a lot of imagination because they are engaged in creative work, and imagination can help them break existing rules and bring aesthetics into a new model. Imagine the universal use of this term, which means the process of forming an image that has not been experienced before in the mind, or the process of forming an image that is at least partially experienced or formed by different combinations. Some typical examples are as follows: fairy tale Fiction The illusion of forms inspired by fantasy novels and science fiction spurs readers to pretend that these stories are real, and by resorting to fantasy objects such as books or fantasy, these objects are not in the fantasy world. Imagination in this sense (not limited to the precise knowledge gained from actual needs) is somewhat exempt from objective limitations. Imagine being in the position of another person. This ability is very important for social relationships and social understanding. Einstein said: \"Imagination\... is more important than knowledge. Knowledge is limited. Imagination encompasses the world.\" \[8\] However, in all fields, even imagination is limited: therefore, one Human imagination does violate the basic law, or the inevitable principle of violating the actual possibility, or the possibility of rationality in a certain situation, is considered a mental disorder. The same limitations place imagination in the realm of scientific assumptions. The advancement of scientific research is largely due to some temporary explanations; these explanations are based on imagination. However, these assumptions must be made up of previously identified facts and must be coordinated with the principles of a particular science. Imagination is an experimental part of thinking that creates functional-based theories and ideas. Separate objects from real perceptions and use complex \"features\" to envision creating new ideas or changing ideas. This part of the thinking is crucial to improving and improving the way new and old tasks are completed. These experimental ideas can be implemented steadily in the field of simulation; then, if the concept is very likely and its function is real, then the concept can be implemented in reality. Imagination is the key to the new development of the soul. It shares with others and progresses together. Imagination can be divided into: Automatic imagination (from dreams and daydreams) Don\'t automatically imagine (renewable imagination, creative imagination, future dreams) ## The Imagery Debate Imagine yourself back on vacation again. You are now walking along the beach, while projecting images of white benzene-molecules onto the horizon. At once you are realizing that there are two real little white dots under your projection. Curiously you are walking towards them, until your visual field is filled by two seriously looking, but fiercely debating scientists. As they take notice of your presence, they invite you to take a seat and listen to the still unsolved imagery debate. Today's imagery debate is mainly influenced by two opposing theories: On the one hand Zenon Pylyshyn's (left) propositional theory and on the other hand Stephen Kosslyn's (right) spatial representation theory of imagery processing. ### Theory of propositional representation The theory of Propositional Representation was founded by Dr. Zenon Pylyshyn who invented it in 1973. He described it as an epiphenomenon which accompanies the process of imagery, but is not part of it. Mental images do not show us how the mind works exactly. They only show us that something is happening. Just like the display of a compact disc player. There are flashing lights that display that something happens. We are also able to conclude what happens, but the display does not show us how the processes inside the compact disc player work. Even if the display would be broken, the compact disc player would still continue to play music. #### Representation The basic idea of the propositional representation is that relationships between objects are represented by symbols and not by spatial mental images of the scene. For example, a bottle under a table would be represented by a formula made of symbols like UNDER(BOTTLE,TABLE). The term proposition is lend from the domains of Logic and Linguistics and means the smallest possible entity of information. Each proposition can either be true or false. If there is a sentence like \"Debby donated a big amount of money to Greenpeace, an organisation which protects the environment\", it can be recapitulated by the propositions \"Debby donated money to Greenpeace\", \"The amount of money was big\" and \"Greenpeace protects the environment\". The truth value of the whole sentence depends on the truth values of its constituents. Hence, if one of the propositions is false, so is the whole sentence. #### Propositional networks This last model does not imply that a person remembers the sentence or its single propositions in its exact literal wording. It is rather assumed that the information is stored in the memory in a propositional network. !Figure 1: Example of a propositional network In Figure 1, each circle represents a single proposition. Regarding the fact that some components are connected to more than one proposition, they construct a network of propositions. Propositional networks can also have a hierarchy, if a single component of a proposition is not a single object, but a proposition itself. An example of a hierarchical propositional network describing the sentence \"John believes that Anna will pass her exam\" is illustrated in Figure 2. !Figure 2: Propositional network with hierarchy #### Complex objects and schemes Even complex objects can be generated and described by propositional representation. A complex object like a ship would consist of a structure of nodes which represent the ships properties and the relationship of these properties. Almost all humans have concepts of commonly known objects like ships or houses in their mind. These concepts are abstractions of complex propositional networks and are called schemes. For example our concept of a house includes propositions like: `Houses have rooms.`\ `Houses can be made from wood.`\ `Houses have walls.`\ `Houses have windows.`\ `...` Listing all of these propositions does not show the structure of relationships between these propositions. Instead, a concept of something can be arranged in a schema consisting of a list of attributes and values, which describe the properties of the object. Attributes describe possible forms of categorisation, while values rep- resent the actual value for each attribute. The schema-representation of a house looks like this: `House`\ `Category: building`\ `Material: stone, wood `\ `Contains: rooms`\ `Function: shelter for humans`\ `Shape: rectangular`\ `...` The hierarchical structure of schemes is organised in categories. For example, \"house\" belongs to the category \"building\" (which has of course its own schema) and contains all attributes and values of the parent schema plus its own specific values and attributes. This way of organising objects in our environment into hierarchical models enables us to recognise objects we have never seen before in our life, because they can possibly be related to categories we already know. #### Experimental support In an experiment performed by Wisemann und Neissner in 1974, people are shown a picture which, on first sight, seems to consist of random black and white shapes. After some time the subjects realise that there is a dalmatian dog in it. The results of this show that people who recognise the dog remember the picture better than people who do not recognise him. An possible explanation is that the picture is stored in the memory not as a picture, but as a proposition. In an experiment by Weisberg in 1969, subjects had to memorise sentences like \"Children who are slow eat bread that is cold\". Then the subjects were asked to associate the first word from the sentence that comes in their mind to a word given by the experiment conductor. Almost all subjects associated the word \"children\" to the given word \"slow\", although the word \"bread\" has a position that is more close to the given word \"slow\" than the word \"children\". An explanation for this is that the sentence is stored in the memory using the three propositions \"Children are slow\", \"Children eat bread\" and \"Bread is cold\". The subjects associated the word \"children\" with the given word \"slow\", because both belong to one proposition, while \"bread\" and \"slow\" belong to different ones. The same evidence was proven in another experiment by Ratcliff and McKoon in 1978. ### Theory of spatial representation Stephen Kosslyn\'s theory opposing Pylyshyn\'s propositional approach implies that images are not only represented by propositions. He tried to find evidence for a spatial representation system that constructs mental, analogous, three-dimensional models. The primary role of this system is to organize spatial information in a general form that can be accessed by either perceptual or linguistic mechanisms. It also provides coordinate frameworks to describe object locations, thus creating a model of a perceived or described environment. The advantage of a coordinate representation is that it is directly analogous to the structure of real space and captures all possible relations between objects encoded in the coordinate space. These frameworks also reflect differences in the salience of objects and locations consistent with the properties of the environment, as well as the ways in which people interact with it. Thus, the representations created are models of physical and functional aspects of the environment. #### Encoding What, then, can be said about the primary components of cognitive spatial representation? Certainly, the distinction between the external world and our internal view of it is essential, and it is helpful to explore the relationship between the two further from a process-oriented perspective. The classical approach assumes a complex internal representation in the mind that is constructed through a series of specific perceived stimuli, and that these stimuli generate specific internal responses. Research dealing specifically with geographic-scale space has worked from the perspective that the macro-scale physical environment is extremely complex and essentially beyond the control of the individual. This research, such as that of Lynch and of Golledge (1987) and his colleagues, has shown that there is a complex of behavioural responses generated from corresponding complex external stimuli, which are themselves interrelated. Moreover, the results of this research offers a view of our geographic knowledge as a highly interrelated external/internal system. Using landmarks encountered within the external landscape as navigational cues is the clearest example of this interrelationship. The rationale is as follows: We gain information about our external environment from different kinds of perceptual experience; by navigating through and interacting directly with geographic space as well as by reading maps, through language, photographs and other communication media. Within all of these different types of experience, we encounter elements within the external world that act as symbols. These symbols, whether a landmark within the real landscape, a word or phrase, a line on a map or a building in a photograph, trigger our internal knowledge representation and generate appropriate responses. In other words, elements that we encounter within our environment act as external knowledge stores. !Figure 3: Internal representation map{width="350"} Each external symbol has meaning that is acquired through the sum of the individual perceiver\'s previous experience. That meaning is imparted by both the specific cultural context of that individual and by the specific meaning intended by the generator of that symbol. Of course, there are many elements within the natural environment not \"generated\" by anyone, but that nevertheless are imparted with very powerful meaning by cultures (e.g., the sun, moon and stars). Man-made elements within the environment, including elements such as buildings, are often specifically designed to act as symbols as at least part of their function. The sheer size of downtown office buildings, the pillars of a bank facade and church spires pointing skyward are designed to evoke an impression of power, stability or holiness, respectively. These external symbols are themselves interrelated, and specific groupings of symbols may constitute self-contained external models of geographic space. Maps and landscape photographs are certainly clear examples of this. Elements of differing form (e.g., maps and text) can also be interrelated. These various external models of geographic space correspond to external memory. From the perspective just described, the total sum of any individual\'s knowledge is contained in a multiplicity of internal and external representations that function as a single, interactive whole. The representation as a whole can therefore be characterised as a synergistic, self-organising and highly dynamic network. #### Experimental support ##### Interaction Early experiments on imagery were already done in 1910 by Perky. He tried to find out, if there is any interaction between imagery and perception by a simple mechanism. Some subjects are told to project an image of common objects like a ship onto a wall. Without their knowledge there is a back projection, which subtly shines through the wall. Then they have to describe this picture, or are questioned about for example the orientation or the colour of the ship. In Perkys experiment, none of the 20 subjects recognised that the description of the picture did not arise from their mind, but were completely influenced by the picture shown to them. ##### Image Scanning Another seminal research in this field were Kosslyn\'s image-scanning experiments in the 1970s. Referring to the example of the mental representation of a ship, he experienced another linearity within the move of the mental focus from one part of the ship to another. The reaction time of the subjects increased with distance between the two parts, which indicates, that we actually create a mental picture of scenes while trying to solve small cognitive tasks. Interestingly, this visual ability can be observed also with congenitally blind, as Marmor and Zaback (1976) found out. Presuming, that the underlying processes are the same of sighted subjects, it could be concluded that there is a deeper encoded system that has access to more than the visual input. ##### Mental Rotation Task Other advocates of the spatial representation theory, Shepard and Metzler, developed the mental rotation task in 1971. Two objects are presented to a participant in different angles and his job is to decide whether the objects are identical or not. The results show that the reaction times increases linearly with the rotation angle of the objects. The participants mentally rotate the objects in order to match the objects to one another. This process is called \"mental chronometry\". Together with Paivio\'s memory research, this experiment was crucial for the importance of imagery within cognitive psychology, because it showed the similarity of imagery to the processes of perception. For a mental rotation of 40° the subjects needed two seconds in average, whereas for a 140° rotation the reaction time increased to four seconds. Therefore, it can be concluded that people in general have a mental object rotation rate of 50° per second. ##### Spatial Frameworks Although most research on mental models has focussed on text comprehension, researchers generally believe that mental models are perceptually based. Indeed, people have been found to use spatial frameworks like those created for texts to retrieve spatial information about observed scenes (Bryant, 1991). Thus, people create the same sorts of spatial memory representations no matter if they read about an environment or see it themselves. ##### Size and the visual field If an object is observed from different distances, it is harder to perceive details if the object is far away because the objects fill only a small part of the visual field. Kosslyn made an experiment in 1973 in which he wanted to find out if this is also true for mental images, to show the similarity of the spatial representation and the perception of real environment. He told participants to imagine objects which are far away and objects which are near. After asking the participants about details, he supposed that details can be observed better if the object is near and fills the visual field. He also told the participants to imagine animals with different sizes near by another. For example an elephant and a rabbit. The elephant filled much more of the visual field than the rabbit and it turned out that the participants were able to answer questions about the elephant more rapidly than about the rabbit. After that the participants had to imagine the small animal besides an even smaller animal, like a fly. This time, the rabbit filled the bigger part of the visual field and again, questions about the bigger animal were answered faster. The result of Kosslyn\'s experiments is that people can observe more details of an object if it fills a bigger part of their mental visual field. This provides evidence that mental images are represented spatial. ### Discussion Since the 1970s, many experiments enriched the knowledge about imagery and memory to a great extend in the course of the two opposing point of views of the imagery debate. The seesaw of assumed support was marked of lots of smart ideas. The following section is an example of the potential of such controversities. In 1978, Kossylyn expanded his image screening experiment from objects to real distances represented on maps. In the picture you see our island with all the places you encountered in this chapter. Try to imagine, how far away from each other they are. This is exactly the experiment performed by Kossylyn. Again, he predicted successfully a linear dependency between reaction time and spatial distance to support his model. !Figure 5: Support for Kosslyn\'s theory of spatial representation{width="400"} In the same year, Pylyshyn answered with what is called the \"tacit-knowledge explanation\", because he supposed that the participants include knowledge about the world without noticing it. The map is decomposed into nodes with edges in between. The increase of time, he thought, was caused by the different quantity of nodes visited until the goal node is reached. !Figure 6: Support for Pylyhsyn\'s theory of propositional representation{width="400"} Only four years later, Finke and Pinker published a counter model. Picture (1) shows a surface with four dots, which were presented to the subjects. After two seconds, it was replaced by picture (2), with an arrow on it. The subjects had to decide, if the arrow pointed at a former dot. The result was, that they reacted slower, if the arrow was farer away from a dot. Finke and Pinker concluded, that within two seconds, the distances can only be stored within a spatial representation of the surface. !Figure 7: Counter model by Finke and Pinker{width="400"} To sum it up, it is commonly believed, that imagery and perception share certain features but also differs in some points. For example, perception is a bottom-up process that originates with an image on the retina, whereas imagery is a top-down mechanism which originates when activity is generated in higher visual centres without an actual stimulus. Another distinction can be made by saying that perception occurs automatically and remains relatively stable, whereas imagery needs effort and is fragile. But as psychological discussions failed to point out one right theory, now the debate is translocated to neuroscience, which methods had promising improvements throughout the last three decades. ## Neuropsychological approach ### Investigating the brain - a way to resolve the imagery debate? Visual imagery was investigated by psychological studies relying solely on behavioural experiments until the late 1980s. By that time, research on the brain by electrophysiological measurements such as the event-related potential (ERP) and brain-imaging techniques (fMRI, PET) became possible. It was therefore hoped that neurological evidence how the brain responds to visual imagery would help to resolve the imagery debate. We will see that many results from neuroscience support the theory that imagery and perception are closely connected and share the same physiological mechanisms. Nevertheless the contradictory phenomena of double dissociations between imagery and perception shows that the overlap is not perfect. A theory that tries to take into account all the neuropsychological results and gives an explanation for the dissociations will therefore be presented in the end of this section. ### Support for shared physiological mechanisms of imagery and perception Brain imaging experiments in the 1990s confirmed the results which previous electrophysiological measurements had already made. Therein brain activity of participants was measured, using either PET or fMRI, both when they were creating visual images and when they were not creating images. These experiments showed that imagery creates activity in the striate cortex which is, being the primary visual receiving area, also active during visual perception. Figure 8 (not included yet due to copyright issues) shows how activity in the striate cortex increased both when a person perceived an object ("stimulus on") and when the person created a visual image of it ("imagined stimulus"). Although the striate cortex has not become activated by imagery in all brain-imaging studies, most results indicate that it is activated when participants are asked to create detailed images. Another approach to understand imagery has been made by studies of people with brain damage in order to determine if both imagery and perception are affected in the same way. Often, patients with perceptual problems also have problems in creating images like in the case of people having both lost the ability to see colour and to create colours through imagery. Another example is that of a patient with unilateral neglect, which is due to damage to the parietal lobes and causes that the patient ignores objects in one half of his visual field. By asking the patient to imagine himself standing at a place that is familiar to him and to describe the things he is seeing, it was found out that he did not only neglect the left side of his perceptions but also the left side of his mental images, as he could only name objects that were on the right hand side of his mental image. The idea that mental imagery and perception share physiological mechanisms is thus supported by both brain imaging experiments with normal participants and effects of brain damage like in patients with unilateral neglect. However, also contradictory results have been observed, indicating that the underlying mechanisms of perception and imagery cannot be identical. ### Double dissociation between imagery and perception A double dissociation exists when a single dissociation (one function is present another is absent) can be demonstrated in one person and the complementary type of single dissociation can be demonstrated in another person. Regarding imagery and perception a double dissociation has been observed as there are both patients with normal perception but impaired imagery and patients with impaired perception but normal imagery. Accordingly, one patient with damage to his occipital and parietal lobes was able to recognise objects and draw accurate pictures of objects placed before him, but was unable to draw pictures from memory, which requires imagery. Contrary, another patient suffering from visual agnosia was unable to identify pictures of objects even though he could recognise parts of them. For example, he did not recognise a picture of an asparagus but labelled it as "rose twig with thorns". On the other hand, he was able to draw very detailed pictures from memory which is a task depending on imagery. As double dissociation usually suggests that two functions rely on different brain regions or physiological mechanisms, the described examples imply that imagery and perception do not share exactly the same physiological mechanisms. This of course conflicts with the evidence from brain imaging measurements and other cases of patients with brain damage mentioned above that showed a close connection between imagery and perception. ### Interpretation of the neuropsychological results A possible explanation for the paradox that on the one hand there is great evidence for parallels between perception and imagery but on the other hand the observed double dissociation conflicts with these results goes as follows. Mechanisms of imagery and perception overlap only partially so that the mechanisms responsible for imagery are mainly located in higher visual centres and the mechanisms underlying perception are located at both lower and higher centres (Figure 9, not included yet due to copyright issues). Accordingly, perception is thought to constitute a bottom-up-process that starts with an image in the retina and involves processing in the retina, the Lateral Geniculate Nucleus, the striate cortex and higher cortical areas. In contrast, imagery is said to start as a top-down process, as its activity is generated in higher visual centres without any actual stimulus, that is without an image on the retina. This theory provides explanations for both the patient with impaired perception but normal imagery and the patient with normal perception but impaired imagery. In the first case, the patient's perceptual problems could be explained by damage to early processing in the cortex and his ability to still create images by the intactness of higher areas of the brain. Similarly, in the latter case, the patient\'s impaired imagery could be caused by damage to higher-level areas whereas the lower centres could still be intact. Even though this explanation fits several cases it does not fit all cases. Consequently, further research has to accomplish the task of developing an explanation that is able to explain the relation between perception and imagery sufficiently. ## Imagery and memory Besides the imagery debate, which is concerned with the question how we imagine for example objects, persons, situations and involve our senses in these mental pictures, questions concerning the memory are still untreated. In this part of the chapter about imagery we are dealing with the questions how images are encoded in the brain, and how they are recalled out of our memory. In search of answering these questions three major theories evolved. All of them explain the encoding and recalling processes different, and as usual validating experiments were realised for all these theories. In search of answering these questions, three major streams evolved. All of them try to explain the encoding and recalling processes differently and, as usual, validating experiments were realised in all streams. ### The common-code theory This view of memory and recall theories that images and words access semantic information in a single conceptual system that is neither word-like nor spatial-like. The model of common-code hypothesis that for example images and words both require analogous processing before accessing semantic information. So the semantic information of all sensational input is encoded in the same way. The consequence is that when you remember for example a situation where you were watching an apple falling down a tree, the visual information about the falling of the apple and the information about the sound, which appeared when the apple hit the ground, both are constructed on -- the -- fly in the specific brain regions (e.g. visual images in the visual cortex) out of one code stored in the brain. Another difference of this model is that it claims images require less time than words for accessing the common conceptual system. Therefore images need less time to be discriminated, because they share a smaller set of possible alternatives than words. Apart from that words have to be picked out of a much larger set of ambiguous possibilities in the mental dictionary. The heaviest point of criticism on this model is that it does not declare where this common code is stored at the end. ### The abstract-propositional theory This theory rejects any notion of the distinction between verbal and non - verbal modes of representation, but instead describes representations of experience or knowledge in terms of an abstract set of relations and states, in other words propositions. This theory postulates that the recall of images is better if the one who is recalling the image has some connection to the meaning of the image which is recalled. For example if you are looking at an abstract picture on which a bunch of lines is drawn, which you cannot combine in a meaningful way with each other, the recall process of this picture will be very hard (if not impossible). As reason for this it is assumed, that there is no connection to propositions, which can describe some part of the picture, and no connection to a propositional network, which reconstructs parts of the picture. The other case is, that you look at a picture with some lines in it, which you can combine in a meaningful way with each other. The recall process should be successful, because in this case you can scan for a proposition which has at least one attribute with the meaning of the image you recognised. Then this proposition returns the information which is necessary to recall it. ### The dual-code theory Unlike the common-code and abstract-propositional approaches, this model postulates that words and images are represented in functionally distinct verbal and non - verbal memory systems. To establish this model, Roland and Fridberg (1985) had run an experiment, in which the subjects had either to imagine a mnemonic or how they walk the way to their home through their neighbourhoods. While the subjects did one of this tasks, their brain was scanned with the positron emission tomography (PET). Figure 10 is a picture combining the brains of the subjects, which achieved the first and the second task. !Figure 10: Green dots represent regions which showed a higher activity during the walking home task; yellow dots represent regions which showed a higher activity during the mnemonic task. As we can see on the picture, for the processing of verbal and spatial information different brain areas are involved. The brain areas, which were active during the walking home task, are the same areas which are active during the visual perception and the information processing. And among those areas which showed activity while the mnemonic task was carried out, the Broca-centre is included, where normally language processing is located. This can be considered as an evidence for both representation types to be somehow connected with the modalities, as Paivio's theory about dual-coding suggests Anderson (1996). Can you imagine other examples, which argue for the dual-code theory? For example, you walk along the beach in the evening, there are some beach bars ahead. You order a drink, and next to you, you see a person, which seems to be familiar to you. While you drink your drink, you try to remember the name of this person, but you fail stranded, even if you can remember where you have seen the person the last time, and perhaps what you have talked about in that situation. Now imagine another situation. You walk through the city, and you pass some coffee bars, out of one of them you hear a song. You are sure that you know that song, but you cannot remember the name of the interpreter, nor the name of the song either where you have heard it. Both examples can be interpreted as indicators for the assumption that in these situations you can recall the information which you perceived in the past, but you fail in remembering the propositions you connected to them. !Figure 11: An abstract picture vs. a smiling Knut with a baseball cap In this area of research, there are of course other unanswered questions, for example why we cannot imagine smell, how the recall processes are performed or where the storage of images is located. The imagery debate is still going on, and ultimate evidence showing which of the models explains the connection between imagery and memory are missing. For now the dual-code theory seems to be the most promising model. ## References Anderson, John R. (1996). Kognitive Psychlogie: eine Einfuehrung. Heidelberg: Spektrum Akademischer Verlag. Bryant, D. J., B. Tversky, et al. (1992). "Internal and External Spatial Frameworks for Representing Described Scenes." Journal of Memory and Language 31: 74-98. Coucelis, H., Golledge, R., and Tobler, W. (1987). Exploring the anchor- point hypothesis of spatial cognition. Journal of Environmental Psychol- ogy, 7, 99-122. E.Bruce Goldstein, Cognitive Psychology, Connecting Mind, Research, and Everyday Experience (2005) - . Marmor, G.S. and Zaback, L.A. (1976). Mental Rotation in the blind: Does mental rotation depend on visual imagery?. Journal of Experimental Psychology: Human Perception and Performance, 2, 515-521. Roland, P. E. & Fridberg, L. (1985). Localization of critical areas activated by thinking. Journal of Neurophysiology, 53, 1219 -- 1243. Paivio, A. (1986). Mental representation: A dual-coding approach. New York: Oxford University Press. ## Links & Further Reading Cognitive Psychology Osnabrueck Dr. Rolf A. Zwaan\'s Homepage with many Papers Articles Cherney, Leora (2001): Right Hemisphere Brain Damage Grodzinsky, Yosef (2000): The neurology of syntax: Language use without Broca's area. Mueller, H. M., King, J. W. & Kutas, M. (1997). Event-related potentials elicited by spoken relative clauses; Cognitive Brain Research 4:193-203. Mueller, H.M. & Kutas, M. (1996). What's in a name? Electrophysiological differences between spoken nouns, proper names and one's own name; NeuroReport 8:221-225. Revised in July 2007 by: Alexander Blum (Spatial Representation, Discussion of the Imagery Debate, Images), Daniel Elport (Propositional Representation), Alexander Lelais (Imagery and Memory), Sarah Mueller (Neuropsychological approach), Michael Rausch (Introduction, Publishing) Authors of the first version (2006): Wendy Wilutzky, Till Becker, Patrick Ehrenbrink (Propositional Representation), Mayumi Koguchi, Da Shengh Zhang (Spatial Representation, Intro, Debate).
# Cognitive Psychology and Cognitive Neuroscience/Comprehension : \"Language is the way we interact and communicate, so, naturally, the means of communication and the conceptual background that's behind it, which is more important, are used to try to shape attitudes and opinions and induce conformity and subordination. Not surprisingly, it was created in the more democratic societies.\" - Noam Chomsky Language is a central part of everyday life and communication a natural human necessity. For those reasons, there has been a high interest in their properties. However, describing the processes of language turns out to be quite hard. We can define language as a system of communication through which we code and express our feelings, thoughts, ideas and experiences. Already Plato was concerned with the nature of language in his dialogue "Cratylus", where he discussed first ideas about nowadays important principles of linguistics namely morphology and phonology. Gradually philosophers, natural scientists and psychologists became interested in features of language. Since the emergence of the cognitive science in the 1950\'s and Chomsky´s criticism on the behaviourist view, language is seen as a cognitive ability of humans, thus incorporating linguistics in other major fields like computer science and psychology. Today, psycho-linguistics is a discipline on its own and its most important topics are acquisition, production and comprehension of language. Especially in the 20th century, many studies concerning communication have been conducted, evoking new views on old facts. New techniques, like CT, MRI and fMRI or EEG, as described in Methods of Behavioural and Neuroscience Methods, made it possible to observe brain during communication processes in detail. Later on, an overview of the most popular experiments and observed effects is presented. But in order to understand those, one needs to have a basic idea of semantics and syntax as well as of linguistic principles for processing words, sentences and full texts. Finally, some questions will arise: How is language affected by culture? Or in philosophical terms, the discussion about the relationship between language and thoughts has to be developed. ## Historical review on Psycholinguistics & Neurolinguistics Starting with philosophical approaches, the nature of the human language had ever been a topic of interest. Galileo in the 16th century saw the human language as the most important invention of humans. Later on in the 18th century the scientific study of language began by psychologists. Wilhelm Wundt (founder of the first laboratory of psychology) saw language as the mechanism by which thoughts are transformed into sentences. The observations of Wernike and Broca (see chapter 9) were milestones in the studies of language as a cognitive ability. In the early 1900s the behaviouristic view influenced the study of language very much. In 1957 B.F.Skiner published his book \"Verbal Behaviour\", in which he proposed that learning of language can be seen as a mechanism of reinforcement. Noam Chomsky (quoted at the beginning of this chapter) published in the same year \"Syntactic Structures\". He proposed that the ability to invent language is somehow coded in the genes. That led him to the idea that the underlying basis of language is similar across cultures. There might be some kind of universal grammar as a base, independent of what kind of language (including sign language) might be used by humans. Further on Chomsky published a review of Skinner´s \"Verbal Behaviour\" in which he presented arguments against the behaviouristic view. There are still some scientists who are convinced that it does not need a mentalist approach like Chomsky proposed, but in the meantime most agree that human language has to be seen as a cognitive ability. \[edit\] Current goals of Psycholinguistics A natural language can be analysed at a number of different levels. In linguistics we differ between phonology (sounds), morphology (words), syntax (sentence structure), semantics (meaning), and pragmatics (use). Linguists try to find systematic descriptions capturing the regularities inherent in the language itself. But a description of natural language just as a abstract structured system, can not be enough. Psycholinguists rather ask, how the knowledge of language is represented in the brain, and how it is used. Today\'s most important research topics are: 1. comprehension: How humans understand spoken as well as written language, how language is processed and what interactions with memory are involved. 2. speech production: Both the physical aspect of speech production, and the mental process that stands behind the uttering of a sentence. 3. acquisition: How people learn to speak and understand a language. ## Characteristic features What is a language? What kinds of languages do exist? Are there characteristic features that are unique in human language? There are plenty of approaches how to describe languages. Especially in computational linguistics, researchers try to find formal definitions for different kinds of languages. But for psychology other aspects of language than its function as pure system of communication are of central interest. Language is also a tool we use for social interactions starting with the exchange of news up to the identification of social groups by their dialect. We use it for expressing our feelings, thoughts, ideas etc. Although there are plenty ways to communicate (consider Non-Human-Language) humans expect their system of communication - the human language to be unique. But what is it that makes the human language so special and unique? Four major criteria have been proposed by Professor Franz Schmalhofer from the University of Osnabrück as explained below: - semanticity - displacement - creativity - structure dependency Semanticity means the usage of symbols. Symbols can either refer to objects or to relations between objects. In the human language words are the basic form of symbols. For example the word \"book\" refers to an object made of paper on which something might be written. A relation symbol is the verb \"to like\" which refers to the sympathy of somebody to something or someone. The criterion of displacement means that not only objects or relations at presence can be described but there are also symbols which refer to objects in another time or place. The word \"yesterday\" refers to day before and objects mentioned in a sentence with \"yesterday\" refer to objects from another time than the present one. Displacement is about the communication of events which had happened or will happen and the objects belonging to that event. Having a range of symbols to communicate these symbols can be newly combined. Creativity is the probable most important feature. Our communication is not restricted to a fixed set of topics or predetermined messages. The combination of a finite set of symbols to an infinite number of sentences and meaning. With the infinite number of sentences the creation of novel messages is possible. How creative the human language is can be illustrated by some simple examples like the process that creates verbs from nouns. New words can be created, which do not exist so far, but we are able to understand them. Examples: leave the boat on the beach -\> beach the boat keep the aeroplane on the ground -\> ground the aeroplane write somebody an e-mail -\> e-mail somebody Creative systems are also found in other aspects of language, like the way sounds are combined to form new words. i.e. prab, orgu, zabi could be imagined as names for new products. To avoid an arbitrary combination of symbols without any regular arrangement \"true\" languages need structure dependency. Combining symbols the syntax is relevant. A change in the symbol order might have an impact on the meaning of the sentence. For example "The dog bites the cat" has obviously a different meaning than "The cat bites the dog" based on the different word arrangement of the two sentences. \[edit\] Non-Human Language - Animal Communication \[edit\] Forms of Communication As mentioned before human language is just one of quite a number of communication forms. Different forms of communication can be found in the world of animals. From a little moth to a giant whale, all animals appear to have the use of communication. Not only humans use facial expression for stressing utterances or feeling, facial expressions can be found among apes. The expression, for example \"smiling\" indicates cooperativeness and friendliness in both the human and the ape world. On the other hand an ape showing teeth indicates the willingness to fight. Posture is a very common communicative tool among animals. Lowering the front part of the body and extending the front legs is a sign of dogs that they are playful whereas lowering the full body is a dog's postural way to show its submissiveness. Postural communication is known in both human and non-human primates. Besides facial expression, gesture and posture that are found in human communication, there are other communicative devices which are either just noticeable by the sub-consciousness of humans like scent or cannot be found amongst humans like light, colour and electricity. The chemicals which are used for a communicative function are called pheremones. Those pheremones are used to mark territorial or to signal its reproductive readiness. For animals scent is a very important tool which predominates their mating behaviour. Humans are influenced in their mating behaviour by scent as well but there are more factors to that behaviour so that scent is not predominating. The insects use species-dependent light patterns to signal identity, sex and location. For example the octopus changes colour for signalling territorial defence and mating readiness. In the world of birds colour is wide spread, too. The male peacock has colourful feathering to impress female peahens as a part of mating behaviour. These ways of communication help to live in a community and survive in certain environment. \[edit\] Characteristic Language Features in Animal Communication As mentioned above it is possible to describe the uniqueness of human language by four criteria (semanticity, displacement, creativity and structural dependency) which are important devices in the human language to form a clear communication between humans. To see if these criteria exist in animal communication - i.e. if animals possess a \"true\" language - several experiments with non-human primates were performed. Non-human primates were taught American Sign Language (ASL) and a specially developed token language to detect in how far they are capable of linguistic behaviour. Can semanticity, displacement, creativity and structure dependency be found in non-human language? Experiments 1. In 1931, comparative psychologist Winthrop Niles Kellogg and his wife started an experiment with a chimpanzee, which he raised alongside his own child. The purpose was of course to see how environment influenced development, could chimpanzee be more like human? Eventually the experiment failed, the factors are: the behavior of their son started to become more and more chimpanzee-like and also the tiredness of having to do both experiment and raising two babies at the same time. 2. Human language In 1948, in Orange Park, Florida, Keith and Cathy Hayes tried to teach English words to a chimpanzee named Viki. She was raised as if she were a human child. The chimpanzee was taught to \"speak\" easy English words like \"cup\". The experiment failed since with the supralanyngal anatomy and the vocal fold structure that chimpanzees have it is impossible for them to produce human speech sounds. The failure of the Viki experiment made scientists wonder how far are non-human primates able to communicate linguistically. 3. Sign language From 1965 to 1972 the first important evidence showing rudiments of linguistic behaviour was \"Washoe\", a young female chimpanzee. The experimenters Allen and Beatrice Gardner conducted an experiment where Washoe learned 130 signs of the American Sign Language within three years. Showing pictures of a duck to Washoe and asking WHAT THAT? she combined the symbols of WATER and BIRD to create WATER BIRD as she had not learned the word DUCK (the words in capital letters refer to the signs the apes use to communicate with the experimenter). It was claimed that Washoe was able to arbitrarily combine signs spontaneously and creatively. Some scientists criticised the ASL experiment of Washoe because they claimed that ASL is a loose communicative system and strict syntactic rules are not required. Because of this criticism different experiments were developed and performed which focus on syntactic rules and structure dependency as well as on creative symbol combination. A non-human primate named \"Kanzi\" was trained by Savage-Rumbaugh in 1990. Kanzi was able to deal with 256 geometric symbols and understood complex instructions like GET THE ORANGE THAT IS IN THE COLONY ROOM. The experimenter worked with rewards. A question which arose was whether these non-human primates were able to deal with human-like linguistic capacities or if they were just trained to perform a certain action to get the reward. For more detailed explanations of the experiments see The Mind of an Ape. Can the characteristic language features be found in non-human communication? Creativity seems to be present in animal communication as amongst others Washoe showed with the creation of WATER BIRD for DUCK. Although some critics claimed that creativity is often accidental or like in the case of Washoe's WATER BIRD the creation relays on the fact that water and bird were present. Just because of this presence Washoe invented the word WATER BIRD. In the case of Kanzi a certain form of syntactic rules was observed. In 90% of Kanzi's sentences there was first the invitation to play and then the type of game which Kanzi wanted to play like CHASE HIDE, TICKLE SLAP and GRAB SLAP. The problem which was observed was that it is not always easy to recognise the order of signs. Often facial expression and hand signs are performed at the same time. One ape signed the sentence I LIKE COKE by hugging itself for "like" and forming the sign for "coke" with its hands at the same time. Noticing an order in this sign sentence was not possible. A certain structural dependency could be observed at Kanzi's active and passive sentences. When Matata, a fellow chimpanzee was grabbed Kanzi signed GRAB MATATA and when Matata was performing an action such as biting Kanzi produced MATATA BITE. It has not yet been proved that symbolic behaviour is occurring. Although there are plenty evidences that creativity and displacement occur in animal communication some critics claim that these evidences can be led back to dressage and training. It was claimed that linguistic behaviour cannot be proved as it is more likely to be a training to correctly use linguistic devices. Apes show just to a little degree syntactic behaviour and they are not able to produce sentences containing embedded structures. Some linguists claim that because of such a lack of linguistic features non-human communication cannot be a "true" language. Although we do not know the capacity of an ape\'s mind it does not seem that the range of meanings observed in ape\'s wild life approach the capaciousness of semanticity of human communication. Furthermore apes seem not to care to much about displacement as it appears that they do not communicate about imaginary pasts or futures. All in all non-human primate communication consisting of graded series of communication shows little arbitrariness. The results with non-human primates led to a controversial discussion about linguistic behaviour. Many researchers claimed that the results were influenced by dressage. For humans language is a communication form suited to the patterns of human life. Other communication systems are better suited for fellow creatures and their mode of existence. Now that we know that there is a difference between animal communication and human language we will see detailed features of the human language. \[edit\] Language Comprehension & Production \[edit\] Language features -- Syntax and Semantics In this chapter the main question will be "how do we understand sentences?". To find an answer to that problem it is necessary to have a closer look at the structure of languages. The most important properties every human language provides are rules which determine the permissible sentences and a hierarchical structure (phonemes as basic sounds, which constitute words, which in turn constitute phrases, which constitute sentences, which constitute texts). These feature of a language enable humans to create new unique sentences. The fact that all human languages have a common ground even if they developed completely independent from one another may lead to the conclusion that the ability to process language must be innate. Another evidence of a inborn universal grammar is that there were observations of deaf children who were not taught a language and developed their own form of communication which provided the same basic constituents. Two basic abilities human beings have to communicate is to interpret the syntax of a sentence and the knowledge of the meaning of single words, which in combination enables them to understand the semantic of whole sentences. Many experiments have been done to find out how the syntactical and semantical interpretation is done by human beings and how syntax and semantics works together to construct the right meaning of a sentence. Physiological experiments had been done in which for example the event-related potential (ERP) in the brain was measured as well as behavioristic experiments in which mental chronometry, the measurement of the time-course of cognitive processes, was used. Physiological experiments showed that the syntactical and the semantical interpretation of a sentence takes place separately from each other. These results will be presented below in more detail. ## Physiological Approach Semantical incorrectness in a sentence evokes an N400 in the ERP The exploration of the semantic sentence processing can be done by the measurement of the event-related potential (ERP) when hearing a semantical correct sentence in comparison to a semantical incorrect sentence. For example in one experiment three reactions to sentences were compared: Semantically correct: "The pizza was too hot to eat." Semantically wrong: "The pizza was too hot to drink." Semantically wrong: "The pizza was too hot to cry." In such experiments the ERP evoked by the correct sentence is considered to show the ordinary sentence processing. The variations in the ERP in case of the incorrect sentences in contrast to the ERP of the correct sentence show at what time the mistake is recognized. In case of semantic incorrectness there was observed a strong negative signal about 400ms after perceiving the critical word which did not occure, if the sentence was semantically correct. These effects were observed mainly in the partial and central area. There was also found evidence that the N400 is the stronger the less the word fits semantically. The word "drink" which fits a little bit more in the context caused a weaker N400 than the word "cry". That means the intensity of the N400 correlates with the degree of the semantic mistake. The more difficult it is to search for a semantic interpretation of a sentence the higher is the N400 response. To examine the syntactical aspects of the sentence processing a quite similar experiment as in the case of the semantic processing was done. There were used syntactical correct sentences and incorrect sentences, such as (correct:)"The cats won´t eat..." and (incorrect:)"The cats won´t eating...". When hearing or reading a syntactical incorrect sentence in contrast to a syntactical correct sentence the ERP changes significantly on two different points of time. First of all there a very early increased response to syntactical incorrectness after 120ms. This signal is called the 'early left anterior negativity' because it occurs mainly in the left frontal lobe. This advises that the syntactical processing is located amongst others in Broca\'s area which is located in the left frontal lobe. The early response to syntactical mistakes also indicates that the syntactical mistakes are detected earlier than semantic mistakes. The other change in the ERP when perceiving a syntactical wrong sentence occurs after 600ms in the partial lobe. The signal is increasing positively and is therefore called P600. Possibly the late positive signal is reflecting the attempt to reconstruct the grammatical problematic sentence to find a possible interpretation. <File:Cpnp3001.jpg> Syntactical incorrectness in a sentence evokes after 600ms a P600 in the electrodes above the partial lobe. To summarize the three important ERP-components: First of all there occurs the ELAN at the left frontal lobe which shows a violation of syntactical rules. After it follows the N400 in central and partial areas as a reaction to a semantical incorrectness and finally there occurs a P600 in the partial area which probably means a reanalysis of the wrong sentence. ## Behavioristic Approach -- Parsing a Sentence Behavioristic experiments about how human beings parse a sentence often use syntactically ambiguous sentences. Because it is easier to realize that sentence-analysing mechanisms called parsing take place when using sentences in which we cannot automatically constitute the meaning of the sentence. There are two different theories about how humans parse sentences. The syntax-first approach claims that syntax plays the main part whereas semantics has only a supporting role, whereas the interactionist approach states that both syntax and semantics work together to determine the meaning of a sentence. Both theories will be explained below in more detail. The Syntax-First Approach of Parsing The syntax-first approach concentrates on the role of syntax when parsing a sentence. That humans infer the meaning of a sentence with help of its syntactical structure (Kako and Wagner 2001) can easily be seen when considering Lewis Carroll´s poem 'Jabberwocky': \"Twas brillig, and the slithy toves Did gyre and gimble in the wabe: All mimsy were the borogoves, And the mome raths outgrabe.\" Although most of the words in the poems have no meaning one may ascribe at least some sense to the poem because of its syntactical structure. There are many different syntactic rules that are used when parsing a sentence. One important rule is the principle of late closure which means that a person assumes that a new word he perceives is part of the current phrase. That this principle is used for parsing sentences can be seen very good with help of a so called garden-path sentence. Experiments with garden-path sentences have been done by Frazier and Fayner 1982. One example of a garden-path sentence is: "Because he always jogs a mile seems a short distance to him." When reading this sentence one first wants to continue the phrase "Because he always jogs" by adding "a mile" to the phrase, but when reading further one realizes that the words "a mile" are the beginning of a new phrase. This shows that we parse a sentence by trying to add new words to a phrase as long as possible. Garden-path sentences show that we use the principle of late closure as long it makes syntactically sense to add a word to the current phrase but when the sentence starts to get incorrect semantics are often used to rearrange the sentence. The syntax-first approach does not disregard semantics. According to this approach we use syntax first to parse a sentence and semantics is later on used to make sense of the sentence. Apart from experiments which show how syntax is used for parsing sentences there were also experimens on how semantics can influence the sentence processing. One important experiment about that issue has been done by Daniel Slobin in 1966. He showed that passive sentences are understood faster if the semantics of the words allow only one subject to be the actor. Sentences like "The horse was kicked by the cow." and "The fence was kicked by the cow." are grammatically equal and in both cases only one syntactical parsing is possible. Nevertheless the first sentence semantically provides two subjects as possible actors and therefore it needs longer to parse this sentence. By measuring this significant difference Daniel Slobin showed that semantics play an important role in parsing a sentence, too. ## The Interactionist Approach of Parsing The interactionist approach ascribes a more central role to semantics in parsing a sentence. In contrast to the syntax-first approach, the interactionist theory claims that syntax is not used first but that semantics and syntax are used simultaneously to parse the sentence and that they work together in clarifying the meaning. There have been several experiments which provide evidence that semantics are taken into account from the very beginning reading a sentence. Most of these experiments are working with the eye-tracking techniques and compare the time needed to read syntactical equal sentences in which critical words cause or prohibit ambiguity by semantics. One of these experiments was done by John Trueswell and coworkers in 1994. He measured the eye movement of persons when reading the following two sentences: The defendant examined by the lawyer turned out to be unreliable. The evidence examined by the lawyer turned out to be unreliable. He observed that the time needed to read the words "by the lawyer" took longer in case of the first sentence because in the first sentence the semantics first allow an interpretation in which the defendant is the one who examines, while the evidence only can be examined. This experiment shows that the semantics also play a role while reading the sentence which supports the interactionist approach and argues against the theory that semantics are only used after a sentence has been parsed syntactically. \[edit\] Inferences Creates Coherence Coherence is the semantic relation of information in different parts of a text to each other. In most cases coherence is achieved by inference; that means that a reader draws information out of a text that is not explicitly stated in this text. For further information the chapter \[Neuroscience of Text Comprehension\] should be considered. ## Situation Model A situation model is a mental representation of what a text is about. This approach proposes that the mental representation people form as they read a story does not indicate information about phrases, sentences, paragraphs, but a representation in terms of the people, objects, locations, events described in the story (Goldstein 2005, p. 374) For a more detailed description of situation models, see Situation Models ## Using Language Conversations are dynamic interactions between two or more people (Garrod &Pickering, 2004 as cited in Goldstein 2005). The important thing to mention is that conversation is more than the act of speaking. Each person brings in his or her knowledge and conversations are much easier to process if participants bring in shared knowledge. In this way, participants are responsible of how they bring in new knowledge. H.P. Grice proposed in 1975 a basic principle of conversation and four "conversational maxims." His cooperative principle states that "the speaker and listener agree that the person speaking should strive to make statements that further the agreed goals of conversation." The four maxims state the way of how to achieve this principle. 1\. Quantity: The speaker should try to be informative, no over-/underinformation. 2\. Quality: Do not say things which you believe to be false or lack evidence of. 3\. Manner: Avoiding being obscure or ambiguous. 4\. Relevance: Stay on topic of the exchange. An example of a rule of conversation incorporating three of those maxims is the given-new-contract. It states that the speaker should construct sentences so that they include given and new information. (Haviland & Clark, 1974 as cited in Goldstein, 2005). Consequences of not following this rule were demonstrated by Susan Haviland and Herbert Clark by presenting pairs of sentences (either following or ignoring the given-new-contract) and measuring the time participants needed until they fully understood the sentence. They found that participants needed longer in pairs of the type: ` We checked the picnic supplies. `\ ` The beer was warm.`\ \ ` Rather than:`\ ` We got some beer out of the trunk. `\ ` The beer was warm.` The reason that it took longer to comprehend the second sentence of the first pair is that inferencing has to be done (beer has not been mentioned as being part of the picnic supplies). (Goldstein, 2005, p. 377-378) ## Language, Culture and Cognition In the parts above we saw that there has been a lot of research of language, from letters through words and sentences to whole conversations. Most of the research described in the parts above was processed by English speaking researchers and the participants were English speaking as well. Can those results be generalised for all languages and cultures or might there be a difference between English speaking cultures and for example cultures with Asian or African origin? Imagine our young man from the beginning again: Knut! Now he has to prepare a presentation with his friend Chang for the next psychology seminar. Knut arrives at his friend's flat and enters his living-room, glad that he made it there just in time. They have been working a few minutes when Chang says: "It has become cold in here!" Knut remembers that he did not close the door, stands up and\..."stop! What is happening here?!" This part is concerned with culture and its connection to language. Culture, not necessarily in the sense of \"high culture\" like music, literature and arts but culture is the \"know-how\" a person must have to tackle his or her daily life. This know-how might include high culture but it is not necessary. ## Culture and Language Scientists wondered in how far culture affects the way people use language. In 1991 Yum studied the indirectness of statements in Asian and American conversations. The statement \"Please shut the door\" was formulated by Americans in an indirect way. They might say something like \"The door is open\" to signal that they want to door to be shut. Even more indirect are Asian people. They often do not even mention the door but they might say something like \"It is somewhat cold today\". Another cultural difference affecting the use of language was observed by Nisbett in 2003 in observation about the way people pose questions. When American speaker ask someone if more tea is wanted they ask something like \"More tea?\". Different to this Asian people would ask if the other one would like more drinking as for Asians it seems obvious that tea is involved and therefore mentioning the tea would be redundant. For Americans it is the other way round. For them it seems obvious that drinking is involved so they just mention the tea. This experiment and similar ones indicate that people belonging to Asian cultures are often relation orientated. Asians focus on relationships in groups. Contrasting, the Americans concentrate on objects. The involved object and its features are more important than the object\'s relation to other objects. These two different ways of focusing shows that language is affected by culture. A experiment which clearly shows these results is the mother-child interaction which was observed by Fernald and Morikawa in 1993. They studied mother-child talk of Asian and American mothers. An American mother trying to show and explain a car to her child often repeated the object \"car\" and wants the child to repeat it as well. The mother focuses on the features of the car and labels the importance of the object itself. The Asian mother shows the toy car to her child, gives the car to the child and wants it to give the car back. The mother shortly mentions that the object is a car but concentrates on the importance of the relation and the politeness of giving back the object. Realising that there are plenty differences in how people of different cultures use language the question arises if languages affects the way people think and perceive the world. ## What is the connection between language and cognition? ### Sapir-Whorf Hypothesis In the 1950s Edward Sapir and Benjamin Whorf proposed the hypothesis that the language of a culture affects the way people think and perceive. The controversial theory was question by Elenor Rosch who studied colour perception of Americans and Danis who are members of an stone-age agricultural culture in the Iran. Americans have several different categories for colour as for example blue, red, yellow and so on. Danis just have two main colour categories. The participants were ask to recall colours which were shown to them before. That experiment did not show significant differences in colour perception and memory as the Sapir-Whorf hypothesis presumes. <File:Color-naming> exp.jpg Color-naming experiment by Roberson et al. (2000) ### Categorical Perception Nevertheless a support for the Sapir-Whorf hypothesis was Debi Roberson\'s demonstration for categorical perception based on the colour perception experiment by Rosch. The participants, a group of English-speaking British and another group of Berinmos from New Guinea were ask to name colours of a board with colour chips. The Berinmos distinguish between five different colour categories and the denotation of the colour names is not equivalent to the British colour denotation. Apart from these differences there are huge differences in the organisation of the colour categories. The colours named green and blue by British participants where categorised as nol which also covers colours like light-green, yellow-green, and dark blue. Other colour categories differ similarly. The result of Roberson\'s experiment was that it is easier for British people to discriminate between green and blue whereas Berinmos have less difficulties distinguishing between Nol and Wap. The reaction to colour is affected by language, by the vocabulary we have for denoting colours. It is difficult for people to distinguish colours from the same colour category but people have less trouble differentiating between colours from different categories. Both groups have categorical colour perception but the results for naming colours depends on how the colour categories were named. All in all it was shown that categorical perception is influenced by the language use of different cultures. These experiments about perception and its relation to cultural language usage leads to the question whether thought is related to language with is cultural differences. ## Is thought dependent on, or even caused by language? ### Historical theories An early approach was proposed by J.B. Watson's in 1913. His peripheralist approach was that thought is a tiny not noticeable speech movement. While thinking a person performs speech movements as he or she would do while talking. A couple year later, in 1921 Wittgenstein poses the theory that the limits of a person\'s language mean the limits of that person\'s world. As soon as a person is not able to express a certain content because of a lack of vocabulary that person is not able to think about those contents as they are outside of his or her world. Wittgenstein\'s theory was doubted by some experiments with babies and deaf people. ### Present research To find some evidence for the theory that language and culture is affecting cognition Lian-hwang Chiu designed an experiment with American and Asian children. The children were asked to group objects in pairs so that these objects fit together. On picture that was shown to the children there was a cow, a chicken and some grass. The children had to decided which of the two objects fitted together. The American children mostly grouped cow and chicken because of group of animals they belong to. Asian children more often combined the cow with the grass as there is the relation of the cow normally eating grass. In 2000 Chui repeated the experiment with words instead of pictures. A similar result was observed. The American children sorted their pairs taxonomically. Given the words \"panda\", \"monkey\" and \"banana\" American children paired \"panda\" and monkey\". Chinese children grouped relationally. They put \"monkey\" with \"banana\". Another variation of this experiment was done with bilingual children. When the task was given in English to the children they grouped the objects taxonomically. A Chinese task caused a relational grouping. The language of the task clearly influenced on how to group the objects. That means language may affects the way people think. The results of plenty experiments regarding the relation between language, culture and cognition let assume that culture affects language and cognition is affected by language.Our way of thinking is influenced by the way we talk and thought can occur without language but the exact relation between language and thought remains to be determined. ## Introduction \"Language is the way we interact and communicate, so, naturally, the means of communication and the conceptual background that's behind it, which is more important, are used to try to shape attitudes and opinions and induce conformity and subordination. Not surprisingly, it was created in the more democratic societies.\" - Chomsky Language is a central part of everyday life and communication a natural human necessity. For those reasons there has been a high interest in their properties. However describing the processes of language turns out to be quite hard. We can define language as a system of communication through which we code and express our feelings, thoughts, ideas and experiences.[^1] Already Plato was concerned with the nature of language in his dialogue "Cratylus", where he discussed first ideas about nowadays important principles of linguistics namely morphology and phonology. Gradually philosophers, natural scientists and psychologists became interested in features of language. Since the emergence of the cognitive science in the 50\'s and Chomsky´s criticism on the behaviourist view, language is seen as a cognitive ability of humans, thus incorporating linguistics in other major fields like computer science and psychology. Today, psycho-linguistics is a discipline on its own and its most important topics are acquisition, production and comprehension of language. Especially in the 20th century many studies concerning communication have been conducted, evoking new views on old facts. New techniques, like CT, MRI and fMRI or EEG, as described in Methods of Behavioural and Neuroscience Methods, made it possible to observe brain during communication processes in detail. Later on an overview of the most popular experiments and observed effects is presented. But in order to understand those one needs to have a basic idea of semantics and syntax as well as of linguistic principles for processing words, sentences and full texts. Finally some questions will arise: How is language affected by culture? Or in philosophical terms, the discussion about the relationship between language and thoughts has to be developed. ## Language as a cognitive ability ### Historical review on Psycholinguistics & Neurolinguistics Starting with philosophical approaches, the nature of the human language had ever been a topic of interest. Galileo in the 16th century saw the human language as the most important invention of humans. Later on in the 18th century the scientific study of language began by psychologists. Wilhelm Wundt (founder of the first laboratory of psychology) saw language as the mechanism by which thoughts are transformed into sentences. The observations of Wernike and Broca (see chapter 9) were milestones in the studies of language as a cognitive ability. In the early 1900s the behaviouristic view influenced the study of language very much. In 1957 B.F.Skiner published his book \"Verbal Behaviour\", in which he proposed that learning of language can be seen as a mechanism of reinforcement. Noam Chomsky (quoted at the beginning of this chapter) published in the same year \"Syntactic Structures\". He proposed that the ability to invent language is somehow coded in the genes. That led him to the idea that the underlying basis of language is similar across cultures. There might be some kind of universal grammar as a base, independent of what kind of language (including sign language) might be used by humans. Further on Chomsky published a review of Skinner´s \"Verbal Behaviour\" in which he presented arguments against the behaviouristic view. There are still some scientists who are convinced that it does not need a mentalist approach like Chomsky proposed, but in the meantime most agree that human language has to be seen as a cognitive ability. ### Current goals of Psycholinguistics A natural language can be analysed at a number of different levels. In linguistics we differ between phonology (sounds), morphology (words), syntax (sentence structure), semantics (meaning), and pragmatics (use). Linguists try to find systematic descriptions capturing the regularities inherent in the language itself. But a description of natural language just as a abstract structured system, can not be enough. Psycholinguists rather ask, how the knowledge of language is represented in the brain, and how it is used. Today\'s most important research topics are: 1\) comprehension: How humans understand spoken as well as written language, how language is processed and what interactions with memory are involved. 2\) speech production: Both the physical aspect of speech production, and the mental process that stands behind the uttering of a sentence. 3\) acquisition: How people learn to speak and understand a language. ### Characteristic features What is a language? What kinds of languages do exist? Are there characteristic features that are unique in human language? There are plenty of approaches how to describe languages. Especially in computational linguistics researchers try to find formal definitions for different kinds of languages. But for psychology other aspects of language than its function as pure system of communication are of central interest. Language is also a tool we use for social interactions starting with the exchange of news up to the identification of social groups by their dialect. We use it for expressing our feelings, thoughts, ideas etc. Although there are plenty ways to communicate (consider Non-Human-Language) humans expect their system of communication - the human language to be unique. But what is it that makes the human language so special and unique? Four major criteria have been proposed by Professor Franz Schmalhofer from the University of Osnabrück as explained below: -semanticity -displacement -creativity -structure dependency Semanticity means the usage of symbols. Symbols can either refer to objects or to relations between objects. In the human language words are the basic form of symbols. For example the word \"book\" refers to an object made of paper on which something might be written. A relation symbol is the verb \"to like\" which refers to the sympathy of somebody to something or someone. The criterion of displacement means that not only objects or relations at presence can be described but there are also symbols which refer to objects in another time or place. The word \"yesterday\" refers to day before and objects mentioned in a sentence with \"yesterday\" refer to objects from another time than the present one. Displacement is about the communication of events which had happened or will happen and the objects belonging to that event. Having a range of symbols to communicate these symbols can be newly combined. Creativity is the probable most important feature. Our communication is not restricted to a fixed set of topics or predetermined messages. The combination of a finite set of symbols to an infinite number of sentences and meaning. With the infinite number of sentences the creation of novel messages is possible. How creative the human language is can be illustrated by some simple examples like the process that creates verbs from nouns. New words can be created, which do not exist so far, but we are able to understand them. Examples: leave the boat on the beach -\> beach the boat keep the aeroplane on the ground -\> ground the aeroplane write somebody an e-mail -\> e-mail somebody Creative systems are also found in other aspects of language, like the way sounds are combined to form new words. i.e. prab, orgu, zabi could be imagined as names for new products. To avoid an arbitrary combination of symbols without any regular arrangement \"true\" languages need structure dependency. Combining symbols the syntax is relevant. A change in the symbol order might have an impact on the meaning of the sentence. For example "The dog bites the cat" has obviously a different meaning than "The cat bites the dog" based on the different word arrangement of the two sentences. ## Non-Human Language - Animal Communication ### Forms of Communication As mentioned before human language is just one of quite a number of communication forms. Different forms of communication can be found in the world of animals. From a little moth to a giant whale, all animals appear to have the use of communication. Not only humans use facial expression for stressing utterances or feeling, facial expressions can be found among apes. The expression, for example \"smiling\" indicates cooperativeness and friendliness in both the human and the ape world. On the other hand an ape showing teeth indicates the willingness to fight. Posture is a very common communicative tool among animals. Lowering the front part of the body and extending the front legs is a sign of dogs that they are playful whereas lowering the full body is a dog's postural way to show its submissiveness. Postural communication is known in both human and non-human primates. Besides facial expression, gesture and posture that are found in human communication, there are other communicative devices which are either just noticeable by the sub-consciousness of humans like scent or cannot be found amongst humans like light, colour and electricity. The chemicals which are used for a communicative function are called pheremones. Those pheremones are used to mark territorial or to signal its reproductive readiness. For animals scent is a very important tool which predominates their mating behaviour. Humans are influenced in their mating behaviour by scent as well but there are more factors to that behaviour so that scent is not predominating. The insects use species-dependent light patterns to signal identity, sex and location. For example the octopus changes colour for signalling territorial defence and mating readiness. In the world of birds colour is wide spread, too. The male peacock has colourful feathering to impress female peahens as a part of mating behaviour. These ways of communication help to live in a community and survive in certain environment. ### Characteristic Language Features in Animal Communication As mentioned above it is possible to describe the uniqueness of human language by four criteria (semanticity, displacement, creativity and structural dependency) which are important devices in the human language to form a clear communication between humans. To see if these criteria exist in animal communication - i.e. if animals possess a \"true\" language - several experiments with non-human primates were performed. Non-human primates were taught American Sign Language (ASL) and a specially developed token language to detect in how far they are capable of linguistic behaviour. Can semanticity, displacement, creativity and structure dependency be found in non-human language? Experiments 1. Human language In 1948, in Orange Park, Florida, Keith and Cathy Hayes tried to teach English words to a chimpanzee named Viki. She was raised as if she were a human child. The chimpanzee was taught to \"speak\" easy English words like \"cup\". The experiment failed since with the supralanyngal anatomy and the vocal fold structure that chimpanzees have it is impossible for them to produce human speech sounds. The failure of the Viki experiment made scientists wonder how far are non-human primates able to communicate linguistically. 2. Sign language From 1965 to 1972 the first important evidence showing rudiments of linguistic behaviour was \"Washoe\", a young female chimpanzee. The experimenters Allen and Beatrice Gardner conducted an experiment where Washoe learned 130 signs of the American Sign Language within three years. Showing pictures of a duck to Washoe and asking WHAT THAT? she combined the symbols of WATER and BIRD to create WATER BIRD as she had not learned the word DUCK (the words in capital letters refer to the signs the apes use to communicate with the experimenter). It was claimed that Washoe was able to arbitrarily combine signs spontaneously and creatively. Some scientists criticised the ASL experiment of Washoe because they claimed that ASL is a loose communicative system and strict syntactic rules are not required. Because of this criticism different experiments were developed and performed which focus on syntactic rules and structure dependency as well as on creative symbol combination. A non-human primate named \"Kanzi\" was trained by Savage-Rumbaugh in 1990. Kanzi was able to deal with 256 geometric symbols and understood complex instructions like GET THE ORANGE THAT IS IN THE COLONY ROOM. The experimenter worked with rewards. A question which arose was whether these non-human primates were able to deal with human-like linguistic capacities or if they were just trained to perform a certain action to get the reward. For more detailed explanations of the experiments see The Mind of an Ape. Can the characteristic language features be found in non-human communication? Creativity seems to be present in animal communication as amongst others Washoe showed with the creation of WATER BIRD for DUCK. Although some critics claimed that creativity is often accidental or like in the case of Washoe's WATER BIRD the creation relays on the fact that water and bird were present. Just because of this presence Washoe invented the word WATER BIRD. In the case of Kanzi a certain form of syntactic rules was observed. In 90% of Kanzi's sentences there was first the invitation to play and then the type of game which Kanzi wanted to play like CHASE HIDE, TICKLE SLAP and GRAB SLAP. The problem which was observed was that it is not always easy to recognise the order of signs. Often facial expression and hand signs are performed at the same time. One ape signed the sentence I LIKE COKE by hugging itself for "like" and forming the sign for "coke" with its hands at the same time. Noticing an order in this sign sentence was not possible. A certain structural dependency could be observed at Kanzi's active and passive sentences. When Matata, a fellow chimpanzee was grabbed Kanzi signed GRAB MATATA and when Matata was performing an action such as biting Kanzi produced MATATA BITE. It has not yet been proved that symbolic behaviour is occurring. Although there are plenty evidences that creativity and displacement occur in animal communication some critics claim that these evidences can be led back to dressage and training. It was claimed that linguistic behaviour cannot be proved as it is more likely to be a training to correctly use linguistic devices. Apes show just to a little degree syntactic behaviour and they are not able to produce sentences containing embedded structures. Some linguists claim that because of such a lack of linguistic features non-human communication cannot be a "true" language. Although we do not know the capacity of an ape\'s mind it does not seem that the range of meanings observed in ape\'s wild life approach the capaciousness of semanticity of human communication. Furthermore apes seem not to care to much about displacement as it appears that they do not communicate about imaginary pasts or futures. All in all non-human primate communication consisting of graded series of communication shows little arbitrariness. The results with non-human primates led to a controversial discussion about linguistic behaviour. Many researchers claimed that the results were influenced by dressage. For humans language is a communication form suited to the patterns of human life. Other communication systems are better suited for fellow creatures and their mode of existence. Now that we know that there is a difference between animal communication and human language we will see detailed features of the human language. ## Language Comprehension & Production ### Language features -- Syntax and Semantics In this chapter the main question will be "how do we understand sentences?". To find an answer to that problem it is necessary to have a closer look at the structure of languages. The most important properties every human language provides are rules which determine the permissible sentences and a hierarchical structure (phonemes as basic sounds, which constitute words, which in turn constitute phrases, which constitute sentences, which constitute texts). These feature of a language enable humans to create new unique sentences. The fact that all human languages have a common ground even if they developed completely independent from one another may lead to the conclusion that the ability to process language must be innate. Another evidence of a inborn universal grammar is that there were observations of deaf children who were not taught a language and developed their own form of communication which provided the same basic constituents. Two basic abilities human beings have to communicate is to interpret the syntax of a sentence and the knowledge of the meaning of single words, which in combination enables them to understand the semantic of whole sentences. Many experiments have been done to find out how the syntactical and semantical interpretation is done by human beings and how syntax and semantics works together to construct the right meaning of a sentence. Physiological experiments had been done in which for example the event-related potential (ERP) in the brain was measured as well as behavioristic experiments in which mental chronometry, the measurement of the time-course of cognitive processes, was used. Physiological experiments showed that the syntactical and the semantical interpretation of a sentence takes place separately from each other. These results will be presented below in more detail. Physiological Approach Semantics !Semantical incorrectness in a sentence evokes a N400 in the ERP Semantical incorrectness in a sentence evokes an N400 in the ERP The exploration of the semantic sentence processing can be done by the measurement of the event-related potential (ERP) when hearing a semantical correct sentence in comparison to a semantical incorrect sentence. For example in one experiment three reactions to sentences were compared: Semantically correct: "The pizza was too hot to eat." Semantically wrong: "The pizza was too hot to drink." Semantically wrong: "The pizza was too hot to cry." In such experiments the ERP evoked by the correct sentence is considered to show the ordinary sentence processing. The variations in the ERP in case of the incorrect sentences in contrast to the ERP of the correct sentence show at what time the mistake is recognized. In case of semantic incorrectness there was observed a strong negative signal about 400ms after perceiving the critical word which did not occure, if the sentence was semantically correct. These effects were observed mainly in the partial and central area. There was also found evidence that the N400 is the stronger the less the word fits semantically. The word "drink" which fits a little bit more in the context caused a weaker N400 than the word "cry". That means the intensity of the N400 correlates with the degree of the semantic mistake. The more difficult it is to search for a semantic interpretation of a sentence the higher is the N400 response. Syntax ! Syntactical incorrectness in a sentence can evoke an ELAN (early left anterior negativity) in the electrodes above the left frontal lobe after 120ms. in the electrodes above the left frontal lobe after 120ms.") To examine the syntactical aspects of the sentence processing a quite similar experiment as in the case of the semantic processing was done. There were used syntactical correct sentences and incorrect sentences, such as (correct:)"The cats won´t eat..." and (incorrect:)"The cats won´t eating...". When hearing or reading a syntactical incorrect sentence in contrast to a syntactical correct sentence the ERP changes significantly on two different points of time. First of all there a very early increased response to syntactical incorrectness after 120ms. This signal is called the 'early left anterior negativity' because it occurs mainly in the left frontal lobe. This advises that the syntactical processing is located amongst others in Broca\'s area which is located in the left frontal lobe. The early response to syntactical mistakes also indicates that the syntactical mistakes are detected earlier than semantic mistakes. The other change in the ERP when perceiving a syntactical wrong sentence occurs after 600ms in the partial lobe. The signal is increasing positively and is therefore called P600. Possibly the late positive signal is reflecting the attempt to reconstruct the grammatical problematic sentence to find a possible interpretation. ! Syntactical incorrectness in a sentence evokes after 600ms a P600 in the electrodes above the partial lobe. To summarize the three important ERP-components: First of all there occurs the ELAN at the left frontal lobe which shows a violation of syntactical rules. After it follows the N400 in central and partial areas as a reaction to a semantical incorrectness and finally there occurs a P600 in the partial area which probably means a reanalysis of the wrong sentence. Behavioristic Approach -- Parsing a Sentence Behavioristic experiments about how human beings parse a sentence often use syntactically ambiguous sentences. Because it is easier to realize that sentence-analysing mechanisms called parsing take place when using sentences in which we cannot automatically constitute the meaning of the sentence. There are two different theories about how humans parse sentences. The syntax-first approach claims that syntax plays the main part whereas semantics has only a supporting role, whereas the interactionist approach states that both syntax and semantics work together to determine the meaning of a sentence. Both theories will be explained below in more detail. The Syntax-First Approach of Parsing The syntax-first approach concentrates on the role of syntax when parsing a sentence. That humans infer the meaning of a sentence with help of its syntactical structure (Kako and Wagner 2001) can easily be seen when considering Lewis Carroll´s poem 'Jabberwocky': \"Twas brillig, and the slithy toves Did gyre and gimble in the wabe: All mimsy were the borogoves, And the mome raths outgrabe.\" Although most of the words in the poems have no meaning one may ascribe at least some sense to the poem because of its syntactical structure. There are many different syntactic rules that are used when parsing a sentence. One important rule is the principle of late closure which means that a person assumes that a new word he perceives is part of the current phrase. That this principle is used for parsing sentences can be seen very good with help of a so called garden-path sentence. Experiments with garden-path sentences have been done by Frazier and Fayner 1982. One example of a garden-path sentence is: "Because he always jogs a mile seems a short distance to him." When reading this sentence one first wants to continue the phrase "Because he always jogs" by adding "a mile" to the phrase, but when reading further one realizes that the words "a mile" are the beginning of a new phrase. This shows that we parse a sentence by trying to add new words to a phrase as long as possible. Garden-path sentences show that we use the principle of late closure as long it makes syntactically sense to add a word to the current phrase but when the sentence starts to get incorrect semantics are often used to rearrange the sentence. The syntax-first approach does not disregard semantics. According to this approach we use syntax first to parse a sentence and semantics is later on used to make sense of the sentence. Apart from experiments which show how syntax is used for parsing sentences there were also experimens on how semantics can influence the sentence processing. One important experiment about that issue has been done by Daniel Slobin in 1966. He showed that passive sentences are understood faster if the semantics of the words allow only one subject to be the actor. Sentences like "The horse was kicked by the cow." and "The fence was kicked by the cow." are grammatically equal and in both cases only one syntactical parsing is possible. Nevertheless the first sentence semantically provides two subjects as possible actors and therefore it needs longer to parse this sentence. By measuring this significant difference Daniel Slobin showed that semantics play an important role in parsing a sentence, too. The Interactionist Approach of Parsing The interactionist approach ascribes a more central role to semantics in parsing a sentence. In contrast to the syntax-first approach, the interactionist theory claims that syntax is not used first but that semantics and syntax are used simultanuasly to parse the sentence and that they work together in clearifying the meaning. There have been made several experiments which provide evidence that semantics are taking into account from the very beginning reading a sentence. Most of these experiments are working with the eye-tracking techniques and compare the time needed to read syntactical equal senences in which critical words cause or prohibit ambiguitiy by semantics. One of these experiments has been done by John Trueswell and coworkers in 1994. He measured the eye movement of persons when reading the following two sentences: The defendant examined by the lawyer turned out to be unreliable. The evidence examined by the lawyer turned out to be unreliable. He observed that the time needed to read the words "by the lawyer" took longer in case of the first sentence because in the first sentence the semanics first allow an interpretation in which the defendant is the one who examines, while the evidence only can be examined. This experiment shows that the semantics also play a role while reading the sentence which supports the interactionist approach and argues against the theory that semantics are only used after a sentence has been parsed syntactically. ### Inferences Creates Coherence Coherence is the semantic relation of information in different parts of a text to each other. In most cases coherence is achieved by inference; that means that a reader draws information out of a text that is not explicitly stated in this text. For further information the chapter Psychology and Cognitive Neuroscience/Situation Models and Inferencing#Neuropsychology of Inferencing Neuroscience of Text Comprehension should be considered. ### Situation Model A situation model is a mental representation of what a text is about. This approach proposes that the mental representation people form as they read a story does not indicate information about phrases, sentences, paragraphs, but a representation in terms of the people, objects, locations, events described in the story (Goldstein 2005, p. 374) For a more detailed description of situation models, see Psychology and Cognitive Neuroscience/Situation Models and Inferencing Situation Models ## Using Language Conversations are dynamic interactions between two or more people (Garrod &Pickering, 2004 as cited in Goldstein 2005). The important thing to mention is that conversation is more than the act of speaking. Each person brings in his or her knowledge and conversations are much easier to process if participants bring in shared knowledge. In this way, participants are responsible of how they bring in new knowledge. H.P. Grice proposed in 1975 a basic principle of conversation and four "conversational maxims." His cooperative principle states that "the speaker and listener agree that the person speaking should strive to make statements that further the agreed goals of conversation." The four maxims state the way of how to achieve this principle. 1\. Quantity: The speaker should try to be informative, no over-/underinformation. 2\. Quality: Do not say things which you believe to be false or lack evidence of. 3\. Manner: Avoiding being obscure or ambiguous. 4\. Relevance: Stay on topic of the exchange. An example of a rule of conversation incorporating three of those maxims is the given-new-contract. It states that the speaker should construct sentences so that they include given and new information. (Haviland & Clark, 1974 as cited in Goldstein, 2005). Consequences of not following this rule were demonstrated by Susan Haviland and Herbert Clark by presenting pairs of sentences (either following or ignoring the given-new-contract) and measuring the time participants needed until they fully understood the sentence. They found that participants needed longer in pairs of the type: ` We checked the picnic supplies. `\ ` The beer was warm.` ` Rather than:`\ ` We got some beer out of the trunk. `\ ` The beer was warm.` The reason that it took longer to comprehend the second sentence of the first pair is that inferencing has to be done (beer has not been mentioned as being part of the picnic supplies). (Goldstein, 2005, p. 377-378) ## Language, Culture and Cognition In the parts above we saw that there has been a lot of research of language, from letters through words and sentences to whole conversations. Most of the research described in the parts above was processed by English speaking researchers and the participants were English speaking as well. Can those results be generalised for all languages and cultures or might there be a difference between English speaking cultures and for example cultures with Asian or African origin? Imagine our young man from the beginning again: Knut! Now he has to prepare a presentation with his friend Chang for the next psychology seminar. Knut arrives at his friend's flat and enters his living-room, glad that he made it there just in time. They have been working a few minutes when Chang says: "It has become cold in here!" Knut remembers that he did not close the door, stands up and\..."stop! What is happening here?!" This part is concerned with culture and its connection to language. Culture, not necessarily in the sense of \"high culture\" like music, literature and arts but culture is the \"know-how\" a person must have to tackle his or her daily life. This know-how might include high culture but it is not necessary. Culture and Language Scientists wondered in how far culture affects the way people use language. In 1991 Yum studied the indirectness of statements in Asian and American conversations. The statement \"Please shut the door\" was formulated by Americans in an indirect way. They might say something like \"The door is open\" to signal that they want to door to be shut. Even more indirect are Asian people. They often do not even mention the door but they might say something like \"It is somewhat cold today\". Another cultural difference affecting the use of language was observed by Nisbett in 2003 in observation about the way people pose questions. When American speaker ask someone if more tea is wanted they ask something like \"More tea?\". Different to this Asian people would ask if the other one would like more drinking as for Asians it seems obvious that tea is involved and therefore mentioning the tea would be redundant. For Americans it is the other way round. For them it seems obvious that drinking is involved so they just mention the tea. This experiment and similar ones indicate that people belonging to Asian cultures are often relation orientated. Asians focus on relationships in groups. Contrasting, the Americans concentrate on objects. The involved object and its features are more important than the object\'s relation to other objects. These two different ways of focusing shows that language is affected by culture. A experiment which clearly shows these results is the mother-child interaction which was observed by Fernald and Morikawa in 1993. They studied mother-child talk of Asian and American mothers. An American mother trying to show and explain a car to her child often repeated the object \"car\" and wants the child to repeat it as well. The mother focuses on the features of the car and labels the importance of the object itself. The Asian mother shows the toy car to her child, gives the car to the child and wants it to give the car back. The mother shortly mentions that the object is a car but concentrates on the importance of the relation and the politeness of giving back the object. Realising that there are plenty differences in how people of different cultures use language the question arises if languages affects the way people think and perceive the world. ### What is the connection between language and cognition? Sapir-Whorf Hypothesis In the 1950s Edward Sapir and Benjamin Whorf proposed the hypothesis that the language of a culture affects the way people think and perceive. The controversial theory was question by Elenor Rosch who studied colour perception of Americans and Danis who are members of an stone-age agricultural culture in the Iran. Americans have several different categories for colour as for example blue, red, yellow and so on. Danis just have two main colour categories. The participants were ask to recall colours which were shown to them before. That experiment did not show significant differences in colour perception and memory as the Sapir-Whorf hypothesis presumes. !Color-naming experiment by Roberson et al. (2000)") Categorical Perception Nevertheless a support for the Sapir-Whorf hypothesis was Debi Roberson\'s demonstration for categorical perception based on the colour perception experiment by Rosch. The participants, a group of English-speaking British and another group of Berinmos from New Guinea were ask to name colours of a board with colour chips. The Berinmos distinguish between five different colour categories and the denotation of the colour names is not equivalent to the British colour denotation. Apart from these differences there are huge differences in the organisation of the colour categories. The colours named green and blue by British participants where categorised as nol which also covers colours like light-green, yellow-green, and dark blue. Other colour categories differ similarly. The result of Roberson\'s experiment was that it is easier for British people to discriminate between green and blue whereas Berinmos have less difficulties distinguishing between Nol and Wap. The reaction to colour is affected by language, by the vocabulary we have for denoting colours. It is difficult for people to distinguish colours from the same colour category but people have less trouble differentiating between colours from different categories. Both groups have categorical colour perception but the results for naming colours depends on how the colour categories were named. All in all it was shown that categorical perception is influenced by the language use of different cultures. These experiments about perception and its relation to cultural language usage leads to the question whether thought is related to language with is cultural differences. ### Is thought dependent on, or even caused by language? Historical theories An early approach was proposed by J.B. Watson's in 1913. His peripheralist approach was that thought is a tiny not noticeable speech movement. While thinking a person performs speech movements as he or she would do while talking. A couple year later, in 1921 Wittgenstein poses the theory that the limits of a person\'s language mean the limits of that person\'s world. As soon as a person is not able to express a certain content because of a lack of vocabulary that person is not able to think about those contents as they are outside of his or her world. Wittgenstein\'s theory was doubted by some experiments with babies and deaf people. Present research To find some evidence for the theory that language and culture is affecting cognition Lian-hwang Chiu designed an experiment with American and Asian children. The children were asked to group objects in pairs so that these objects fit together. On picture that was shown to the children there was a cow, a chicken and some grass. The children had to decided which of the two objects fitted together. The American children mostly grouped cow and chicken because of group of animals they belong to. Asian children more often combined the cow with the grass as there is the relation of the cow normally eating grass. In 2000 Chui repeated the experiment with words instead of pictures. A similar result was observed. The American children sorted their pairs taxonomically. Given the words \"panda\", \"monkey\" and \"banana\" American children paired \"panda\" and monkey\". Chinese children grouped relationally. They put \"monkey\" with \"banana\". Another variation of this experiment was done with bilingual children. When the task was given in English to the children they grouped the objects taxonomically. A Chinese task caused a relational grouping. The language of the task clearly influenced on how to group the objects. That means language may affects the way people think. The results of plenty experiments regarding the relation between language, culture and cognition let assume that culture affects language and cognition is affected by language.Our way of thinking is influenced by the way we talk and thought can occur without language but the exact relation between language and thought remains to be determined. ## References ```{=html} <references/> ``` ------------------------------------------------------------------------ Books - O\'Grady, W.; Dobrovolsky, M.; Katamba, F.: Contemporary Linguistics. Copp Clark Pittmann Ltd. (1996) - Banich, Marie T. : Neuropsychology. The neural bases of mental function. (1997) - Goldstein, E.B.: Cognitive Psychology: Connecting Mind, Research and Everyday Experience. (2005) - Akmajian, A.; Demers, R. A.; Farmer, A. K.; Harnish R. M.: Linguistics - An Introductin to Language and Communication, fifth Edition; the MIT Press Cambridge, Massachusetts, London, England; (2001) - Yule, G.: The study of language, second edition, Cambridge University Press; (1996) - Premack, D.; Premack, A.J.: The Mind of an Ape. W W Norton & Co Ltd.(1984) ------------------------------------------------------------------------ Journals - MacCorquodale, K.: On Chomsky´s Review of Skinner´s verbal Behavior. Journal of experimental analysis of behaviour. (1970) Nr.1 Chap. 13, p. 83-99, - Stemmer, N: Skinner\'s verbal behaviour, Chomsky\'s review, and mentalism. Journal of experimental analysis of behaviour. (1990) Nr.3 Chap. 54, p. 307-315 - Chomsky, N.: Collateral Language. TRANS, Internet journal for cultural sciences.(2003) Nr. 15 ## Links & Further reading Cognitive Psychology and Cognitive Neuroscience/Comprehension [^1]: E. B. Goldstein, \"Cognitive Psychology - Connecting Mind, Research, and Everyday Experience\" (2005), page 346
# Cognitive Psychology and Cognitive Neuroscience/Neuroscience of Text Comprehension +:------------------------------+:----:+------------------------------:+ \| Previous \| [O \| [Next \| \| Chapter \| (Cog \| _Neuroscience/Situation_Model \| \| \| niti \| s_and_Inferencing "wikilink") \| \| \| ve_P \| \| \| \| sych \| \| \| \| olog \| \| \| \| y_an \| \| \| \| d_Co \| \| \| \| gnit \| \| \| \| ive_ \| \| \| \| Neur \| \| \| \| osci \| \| \| \| ence \| \| \| \| "wi \| \| \| \| kili \| \| \| \| nk") \| \| +-------------------------------+------+-------------------------------+ ## Introduction What is happening inside my head when I listen to a sentence? How do I process written words? This chapter will take a closer look on brain processes concerned with language comprehension. Dealing with natural language understanding, we distinguish between the neuroscientific and the psycholinguistic approach. As text understanding spreads through the broad field of cognitive psychology, linguistics, and neurosciences, our main focus will lay on the intersection of two latter, which is known as neurolinguistics. Different brain areas need to be examined in order to find out how words and sentences are being processed. For long time scientist were restricted to draw conclusions from certain brain lesions to the functions of corresponding brain areas. During the last 40 years techniques for brain imaging and ERP-measurement have been established which allow for a more accurate identification of brain parts involved in language processing. Scientific studies on these phenomena are generally divided into research on auditory and visual language comprehension; we will discuss both. Not to forget is that it is not enough to examine English: To understand language processing in general, we have to look at non-Indo-European and other language systems like sign language. But first of all we will be concerned with a rough localization of language in the brain. ## Lateralization of language Although functional lateralization studies and analyses find individual differences in personality or cognitive style don\'t favor one hemisphere or the other, some brain functions occur in one or the other side of the brain. Language tends to be on the left and attention on the right (Nielson, Zielinski, Ferguson, Lainhart & Anderson, 2013). There is a lot of evidence that each brain hemisphere has its own distinct functions in language comprehension. Most often, the right hemisphere is referred to as the non-dominant hemisphere and the left is seen as the dominant hemisphere. This distinction is called lateralization (from the Latin word lateral, meaning sidewise) and reason for it first was raised by experiments with split-brain patients. Following a top-down approach we will then discuss the right hemisphere which might have the mayor role in higher level comprehension, but is not quite well understood. Much research has been done on the left hemisphere and we will discuss why it might be dominant before the following sections discuss the fairly well understood fundamental processing of language in this hemisphere of the brain. ### Functional asymmetry Anatomical differences between left and right hemisphere Initially we will consider the most apparent part of a differentiation between left and right hemisphere: Their differences in shape and structure. As visible to the naked eye there exists a clear asymmetry between the two halves of the human brain: The right hemisphere typically has a bigger, wider and farther extended frontal region than the left hemisphere, whereas the left hemisphere is bigger, wider and extends farther in it's occipital region (M. T. Banich,\"Neuropsychology\", ch.3, pg.92). Significantly larger on the left side in most human brains is a certain part of the temporal lobe's surface, which is called the planum temporale. It is localized near Wernicke's area and other auditory association areas, wherefore we can already speculate that the left hemisphere might be stronger involved in processes of language and speech treatment. In fact such a left laterality of language functions is evident in 97% of the population (D. Purves, \"Neuroscience\", ch.26, pg.649). But actually the percentage of human brains, in which a \"left-dominance\" of the planum temporale is traceable, is only 67% (D. Purves, \"Neuroscience\", ch.26, pg.648). Which other factors play aunsolved yet. Evidence for functional asymmetry from \"split brain\" patients In hard cases of epilepsy a rarely performed but popular surgical method to reduce the frequency of epileptic seizures is the so-called corpus callosotomy. Here a radical cut through the connecting \"communication bridge\" between right and left hemisphere, the corpus callosum, is done; the result is a \"split-brain\". For patients whose corpus callosum is cut, the risk of accidental physical injury is mitigated, but the side-effect is striking: Due to this eradicative transection of left and right half of the brain these two are not longer able to communicate adequately. This situation provides the opportunity to study differentiation of functionality between the hemispheres. First experiments with split-brain patients were performed by Roger Sperry and his colleagues at the California Institute of Technology in 1960 and 1970 (D. Purves, \"Neuroscience\", ch.26, pg.646). They lead researchers to sweeping conclusions about laterality of speech and the organization of the human brain in general. ```{=html} <center> ``` ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- A digression on the laterality of the visual system !Visual systemA visual stimulus, located within the left visual field, projects onto the nasal (inner) part of the left eye's retina and onto the temporal (outer) part of the right eye's retina. Images on the temporal retinal region are processed in the visual cortex of the same side of the brain (ipsilateral), whereas nasal retinal information is mapped onto the opposite half of the brain (contralateral). The stimulus within the left visual field will completely arrive in the right visual cortex to be processed and worked up. In \"healthy\" brains this information furthermore attains the left hemisphere via the corpus callosum and can be integrated there. In split-brain patients this current of signals is interrupted; the stimulus remains \"invisible\" for the left hemisphere. ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ```{=html} </center> ``` !Split Brain Experiments{width="300"}The experiment we consider now is based on the laterality of the visual system: What is seen in the left half of the visual field will be processed in the right hemisphere and vice versa. Aware of this principle a test operator presents the picture of an object to one half of the visual field while the participant is instructed to name the seen object, and to blindly pick it out of an amount of concrete objects with the contralateral hand. It can be shown that a picture, for example the drawing of a die, which has only been presented to the left hemisphere, can be named by the participant (\"I saw a die\"), but is not selectable with the right hand (no idea which object to choose from the table). Contrarily the participant is unable to name the die, if it was recognized in the right hemisphere, but easily picks it out of the heap of objects on the table with the help of the left hand. These outcomes are clear evidence of the human brain's functional asymmetry. The left hemisphere seems to dominate functions of speech and language processing, but is unable to handle spatial tasks like vision-independent object recognition. The right hemisphere seems to dominate spatial functions, but is unable to process words and meaning independently. In a second experiment evidence arose that a split-brain patient can only follow a written command (like \"get up now!\"), if it is presented to the left hemisphere. The right hemisphere can only \"understand\" pictorial instructions. The following table (D. Purves, \"Neuroscience\", ch.26, pg.647) gives a rough distinction of functions: ```{=html} <center> ``` +------------------------------------+-----------------------------------+ \| Left Hemisphere \| Right Hemisphere \| +------------------------------------+-----------------------------------+ \| - analysis of right visual field \| - analysis of left visual field \| \| - language processing \| - spatial tasks \| \| - writing \| - visuospatial tasks \| \| - speech \| - object and face recognition \| +------------------------------------+-----------------------------------+ ```{=html} </center> ``` First it is important to keep in mind that these distinctions comprise only functional dominances, no exclusive competences. In cases of unilateral brain damage, often one half of the brain takes over tasks of the other one. Furthermore it should be mentioned that this experiment works only for stimuli presented for less than a second. This is because not only the corpus callosum, but as well some subcortical commissures serve for interhemispheric transfer. In general both can simultaneously contribute to performance, since they use complement roles in processing. ```{=html} <center> ``` +----------------------------------------------------------------------+ \| A digression on handedness \| +----------------------------------------------------------------------+ \| An important issue, when exploring the different brain organization, \| \| is handedness, which is the tendency to use the left or the right \| \| hand to perform activities. Throughout history, left-handers, which \| \| only comprise about 10% of the population, have often been \| \| considered being something abnormal. They were said to be evil, \| \| stubborn, defiant and were, even until the mid 20th century, forced \| \| to write with their right hand. \| \| \| \| One most commonly accepted idea, as to how handedness affects the \| \| hemispheres, is the brain hemisphere division of labour. Since both \| \| speaking and handiwork require fine motor skills, the presumption \| \| here is that it would be more efficient to have one brain hemisphere \| \| do both, rather than having it divided up. Since in most people, the \| \| left side of the brain controls speaking, right-handedness \| \| predominates. The theory also predicts that left-handed people have \| \| a reversed brain division of labour. \| \| \| \| In right handers, verbal processing is mostly done in the left \| \| hemisphere, whereas visuospatial processing is mostly done in the \| \| opposite hemisphere. Therefore, 95% of speech output is controlled \| \| by the left brain hemisphere, whereas only 5% of individuals control \| \| speech output in their right hemisphere. Left-handers, on the other \| \| hand, have a heterogeneous brain organization. Their brain \| \| hemisphere is either organized in the same way as right handers, the \| \| opposite way, or even such that both hemispheres are used for verbal \| \| processing. But usually, in 70% of the cases, speech is controlled \| \| by the left-hemisphere, 15% by the right and 15% by either \| \| hemisphere. When the average is taken across all types of \| \| left-handedness, it appears that left-handers are less lateralized. \| \| \| \| After, for example, damage occurs to the left hemisphere, it follows \| \| that there is a visuospatial deficit, which is usually more severe \| \| in left-handers than in right-handers. Dissimilarities may derive, \| \| in part, from differences in brain morphology, which concludes from \| \| asymmetries in the planum temporale. Still, it can be assumed that \| \| left-handers have less division of labour between their two \| \| hemispheres than right-handers do and are more likely to lack \| \| neuroanatomical asymmetries. \| \| \| \| There have been many theories as to find out why people are \| \| left-handed and what its consequences may be. Some people say that \| \| left-handers have a shorter life span or higher accident rates or \| \| autoimmune disorders. According to the theory of Geschwind and \| \| Galaburda, there is a relation to sex hormones, the immune system, \| \| and profiles of cognitive abilities that determine, whether a person \| \| is left-handed or not. Concludingly, many genetic models have been \| \| proposed, yet the causes and consequences still remain a mystery \| \| (M.T.Banich, \"Neuropsychology\", ch.3, pg. 119). \| +----------------------------------------------------------------------+ ```{=html} </center> ``` ### The right hemisphere The role of the right hemisphere in text comprehension The experiments with \"split-brain\" patients and evidence that will be discussed soon suggest that the right hemisphere is usually not (but in some cases, e.g. 15% of left handed people) dominant in language comprehension. What is most often ascribed to the right hemisphere is cognitive functioning. When damage is done to this part of the brain or when temporal regions of the right hemisphere are removed, this can lead to cognitive-communication problems, such as impaired memory, attention problems, and poor reasoning (L. Cherney, 2001). Investigations lead to the conclusion that the right hemisphere processes information in a gestalt and holistic fashion, with a special emphasis on spatial relationships. Here, an advantage arises for differentiating two distinct faces because it examines things in a global manner and it also reacts to lower spatial, and also auditory, frequency. The former point can be undermined with the fact that the right hemisphere is capable of reading most concrete words and can make simple grammatical comparisons (M. T. Banich,"Neuropsychology", ch.3, pg.97). But in order to function in such a way, there must be some sort of communication between the brain halves. Prosody - the sound envelope around words Consider how different the simple statement \"She did it again\" could be interpreted in the following context taken from Banich: LYNN: Alice is way into this mountain-biking thing. After breaking her arm, you\'d think she\'d be a little more cautious. But then yesterday, she went out and rode Captain Jack\'s. That trail is gnarly - narrow with lots of tree roots and rocks. And last night, I heard that she took a bad tumble on her way down. SARA: She did it again Does Sara say that with rising pitch or emphatically and with falling intonation? In the first case she would ask whether Alice has injured herself again. In the other case she asserts something she knows or imagines: That Alice managed to hurt herself a second time. Obviously the sound envelope around words - prosody - does matter. Reason to belief that recognition of prosodic patterns appears in the right hemisphere arises when you take into account patients that have damage to an anterior region of the right hemisphere. They suffer from aprosodic speech, that is, their utterances are all at the same pitch. They might sound like a robot from the 80ties. There is another phenomena appearing from brain damage: dysprosodic speech. In that case the patient speaks with disordered intonation. This is not due to a right hemisphere lesion, but arises when damage to the left hemisphere is suffered. The explanation is that the left hemisphere gives ill-timed prosodic cues to the right hemisphere, thus proper intonation is affected. Beyond words: Inference from a neurological point of view On the word level, the current studies are mostly consistent with each other and with findings from brain lesion studies. But when it comes to the more complex understanding of whole sentences, texts and storylines, the findings are split. According to E. C. Ferstl's review "The Neuroanatomy of Text Comprehension. What's the story so far?" (2004), there is evidence for and against right hemisphere regions playing the key role in pragmatics and text comprehension. On the current state of knowledge, we cannot exactly say how and where cognitive functions like building situation models and inferencing work together with "pure" language processes. As this chapter is concerned with the neurology of language, it should be remarked that patients with right hemisphere damage have difficulties with inferencing. Take into account the following sentence: With mosquitoes, gnats, and grasshoppers flying all about, she came across a small black bug that was being used to eavesdrop on her conversation. You might have to reinterpret the sentence until you realize that \"small black bug\" does not refer to an animal but rather to a spy device. People with damage in the right hemisphere have problems to do so. They have difficulty to follow the thread of a story and to make inferences about what has been said. Furthermore they have a hard time understanding non-literal aspects of sentences like metaphors, so they might be really horrified when they hear that someone was \"Crying her eyes out\". The reader is referred to the next chapter for a detailed discussion of Situation Models ### The left hemisphere Further evidence for left hemisphere dominance: The Wada technique Before concerning concrete functionality of the left hemisphere, further evidence for the dominance of the left hemisphere is provided. Of relevance is the so-called Wada technique, allowing testing which hemisphere is responsible for speech output and usually being used in epilepsy patients during surgery. It is not a brain imaging technique, but simulates a brain lesion. One of the hemispheres is anesthetized by injecting a barbiturate (sodium amobarbital) in one of the patient's carotid arteries. Then he is asked to name a number of items on cards. When he is not able to do that, despite the fact that he could do it an hour earlier, the concerned hemisphere is said to be the one responsible for speech output. This test must be done twice, for there is a chance that the patient produces speech bilaterally. The probability for that is not very high, in fact, according to Rasmussen & Milner 1997a (as referred to in Banich, p. 293) it occurs only in 15% of the left-handers and none of the right-handers. (It is still unclear where these differences in left-handers' brains come from.) That means that in most people, only one hemisphere "produces" speech output -- and in 96% of right-handers and 70% of left-handers, it is the left one. The findings of the brain lesion studies about asymmetry were confirmed here: Normally (in healthy right-handers), the left hemisphere controls speech output. Explanations of left hemisphere dominance Two theories why the left hemisphere might have special language capacities are still discussed. The first states that dominance of the left hemisphere is due to a specialization for precise temporal control of oral and manual articulators. Here the main argument is that gestures related to a story line are most often made with the right and therefore by the left hemisphere controlled hand whilst other hand movements appear equally often with both hands. The other theory says that the left hemisphere is dominant because it is specialized for linguistic processing and is due to a single patient - a speaker of American Sign Language with a left hemisphere lesion. He could neither produce nor comprehend ASL, but could still communicate by using gestures in non-linguistic domains. How innate is the organisational structure of the brain? Not only cases of left-handers but also brain imaging techniques have shown examples of bilateral language processing: According to ERP studies (by Bellugi et al. 1994 and Neville et al. 1993 as cited in E. Dabrowska, \"Language, Mind an Brain\" 2004, p. 57), people with the Williams' syndrome (WS) also have no dominant hemisphere for language. WS patients have a lot of physical and mental disorders, but show, compared to their other (poor) cognitive abilities, very good linguistic skills. And these skills do not rely on one dominant hemisphere, but both of them contribute equally. So, whilst the majority of the population has a dominant left hemisphere for language processing there are a variety of exceptions to that dominance. That there are different "organisation possibilities" in individual brains Dabrowska (p. 57) suggests that the organisational structure in the brain could be less innate and fixed as it is commonly thought. ## Auditory Language Processing This section will explain where and how language is processed. To avoid intersections with visual processes we will firstly concentrate on spoken language. Scientists have developed three approaches of conceiving information about this issue. The first two approaches are based upon brain lesions, namely aphasia, whereas the recent approach relies on results of on modern brain-image techniques. ### Neurological Perspective The Neurological Perspective describes which pathways language follows in order to be comprehended. Scientists revealed that there are concrete areas inside the brain where concrete tasks of language processing are taking place. The most known areas are the Broca and the Wernicke Area. Broca's aphasia !Broca\'s and Wernicke\'s area One of the most well-known aphasias is Broca's aphasia that causes patients to be unable to speak fluently. Moreover they have a great difficulty producing words. Comprehension, however, is relatively intact in those patients. Because these symptoms do not result from motoric problems of the vocal musculature, a region in the brain that is responsible for linguistic output must be lesioned. Broca discovered that the brain region causing fluent speech is responsible for linguistic output, must be located ventrally in the frontal lobe, anterior to the motor strip. Recent research suggested that Broca\`s aphasia results also from subcortical tissue and white matter and not only cortical tissue. ```{=html} <center> ``` Example of spontaneous Speech - Task: What do you see on this picture? ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- „O, yea. Det's a boy an' girl\... an' \... a \... car \... house\... light po' (pole). Dog an' a \... boat. ‚N det's a \... mm \... a \... coffee, an' reading. Det's a \... mm \... a \... det's a boy \... fishin'." (Adapted from „Principles of Neuroscience" 4th edition, 2000, p 1178) ```{=html} </center> ``` Wernicke's aphasia Another very famous aphasia, known as Wernicke\`s aphasia, causes opposite syndromes. Patients suffering from Wernicke\`s aphasia usually speak very fluently, words are pronounced correctly, but they are combined senselessly -- "word salad" is the way it is most often described. Understanding what patients of Wernicke\`s aphasia say is especially difficult, because they use paraphasias (substitution of a word in verbal paraphasia, of word with similar meaning in semantic paraphasia, and of a phoneme in phonemic paraphasia) and neologisms. With Wernicke\`s aphasia the comprehension of simple sentences is a very difficult task. Moreover their ability to process auditory language input and also written language is impaired. With some knowledge about the brainstructure and their tasks one is able to conclude that the area that causes Wernicke\`s aphasia, is situated at the joint of temporal, parietal and occipital regions, near Heschl\`s gyrus (primary auditory area), because all the areas receiving and interpreting sensory information (posterior cortex), and those connecting the sensory information to meaning (parietal lobe) are likely to be involved. ```{=html} <center> ``` Example of spontaneous Speech - Task: What do you see on this picture? ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- „Ah, yes, it's ah \... several things. It's a girl \... uncurl \... on a boat. A dog \... 'S is another dog \... uh-oh \... long's \... on a boat. The lady, it's a young lady. An' a man a They were eatin'. 'S be place there. This \... a tree! A boat. No, this is a \... It's a house. Over in here \... a cake. An' it's, it's a lot of water. Ah, all right. I think I mentioned about that boat. I noticed a boat being there. I did mention that before \... Several things down, different things down \... a bat \... a cake \... you have a \..." (adapted from „Principles of Neuroscience" 4th edition, 2000, p 1178) ```{=html} </center> ``` Conduction aphasia Wernicke supposed that an aphasia between Broca's area and Wernicke's area, namely conduction aphasia, would lead to severe problems to repeat just heard sentences rather than having problems with the comprehension and production of speech. Indeed patients suffering from this kind of aphasia show an inability to reproduce sentences since they often make phonemic paraphasias, may substitute or leave out words, or might say nothing. Investigations determined that the \"connection cable\", namely the arcuate fasciculus between Wernicke's and Broca's area is almost invariably damaged in case of a conduction aphasia. That is why conduction aphasia is also regarded as a disconnection syndrome (the behavioural dysfunction because of a damage to the connection of two connected brain regions). ```{=html} <center> ``` Example of the repetition of the sentence „The pastry-cook was elated": ------------------------------------------------------------------------------------------------------------------ „The baker-er was /vaskerin/ \... uh \..." (adapted from „Principles of Neuroscience" 4th edition, 2000, p 1178) ```{=html} </center> ``` Transcortical motor aphasia and global aphasia Transcortical motor aphasia, another brain lesion caused by a connection disruption, is very similar to Broca\`s aphasia, with the difference that the ability to repeat is kept. In fact people with a transcortical motor aphasia often suffer from echolalia, the need to repeat what they just heard. Usually patients\` brain is damaged outside Broca\`s area, sometimes more anterior and sometimes more superior. Individuals with transcortical sensory aphasia have similar symptoms as those suffering from Wernicke\`s aphasia, except that they show signs of echolalia. Lesions in great parts of the left hemisphere lead to global aphasia, and thus to an inability of both comprehending and producing language, because not only Broca\`s or Wenicke\`s area is damaged. (Barnich, 1997, pp. 276--282) ```{=html} <center> ``` +----------+----------+----------+----------+----------+----------+ \| Type \| Spo \| *Para \| \| Repe \| \| \| of \| ntaneous \| phasia** \| Compreh \| tition* \| Naming \| \| A \| Speech \| \| ension \| \| \| \| phasia \| \| \| \| \| \| +----------+----------+----------+----------+----------+----------+ \| - \| - N \| - \| - Good \| - Poor \| - Poor \| \| Broca\`s \| onfluent \| Uncommon \| - Poor \| - Poor \| - Poor \| \| - Wer \| - \| - \| - Good \| - Poor \| - Poor \| \| nicke\`s \| Fluent \| Common \| - Good \| - Good \| - Poor \| \| - Co \| - \| \| - Poor \| (ec \| - Poor \| \| nduction \| Fluent \| (verbal) \| - Poor \| holalia) \| - Poor \| \| - \| - N \| - \| \| - Good \| \| \| Trans \| onfluent \| Common \| \| (ec \| \| \| cortical \| - \| ( \| \| holalia) \| \| \| \| Fluent \| literal) \| \| - Poor \| \| \| motor \| - N \| - \| \| \| \| \| - \| onfluent \| Uncommon \| \| \| \| \| Trans \| \| - \| \| \| \| \| cortical \| \| Common \| \| \| \| \| \| \| - \| \| \| \| \| sensory \| \| Variable \| \| \| \| \| - \| \| \| \| \| \| \| Global \| \| \| \| \| \| +----------+----------+----------+----------+----------+----------+ `<small>`{=html}Overview of the effects of aphasia from the neurological perspective`</small>`{=html} ```{=html} </center> ``` (Adapted from Benson, 1985,p. 32 as cited in Barnich, 1997, p. 287) ### Psychological Perspective Since the 1960's psychologists and psycholinguists tried to resolve how language is organised and represented inside the brain. Patients with aphasias gave good evidence for location and discrimination of the three main parts of language comprehension and production, namely phonology, syntax and semantics. Phonology Phonology deals with the processing of meaningful parts of speech resulting from the mere sound. More over there exists a differentiation between a phonemic representation of a speech sound which are the smallest units of sounds that leads to different meanings (e.g. the /b/ and /p/ in bet and pat) and phonetic representation. The latter means that a speech sound may be produced in a different manner at different situations. For instance the /p/ in pill sounds different than the /p/ in spill since the former /p/ is aspirated and the latter is not. Examining which parts are responsible for phonetic representation, patients with Broca\`s or Wernicke\`s aphasia can be compared. As the speech characteristic for patients with Broca\`s aphasia is non-fluent, i.e. they have problems producing the correct phonetic and phonemic representation of a sound, and people with Wernicke\`s aphasia do not show any problems speaking fluently, but also have problems producing the right phoneme. This indicates that Broca\`s area is mainly involved in phonological production and also, that phonemic and phonetic representation do not take place in the same part of the brain. Scientists examined on a more precise level the speech production, on the level of the distinctive features of phonemes, to see in which features patients with aphasia made mistakes. A distinctive feature describes the different manners and places of articulation. /t/ (like in touch) and /s/ (like in such) for example are created at the same place but produced in different manner. /t/ and /d/ are created at the same place and in the same manner but they differ in voicing. Results show that in fluent as well as in non-fluent aphasia patients usually mix up only one distinctive feature, not two. In general it can be said that errors connected to the place of articulation are more common than those linked to voicing. Interestingly some aphasia patients are well aware of the different features of two phonemes, yet they are unable to produce the right sound. This suggests that though patients have great difficulty pronouncing words correctly, their comprehension of words is still quite good. This is characteristic for patients with Broca\`s aphasia, while those with Wernicke\`s aphasia show contrary symptoms: they are able to pronounce words correctly, but cannot understand what the words mean. That is why they often utter phonologically correct words (neologisms) that are not real words with a meaning. Syntax Syntax describes the rules of how words must be arranged to result in meaningful sentences. Humans in general usually know the syntax of their mother tongue and thus slip their tongue if a word happens to be out of order in a sentence. People with aphasia, however, often have problems with parsing of sentences, not only with respect to the production of language but also with respect to comprehension of sentences. Patients showing an inability of comprehension and production of sentences usually have some kind of anterior aphasia, also called agrammatical aphasia. This can be revealed in tests with sentences. These patients cannot distinguish between active and passive voice easily if both agent and object could play an active part. For example patients do not see a difference between "The boy chased the girl" and "The boy was chased by the girl", but they do understand both "The boy saw the apple" and "The apple was seen by the boy", because they can seek help of semantics and do not have to rely on syntax alone. Patients with posterior aphasia, like for example Wernicke\`s aphasia, do not show these symptoms, as their speech is fluent. Comprehension by mere syntactic means would be possible as well, but the semantic aspect must be considered as well. This will be discussed in the next part. Semantics Semantics deals with the meaning of words and sentences. It has been shown that patients suffering from posterior aphasia have severe problems understanding simple texts, although their knowledge of syntax is intact. The semantic shortcoming is often examined by a Token Test, a test in which patients have to point to objects referred to in simple sentences. As might have been guessed, people with anterior aphasia have no problems with semantics, yet they might not be able to understand longer sentences because the knowledge of syntax then is involved as well. ```{=html} <center> ``` --------------- ----------------------------------------------- --------------------------------------- anterior Aphasia (e.g. Broca) posterior Aphasia (e.g. Wernicke) Phonology phonetic and phonemic representation affected phonemic representation affected Syntax affected no effect Syntax no effect affected --------------- ----------------------------------------------- --------------------------------------- `<small>`{=html}Overview of the effects of aphasia from the psychological perspective`</small>`{=html} ```{=html} </center> ``` In general studies with lesioned people have shown that anterior areas are needed for speech output and posterior regions for speech comprehension. As mentioned above anterior regions are also more important for syntactic processing, while posterior regions are involved in semantic processing. But such a strict division of the parts of the brain and their responsibilities is not possible, because posterior regions must be important for more than just sentence comprehension, as patients with lesions in this area can neither comprehend nor produce any speech. (Barnich, 1997, pp. 283--293) ### Evidence from Advanced Neuroscience Methods Measuring the functions of both normal and damaged brains has been possible since the 1970s, when the first brain imaging techniques were developed. With them, we are able to "watch the brain working" while the subject is e.g. listening to a joke. These methods (further described in chapter 4) show whether the earlier findings are correct and precise. Generally, imaging shows that certain functional brain regions are much smaller than estimated in brain lesion studies, and that their boundaries are more distinct (cf. Banich p. 294). The exact location varies individually, therefore bringing the results of many brain lesion studies together caused too big estimated functional regions before. For example, stimulating brain tissue electrically (during epilepsy surgery) and observing the outcome (e.g. errors in naming tasks) led to a much better knowledge where language processing areas are located. PET studies (Fiez & Petersen, 1993, as cited in Banich, p. 295) have shown that in fact both anterior and posterior regions were activated in language comprehension and processing, but with different strengths -- in agreement with the lesion studies. The more active speech production is required in experiments, the more frontal is the main activation: For example, when the presented words must be repeated. Another result (Raichle et al. 1994, as referred to in Banich, p. 295) was that the familiarity of the stimuli plays a big role. When the subjects were presented well-known stimuli sets in well-known experimental tasks and had to repeat them, anterior regions were activated. Those regions were known to cause conduction aphasia when damaged. But when the words were new ones, and/or the subjects never had to do a task like this before, the activation was recorded more posterior. That means, when you repeat an unexpected word, the heaviest working brain tissue is about somewhere under your upper left earlap, but when you knew this word that would be the next to repeat before, it is a bit nearer to your left eye. ## Visual Language Processing The processing of written language is performed when we are reading or writing and is thought to happen in a distinct neural processing unit than auditory language processing. Reading and writing respectively rely on vision whereas spoken language is first mediated by the auditory system. Language systems responsible for written language processing have to interact with a sensory system different from the one involved in spoken language processing. Visual language processing in general begins when the visual forms of letters ("c" or "C" or "c") are mapped onto abstract letter identities. These are then mapped onto a word form and the corresponding semantic representation (the "meaning" of the word, i.e. the concept behind it). Observations of patients that lost a language ability due to a brain damage led to different disease patterns that indicated a difference between perception (reading) and production (writing) of visual language just like it is found in non-visual language processing. Alexic patients possess the ability to write while not being able to read whereas patients with agraphia are able to read but cannot write. Though alexia and agraphia often occur together as a result of damage to the angular gyrus, there were patients found having alexia without agraphia (e.g. Greenblatt 1973, as cited in M. T. Banich, "Neuropsychology", p. 296) or having agraphia without alexia (e.g. Hécaen & Kremin, 1976, as cited in M. T. Banich, "Neuropsychology", p. 296). This is a double dissociation that suggests separate neural control systems for reading and writing. Since double dissociations are also found in phonological and surface dyslexia, experimental results support the theory that language production and perception respectively are subdivided into separate neural circuits. The two route model shows how these two neural circuits are believed to provide pathways from written words to thoughts and from thoughts to written words. ### Two routes model !1.1. Each route derives the meaning of a word or the word of a meaning in a different way{width="395"}In essence, the two routes model contains two routes. Each of them derives the meaning of a word or the word of a meaning in a different way, depending on how familiar we are with the word. Using the phonological route means having an intermediate step between perceiving and comprehending of written language. This intermediate step takes places when we are making use of grapheme-to-phoneme rules. Grapheme-to-phoneme rules are a way of determining the phonological representation for a given grapheme. A grapheme is the smallest written unit of a word (e.g. "sh" in "shore") that represents a phoneme. A phoneme on the other hand is the smallest phonological unit of a word distinguishing it from another word that otherwise sounds the same (e.g. "bat" and "cat"). People learning to read or are encountering new words often use the phonological route to arrive at a meaning representation. They construct phonemes for each grapheme and then combine the individual phonemes to a sound pattern that is associated with a certain meaning (see 1.1). The direct route is supposed to work without an intermediate phonological representation, so that print is directly associated with word-meaning. A situation in which the direct route has to be taken is when reading an irregular word like "colonel". Application of grapheme-to-phoneme rules would lead to an incorrect phonological representation. According to Taft (1982, as referred to in M. T. Banich,"Neuropsychology", p. 297) and others the direct route is supposed to be faster than the phonological route since it does not make use of a "phonological detour" and is therefore said to be used for known words ( see 1.1). However, this is just one point of view and others, like Chastain (1987, as referred to in M. T. Banich, "Neuropsychology", p. 297), postulate a reliance on the phonological route even in skilled readers. ### The processing of written language in reading !1.2. Regularity effects are common in cases of surface alexia{width="353"}Several kinds of alexia could be differentiated, often depending on whether the phonological or the direct route was impaired. Patients with brain lesions participated in experiments where they had to read out words and non-words as well as irregular words. Reading of non-words for example requires access to the phonological route since there cannot be a "stored" meaning or a sound representation for this combination of letters. Patients with a lesion in temporal structures of the left hemisphere (the exact location varies) suffer from so called surface alexia. They show the following characteristic symptoms that suggest a strong reliance on the phonological route: Very common are regularity effects, that is a mispronunciation of words in which the spelling is irregular like \"colonel\" or \"yacht\" (see 1.2). These words are pronounced according to grapheme-to-phoneme rules, although high-frequency irregularly spelled words may be preserved in some cases, the pronunciation according to the phonological route is just wrong. Furthermore, the would-be pronunciation of a word is reflected in reading-comprehension errors. When asked to describe the meaning of the word "bear", people suffering from surface alexia would answer something like "a beverage" because the resulting sound pattern of "bear" was the same for these people as that for "beer". This characteristic goes along with a tendency to confuse homophones (words that sound the same but are spelled differently and have different meanings associated). However, these people are still able to read non-words with a regular spelling since they can apply grapheme-to-phoneme rules to them. !1.3. Patients with phonological alexia have to rely on the direct route{width="353"}In contrast, phonological alexia is characterised by a disruption in the phonological route due to lesions in more posterior temporal structures of the left hemisphere. Patients can read familiar regular and irregular words by making use of stored information about the meaning associated with that particular visual form (so there is no regularity effect like in surface alexia). However, they are unable to process unknown words or non-words, since they have to rely on the direct route (see 1.3). Word class effects and morphological errors are common, too. Nouns, for example, are read better than function words and sometimes even better than verbs. Affixes which do not change the grammatical class or meaning of a word (inflectional affixes) are often substituted (e.g. "farmer" instead of "farming"). Furthermore, concrete words are read with a lower error rate than abstract ones like "freedom" (concreteness effect). Deep Alexia shares many symptomatic features with phonological alexia such as an inability to read out non-words. Just as in phonological alexia, patients make mistakes on word inflections as well as function words and show visually based errors on abstract words ("desire" → "desert"). In addition to that, people with deep alexia misread words as different words with a strongly related meaning ("woods" instead of "forest"), a phenomenon referred to as semantic paralexia. Coltheart (as referred to in the "Handbook of Neurolinguistics", ch.41-3, p. 563) postulates that reading in deep dyslexia is mediated by the right hemisphere. He suggests that when large lesions affecting language abilities other than reading prevent access to the left hemisphere, the right-hemispheric language store is used. Lexical entries stored there are accessed and used as input to left-hemisphere output systems. !Overview alexia{width="622"} ### The processing of written language in spelling !The phonological route is supposed to make use of phoneme-to-grapheme rules while the direct route links thought to writing without an intermediary phonetic representation{width="365"}Just like in reading, two separate routes --a phonological and a direct route- are thought to exist. The phonological route is supposed to make use of phoneme-to-grapheme rules while the direct route links thought to writing without an intermediary phonetic representation (see 1.4). It should be noted here that there is a difference between phoneme-to-grapheme rules (used for spelling) and grapheme-to-phoneme rules in that one is not simply the reverse of the other. In case of the grapheme "k" the most common phoneme for it is /k/. The most common grapheme for the phoneme /k/, however, is "c". Phonological agraphia is caused by a lesion in the left supramarginal gyrus, which is located in the parietal lobe above the posterior section of the Sylvian fissure (M. T. Banich, "Neuropsychology", p. 299). The ability to write regular and irregular words is preserved while the ability to write non-words is not. This, together with a poor retrieval of affixes (which are not stored lexically), indicates an inability to associate spoken words with their orthographic form via phoneme-to-grapheme rules. Patients rely on the direct route, which means that they use orthographic word-form representations that are stored in lexical memory. Lesions at the conjunction of the posterior parietal lobe and the parieto-occipital junction cause so called lexical agraphia that is sometimes also referred to as surface agraphia. As the name already indicates, it parallels surface alexia in that patients have difficulty to access lexical-orthographic representations of words. Lexical agraphia is characterised by a poor spelling of irregular words but good spelling for regular and non-words. When asked to spell irregular words, patients often commit regularization errors, so that the word is spelled phonologically correct (for example, "whisk" would be written as "wisque"). The BEST to CONNECT is to CAPITALISE the WORDS you WANT TO COMMUNICATE for readers to COMPREHEND. !Overview agraphia{width="581"} ### Evidence from Advanced Neuroscience Methods How can we find evidence for the theory of the two routes. Until now neuroscientific research is not able to ascertain that there are neural circuits representing a system like the one described above. The problem of finding evidence for visual language processing on two routes in contrast to one route ( as stated by e.g. from Seidenberg & McClelland as referred to in M. T. Banich,"Neuropsychology", p. 308) is that it is not clear what characteristic brain activation would indicate that it is either happening on two or one routes. To investigate whether there are one or two systems, neuroimaging studies examine correlations between the activations of the angular gyrus, which is thought to be a crucial brain area in written language processing and other brain regions. It was found out that during reading of non- words ( which would strongly engage the phonological route) the activation is mostly correlated with brain regions which are involved in phonological processing e.g. superior temporal regions (BA 22) and Boca's area. During reading of normal words (which would strongly engage the direct route) the highest activation was found in occipital and ventral cortex. That at least can imply that there are two distinct routes. However, these are conclusions drawn from highest correlations which do not ensure this suggestion. What neuroimaging studies do ascertain is that the usage of a phonological and a direct route strongly overlap, which is rather unspectacular since it is quiet reasonable that fluent speaker mix both of the routes. Other studies additionally provide data in which the activated brain regions during reading of non-words and reading of normal words differ. ERP studies suggest that the left hemisphere possesses some sort mechanism which response to combinations of letters in a string, or to its orthography and / or to the phonological representation of the string. ERP waves differ, during early analysis of the visual form of the string, if the string represents a correct word or just pronounceable nonsense (Posner & McCandliss, 1993 as referred in M.T. Banich, „Neuropsychology"p. 307-308). That indicates that this mechanism is sensitive to correct or incorrect words. The opposite hemisphere, the right hemisphere, is in contrast to the left hemisphere, not involved in abstract mapping of word meaning but is rather responsible for encoding word specific visual forms. ERP and PET studies provides evidence that the right hemisphere responds in a stronger manner than the left hemisphere to letter like strings. Moreover divided visual field studies reveal that the right hemisphere can better distinguish between different shapes of the same letter (e.g. in different handwritings) than the left hemisphere. The contribution of visual language processing on both hemispheres is that the right hemisphere first recognizes a written word as letter sequences, no matter how exactly they look like, then the language network in the left hemisphere builds up an abstract representation of the word, which is the comprehension of the word. ## Other symbolic systems Most neurolinguistic research is concerned with production and comprehension of English language, either written or spoken. However, looking at different language systems from a neuroscientific perspective can substantiate as well as differentiate acknowledged theories of language processing. The following section shows how neurological research of three symbolic systems, each different from English in some aspect, has made it possible to distinguish - at least to some extent - between brain regions that deal with the modality of the language (and therefore may vary from language to language, depending on whether the language in question is e.g. spoken or signed) from brain regions that seem to be necessary to language processing in general - regardless whether we are dealing with signed, spoken, or even musical language. ### Kana and Kanji Kana and Kanji are the two writing systems used parallel in the Japanese language. Since different approaches are used in them to represent words, studying Japanese patients with alexia is a great possibility to test the hypothesis about the existence of two different routes to meaning, explicated in the previous section. The English writing system is phonological -- each grapheme in written English roughly represents one speech sound -- a consonant or a vowel. There are, however, other possible approaches to writing down a spoken language. In syllabic systems like the Japanese kana, one grapheme stands for one syllable. If written English were syllabic, it could e.g. include a symbol for the syllable "nut", appearing both in the words "donut" and "peanut". Syllabic systems are sound-based -- since the graphemes represent units of spoken words rather than meaning directly, an auditory representation of the word has to be created in order to arrive at the meaning. Therefore, reading of syllabic systems should require an intact phonological route. In addition to kana, Japanese also use a logographic writing system called kanji, in which one grapheme represents a whole word or a concept. Different from phonological and syllabic systems, logographic systems don't comprise systematical relationships between visual forms and the way they're pronounced -- instead, visual form is directly associated with the pronunciation and meaning of the corresponding word. Reading kanji should therefore require the direct route to meaning to be intact. The hypothesis about the existence of two different routes to meaning has been confirmed by the fact that after brain damage, there can be a double dissociation between kana and kanji. Some Japanese patients can thus read kana but not kanji (surface alexia), whereas other can read kanji but not kana (phonological alexia). In addition, there is evidence that different brain regions of Japanese native speakers are active while reading kana and kanji, although like in the case of English native speakers, these regions also overlap. Since the distinction between direct and phonological route also makes sense in case of Japanese, it may be a general principle common to all written languages that reading them relies on two independent (at least partially) systems, both using different strategies to catch the meaning of a written word -- either associating the visual form directly with the meaning (the direct route), or using the auditory representation as an intermediary between the visual form and the meaning of the word (the phonological route). ```{=html} <center> ``` ----------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- !The Japanese Kana sign for the syllable \"mu\" !The Japanese Kanji sign for the concept \"Book\", \"writing\", or \"calligraphy ----------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ```{=html} </center> ``` ### Sign Language From a linguistic perspective, sign languages share many features of spoken languages -- there are many regionally bounded sign languages, each with a distinct grammar and lexicon. Since at the same time, sign languages differ from spoken languages in the way the words are "uttered", i.e. in the modality, neuroscientific research in them can yield valuable insights into the question whether there are general neural mechanisms dealing with language, regardless of its modality. Structure of SL Sign languages are phonological languages - every meaningful sign consists of several phonemes (phonemes used to be called cheremes (Greek χερι: hand) until their cognitive equivalence to phonemes in spoken languages was realized) that carry no meaning as such, but are nevertheless important to distinguish the meaning of the sign. One distinctive feature of SL phonemes is the place of articulation -- one hand shape can have different meanings depending on whether it's produced at the eye-, nose-, or chin-level. Other features determining the meaning of a sign are hand shape, palm orientation, movement, and non-manual markers (e.g. facial expressions). To express syntactic relationships, Sign Languages exploit the advantages of the visuo-spatial medium in which the signs are produced -- the syntactic structure of sign languages therefore often differs from that of spoken languages. Two important features of most sign language\'s grammars (including American Sign Language (ASL), Deutsche Gebärdensprache (DGS) and several other major sign languages) are directionality and simultaneous encoding of elements of information: - Directionality The direction in which the sign is made often determines the subject and the object of a sentence. Nouns in SL can be \'linked\' to a particular point in space, and later in the discourse they can be referred to by pointing to that same spot again (this is functionally related to pronouns in English). The object and the subject can then be switched by changing the direction in which the sign for a transitive verb is made. - Simultaneous encoding of elements of information The visual medium also makes it possible to encode several pieces of information simultaneously. Consider e.g. the sentence \"The flight was long and I didn\'t enjoy it\". In English, the information about the duration and unpleasantness of the flight have to be encoded sequentially by adding more words to the sentence. To enrich the utterance \"The flight was long" with the information about the unpleasantness of the flight, another sentence ("I did not enjoy it\") has to be added to the original one. So, in order to convey more information, the length of the original sentence must grow. In sign language, however, the increase of information in an utterance doesn't necessarily increase the length of the utterance. To convey information about the unpleasantness of a long flight experienced in the past, one can just use the single sign for \"flight\" with the past tense marker, moved in a way that represents the attribute \"long\", combined with the facial expression of disaffection. Since all these features are signed simultaneously, no additional time is needed to utter \"The flight was long\" as compared to \"The flight was long and I didn\'t enjoy it\". Neurology of SL Since sentences in SL are encoded visually, and since its grammar is often based on visual rather than sequential relationships among different signs, it could be suggested that the processing of SL mainly depends on the right hemisphere, which is mainly concerned with the performance on visual and spatial tasks. However, there is evidence suggesting that processing of SL and spoken language might be equally dependant on the left hemisphere, i.e. that the same basic neural mechanism may be responsible for all language functioning, regardless of its modality (i.e. whether the language is spoken or signed). The importance of the left hemisphere in SL processing indicated e.g. by the fact that signers with a damaged right hemisphere may not be aphasiacs, whereas as in case of hearing subjects, lesions in the left hemisphere of signers can result in subtle linguistic difficulties (Gordon, 2003). Furthermore, studies of aphasic native signers have shown that damage to anterior portions of the left hemisphere (Broca's area) result in a syndrome similar to Broca's aphasia -- the patients lose fluency of communication, they aren't able to correctly use syntactic markers and inflect verbs, although the words they sign are semantically appropriate. In contrast, patients with damages to posterior portions of the superior temporal gyrus (Wernicke's area) can still properly inflect verbs, set up and retrieve nouns from a discourse locus, but the sequences they sign have no meaning (Poizner, Klima & Bellugi, 1987). So, like in the case of spoken languages, anterior and posterior portions of the left hemisphere seem to be responsible for the syntax and semantics of the language respectively. Hence, it's not essential for the \"syntax processing mechanisms\" of the brain whether the syntax is conveyed simultaneously through spatial markers or successively through word order and morphemes added to words - the same underlying mechanisms might be responsible for syntax in both cases. Further evidence for the same underlying mechanisms for spoken and signed languages comes from studies in which fMRI has been used to compare the language processing of: - 1\. congenitally deaf native signers of British Sign Language, - 2\. hearing native signers of BSL (usually hearing children of deaf parents) - 3\. hearing signers who have learned BSL after puberty - 4\. non-signing subjects Investigating language processing in these different groups allows making some distinctions between different factors influencing language organization in the brain - e.g. to what amount does deafness influences the organization of language in the brain as compared to just having SL as a first language(1 vs. 2), or to what amount does learning of SL as a first language differ from learning SL as native language(1,2 vs.3), or to what amount is language organized in speakers as compared to signers(1,2,3 vs.4). These studies have shown that typical areas in the left hemisphere are activated in both native English speakers given written stimuli and native signers given signs as stimuli. Moreover, there are also areas that are equally activated both in case of deaf subjects processing sign language and hearing subjects processing spoken language -- a finding which suggests that these areas constitute the core language system regardless of the language modality(Gordon, 2003). Different from speakers, however, signers also show a strong activation of the right hemisphere. This is partly due to the necessity to process visuo-spatial information. Some of those areas, however (e.g. the angular gyrus) are only activated in native signers and not in hearing subjects that learned SL after puberty. This suggests that the way of learning sign languages (and languages in general) changes with time: Late learner\'s brains are unable to recruit certain brain regions specialized for processing this language (Newman et al., 1998).\] We have seen that evidence from aphasias as well as from neuroimaging suggest the same underlying neural mechanisms to be responsible for sign and spoken languages. It 's natural to ask whether these neural mechanisms are even more general, i.e. whether they are able to process any type of symbolic system underlying some syntax and semantics. One example of this kind of more general symbolic system is music. ### Music Like language, music is a human universal involving some combinatorial principles that govern the organizing of discrete elements (tones) into structures (phrases) that convey some meaning -- music is a symbolic system with a special kind of syntax and semantics. It's therefore interesting to ask whether music and natural language share some neural mechanisms: whether processing of music is dependent on processing of language or the other way round, or whether the underlying mechanisms underlying them are completely separate. By investigating the neural mechanisms underlying music we might find out whether the neural processes behind language are unique to the domain of natural language, i.e. whether language is modular. Up to now, research in the neurobiology of music has yielded contradicting evidence regarding these questions. On the one hand, there is evidence that there is a double dissociation of language and music abilities. People suffering from amusia are unable to perceive harmony, to remember and to recognize even very simple melodies; at the same time they have no problems in comprehending or producing speech. There is even a case of a patient who developed amusia without aprosodia, i.e. although she couldn\'t recognize tone in musical sequences, she nevertheless could still make use of pitch, loudness, rate, or rhythm to convey meanings in spoken language (Pearce, 2005). This highly selective problem in processing music (amusia) can occur as a result of brain damage, or be inborn; in some cases it runs on families, suggesting a genetic component. The complement syndrome of amusia also exists -- after suffering a brain damage in the left hemisphere, the Russian composer Shebalin lost his speech functions, but his musical abilities remained intact (Zatorre, McGill, 2005). On the other hand, neuroimaging data suggest that language and music have a common mechanism for processing syntactical structures. The P600 ERP\`s in the Broca area, measured as a response to ungrammatical sentences, is also elicited in subjects listening to musical chord sequences lacking harmony (Patel, 2003) -- the expectation of typical sequences in music could therefore be mediated by the same neural mechanisms as the expectation of grammatical sequences in language. A possible solution to this apparent contradiction is the dual system approach (Patel, 2003) according to which music and language share some procedural mechanisms (frontal brain areas) responsible for processing the general aspects of syntax, but in both cases these mechanisms operate on different representations (posterior brain areas) -- notes in case of music and words in case of language. ## Outlook Many questions are to be answered, for it is e.g. still unclear whether there is a distinct language module (that you could cut out without causing anything in other brain functions) or not. As Evely C. Ferstl points out in her review, the next step after exploring distinct small regions responsible for subtasks of language processing will be to find out how they work together and build up the language network. ## References & Further Reading ` ` Books - english - Brigitte Stemmer, Harry A. Whitaker. Handbook of Neurolinguistics. Academic Press (1998). - Marie T. Banich: Neuropsychology. The neural bases of mental function (1997). - Ewa Dąbrowska: Language, Mind and Brain. Edinburgh University press Ltd.(2004) - a review: Evelyn C. Ferstl, The functional neuroanatomy of text comprehension. What\'s the story so far?\" from: Schmalhofer, F. & Perfetti, C. A. (Eds.), Higher Level Language Processes in the Brain:Inference and Comprehension Processes. Lawrence Erlbaum. (2004) Books - german - Müller,H.M.& Rickert,G. (Hrsg.): Neurokognition der Sprache. Stauffenberg Verlag (2003) - Poizner, Klima & Bellugi: What the hands reveal about the brain. MIT Press (1987) - N. Chomsky: Aspects of the Theory of Syntax. MIT Press (1965). - Neville & Bavelier: Variability in the effects of experience on the development of cerebral specializations: Insights from the study of deaf individuals. Washington, D.C.: US Government Printing Office (1998) - Newman et al.: Effects of Age of Acquisition on Cortical Organization for American Sign Language: an fMRI Study. NeuroImage, 7(4), part 2 (1998) Links - english - Robert A. Mason and Marcel Adam Just: How the Brain Processes Causal Inferences in Text - Neal J. Pearlmutter and Aurora Alma Mendelsohn: Serial versus Parallel Sentence Comprehension - Brain Processes of Relating a Statement to a Previously Read Text: Memory Resonance and Situational Constructions - Clahsen, Harald: Lexical Entries and Rules of Language: A Multidisciplinary Study of German Inflection. - Cherney, Leora (2001): Right Hemisphere Brain Damage - Grodzinsky, Yosef (2000): The neurology of syntax: Language use without Broca\'s area. - Müller, H.M. & Kutas, M. (1996). What\'s in a name? Electrophysiological differences between spoken nouns, proper names and one\'s own name. NeuroReport 8:221-225. - Müller, H. M., King, J. W. & Kutas, M. (1997). Event-related potentials elicited by spoken relative clauses Cognitive Brain Research 4:193-203. Links - german - University of Bielefeld: - Müller, H. M., Weiss, S. & Rickheit, G. (1997). Experimentelle Neurolinguistik: Der Zusammenhang von Sprache und Gehirn In: Bielefelder Linguistik (Hrsg.) Aisthesis-Verlag, pp. 125--128. - Müller, H.M. & Kutas, M. (1997). Die Verarbeitung von Eigennamen und Gattungsbezeichnungen: Eine elektrophysiologische Studie. In: G. Rickheit (Hrsg.). Studien zur Klinischen Linguistik - Methoden, Modelle, Intervention. Opladen: Westdeutscher Verlag, pp. 147--169. - Müller, H.M., King, J.W. & Kutas, M. (1998). Elektrophysiologische Analyse der Verarbeitung natürlichsprachlicher Sätze mit unterschiedlicher Belastung des Arbeitsgedächtnisses. Klinische Neurophysiologie 29: 321-330. ```{=html} <!-- --> ``` - Michael Schecker (1998): Neuronale \"Kodierung\" zentraler Sprachverarbeitungsprozesse \--\> Debates (only a criticism) ### Organizational Issues Group Members 2007 - send eMail to all - dberndt - phenk - tgeishau - bschledd Group Members 2006 - send eMail to all - jbuergle - maebert - hknepper - hnasir - npraceju - msumpf
# Cognitive Psychology and Cognitive Neuroscience/Situation Models and Inferencing +:------------------------------+:----:+------------------------------:+ \| Previous \| O \| [Next \| \| Chapter \| \| ext_Comprehension "wikilink") \| niti \| \| \| \| ve_P \| \| \| \| sych \| \| \| \| olog \| \| \| \| y_an \| \| \| \| d_Co \| \| \| \| gnit \| \| \| \| ive_ \| \| \| \| Neur \| \| \| \| osci \| \| \| \| ence \| \| \| \| "wi \| \| \| \| kili \| \| \| \| nk") \| \| +-------------------------------+------+-------------------------------+ ## Introduction An important function and property of the human cognitive system is the ability to extract important information out of textually and verbally described situations. This ability plays a vital role in understanding and remembering. But what happens to this information after it is extracted, how do we represent it and how do we use it for inferencing? With this chapter we introduce the concept of a "situation model" (van Dijk&Kintsch, 1983, "mental model": Johnson-Laird, 1983), which is the mental representation of what a text is about. We discuss what these representations might look like and show the various experiments that try to tackle these questions empirically. By assuming situations to be encoded by perceptual symbols (Barsalou, 1999), the theory of Situation Models touches many aspects of Cognitive Philosophy, Linguistics and Artificial Intelligence. In the beginning of this chapter, we will mention why Situation Models are important and what we use them for. Next we will focus on the theory itself by introducing the four primary types of information - the situation model components, its Levels of Representation and finally two other basic types of knowledge used in situation model construction and processing (general world knowledge and referent specific knowledge). Situation models not only form a central concept in theories of situated cognition that helps us in understanding how situational information is collected and how new information gets integrated, but they can also explain many other phenomena. According to van Dijk & Kintsch, situation models are responsible for processes like domain-expertise, translation, learning from multiple sources or completely understanding situations just by reading about them. These situation models consist, according to most researches in this area, of five dimensions, which we will explain later. When new information concerning one of these dimensions is extracted, the situation model is changed according to the new information. The bigger the change in the situation model is, the more time the reader needs for understanding the situation with the new information. If there are contradictions, e.g. new information which does not fit into the model, the reader fails to understand the text and probably has to reread parts of the text to build up a better model. It was shown in several experiments that it is easier to understand texts that have only small changes in the five dimensions of text understanding. It also has been found that it is easier for readers to understand a text if the important information is more explicitly mentioned. For this reason several researchers wrote about the importance of fore-grounding important information (see Zwaan&Radvansky 1998 for a detailed list). The other important issue about situation models is the multidimensionality. Here the important question is how are the different dimensions related and what is their weight for constructing the model. Some researchers claim that the weight of the dimensions shifts according to the situation which is described. Introducing such claims will be the final part of this chapter and aims to introduce you to current and future research goals. #### The VIP: Rolf A. Zwaan Rolf A. Zwaan, born September 13, 1962 in Rotterdam (the Netherlands), is a very important person for this topic, since he made the most research (92 publications in total), and also because most of our data is taken from his work. Zwaan did his MA (1986) and his Ph.D. (1992) at the Utrecht University (Netherlands), both cum laude. Since then he collected multiple awards like the Developing Scholar Award (Florida state University, 1999) or the Fellow of the Hanse Institute for Advanced Study (Delmenhorst, Germany, 2003) and became member of several Professional Organisations like the Psychonomic Society, the Cognitive Science Society or the American Psychological Society. He works as Chair of the Biology & Cognitive Psychology at the Erasmus University in Rotterdam (Netherlands), since 2007. ## Why do we need situation models? A lot of tasks which are based on language processing can only be explained by the usage of situation models. The so called situation model or mental model consists of five different dimensions, which refer to different sources. To comprehend a text or just a simple sentence, situation models are useful. Furthermore the comprehension and combination of several texts and sentences can be explained by that theory much better. In the following, some examples are listed why we really need situation models. #### Integration of information across sentences Integration of information across sentences is more than just understanding a set of sentences. For example: "Gerhard Schroeder is in front of some journalists. Looking forward to new ideas is nothing special for the Ex-German chancellor. It is like in the good old days in 1971 when the leader of the Jusos was behind the polls and talked about changes." This example only makes sense to the reader if he is aware that "Gerhard Schroeder", "Ex-German chancellor" and "the leader of the Jusos in 1971" is one and the same person. If we build up a situation model, in this example "Gerhard Schroeder" is our token. Every bit of information which comes up will be linked to this token, based on grammatical and world knowledge. The definite article in the second sentence refers to the individual in the first sentence. This is based on grammatical knowledge. Every definite article indicates a connection to an individual in a previous sentence. If there would be an indefinite article, we have to build a new token for a new individual. The third sentence is linked by domain knowledge to the token. It has to be known that "Gerhard Schroeder" was the leader of the Jusos in 1971. Otherwise the connection can only be guessed. We can see that an integrated situation model is needed to comprehend the connection between the three sentences. #### Explanation of similarities in comprehension performances across modalities The explanation of similarities in comprehension performances across modalities can only be done by the usage of situation models. If we read a newspaper article, watch a report on television or listen to a report on radio, we come up with a similar understanding of the same information, which is conveyed through different modalities. Thus we create a mental representation of the information or event. This mental representation does not depend on the modalities itself. Furthermore there is empirical evidence for this intuition. Baggett (1979) found out that students who saw a short film and students who heard a spoken version of the events in the short film finally produced a structurally similar recall protocol. There were differences in the protocols of the two groups but the differences were due to content aspects. Like the text version explicitly stated that a boy was on his way to school and in the movie this had to be inferred. #### Domain expertise on comprehension Situation models have a deep influence for effects of domain expertise on comprehension. In detail this means that person A, whose verbal skills are less than from person B, is able to outperform person B, if he has more knowledge of the topic domain. To give evidence for this intuition, there was a study by Schneider and Körkel (1989). They compared the recalls of "experts" and novices of a text about a soccer match. In the study were three different grades: 3rd, 5th and 7th. One important example in that experiment was that the 3rd grade soccer experts outperformed the 7th grade novices. The recall of units in the text was 54% by the 3rd grade experts and 42% by the 7th grade novices. The explanation is quite simple: The 3rd grade experts built up a situation model and used knowledge from their long-term memory (Ericsson & Kintsch, 1995). The 7th grade novices had just the text by which they can come up with a situation model. Some more studies show evidence for the theory that domain expertise may counteract with verbal ability, i.e. Fincher-Kiefer, Post, Greene & Voss, 1988 or Yekovich, Walker, Ogle & Thompson in 1990. #### Explanation of translation skills An other example why we need situation models is by trying to explain translation. Translating a sentence or a text from one language to another is not simply done by translating each word and building a new sentence structure until the sentence seems to be sound. If we have a look now at the example of a Dutch sentence: ![{width="450"} Now we can conclude that the translation level between Dutch and English is not based on the lexical-semantic level; it is based on the situation level. In this example "don't do something (action) before you haven't done something else (another action)". Other studies came up with findings that the ability to construct situation models during the translation is important for the translation skill (Zwann, Ericsson, Lally and Hill, in 1998). #### Multiple source learning People are able to learn about a domain from multiple documents. This phenomenon can be explained by a situation model, too. For example, we try to learn something about the "Cold War" we use different documents with information. The information in one document may be similar to other documents. Referents can be the same or special relationships in the "Cold War" can just be figured out by the usage of different documents. So what we are really doing by learning and reasoning is that we integrate information on the base of different documents into a common situation model, which has got an organized order of the information we've learned. We have seen that we need situation models in different tasks of language processing, but situation models are not needed in all tasks of language processing. An example is proofreading. A proofreader checks every word for its correctness. This ability does not contain the ability to construct situation models. This task uses the resources of the long-term memory in which the correct writing of each word is stored. The procedure is like: !Zwaan (2003{width="400"} This is done word by word. It is unnecessary to create situation models in this task for language processing. ## Multidimensionality of Situation Models ### Space Very often, objects that are spatially close to us are more relevant than more distant objects. Therefore, one would expect the same for situation models. consistent with this idea, comprehenders are slower to recognise words denoting objects distant from a protagonist than those denoting objects close to the protagonist (Glenberg, Meyer & Lindem, 1987). When comprehenders have extensive knowledge of the spatial layout of the setting of the story (e.g., a building), they update their representations according to the location and goals of the protagonist. They have the fastest mental access to the room that the protagonist is currently in or is heading to. For example, they can more readily say whether or not two objects are in the same room if the room mentioned is one of these rooms than if it is some other room in the building (e.g., Morrow, Greenspan, & Bower, 1987). This makes perfect sense intuitively because these are the rooms that would be relevant to us if we were in the situation. People's interpretation of the meaning of a verb denoting movement of people or objects in space, such as to approach, depends on their situation models. For example, comprehenders interpret the meaning of approach differently in The tractor is just approaching the fence than in The mouse is just approaching the fence. Specifically, they interpret the distance between the figure and the landmark as being longer when the figure is large (tractor) compared with when it is small (mouse). The comprehenders' interpretation also depends on the size of the landmark and the speed of the figure (Morrow & Clark, 1988). Apparently, comprehenders behave as if they are actually standing in the situation, looking at the tractor or mouse approaching a fence. ### Time We assume by default that events are narrated in their chronological order, with nothing left out. Presumably this assumption exists because this is how we experience events in everyday life. Events occur to us in a continuous flow, sometimes in close succession, sometimes in parallel, and often partially overlapping. Language allows us to deviate from chronological order, however. For example, we can say, "Before the psychologist submitted the manuscript, the journal changed its policy." The psychologist submitting the manuscript is reported first, even though it was the last of the two events to occur. If people construct a situation model, this sentence should be more difficult to process than its chronological counterpart (the same sentence, but beginning with "After"). Recent neuroscientific evidence supports this prediction. Event-related brain potential (ERP) measurements indicate that "before" sentences elicit, within 300 ms, greater negativity than "after" sentences. This difference in potential is primarily located in the left anterior part of the brain and is indicative of greater cognitive effort (Münte, Schiltz, & Kutas, 1998). In real life, events follow each other seamlessly. However, narratives can have temporal discontinuities, when writers omit events not relevant to the plot. Such temporal gaps, typically signalled by phrases such as a few days later, are quite common in narratives. Nonetheless, they present a departure from everyday experience. Therefore, time shifts should lead to (minor) disruptions of the comprehension process. And they do. Reading times for sentences that introduce a time shift tend to be longer than those for sentences that do not (Zwaan, 1996). `All other things being equal, events that happened just recently are more accessible to us than events that happened a while ago. `\ `Thus, in a situation model, ``enter`` should be less accessible after ``An hour ago, John entered the building`` than after ``A moment ago, John entered the building``. `\ `Recent probe-word recognition experiments support this prediction (e.g., Zwaan, 1996).` ### Causation As we interact with the environment, we have a strong tendency to interpret event sequences as causal sequences. It is important to note that, just as we infer the goals of a protagonist, we have to infer causality; we cannot perceive it directly. Singer and his colleagues (e.g., Singer, Halldorson, Lear, & Andrusiak, 1992) have investigated how readers use their world knowledge to validate causal connections between narrated events. Subjects read sentence pairs, such as 1a and then 1b or 1a' and then 1b, and were subsequently presented with a question like 1c: (1a) Mark poured the bucket of water on the bonfire. (1a') Mark placed the bucket of water by the bonfire. (1b) The bonfire went out. (1c) Does water extinguish fire? Subjects were faster in responding to 1c after the sequence 1a-1b than after 1a'-1b. According to Singer, the reason for the speed difference is that the knowledge that water extinguishes fire was activated to validate the events described in 1a-1b. However, because this knowledge cannot be used to validate 1a'-1b, it was not activated when subjects read that sentence pair. ### Intentionality We are often able to predict people's future actions by inferring their intentionality, i.e. their goals. For example, when we see a man walking over to a chair, we assume that he wants to sit, especially when he has been standing for a long time. Thus, we might generate the inference "He is going to sit." Keefe and McDaniel (1993) presented subjects with sentences like After standing through the 3-hr debate, the tired speaker walked over to his chair (and sat down) and then with probe words (e.g., sat, in this case). Subjects took about the same amount of time to name sat when the clause about the speaker sitting down was omitted and when it was included. Moreover, naming times were significantly faster in both of these conditions than in a control condition in which it was implied that the speaker remained standing. ### Protagonists and Objects Comprehenders are quick to make inferences about protagonists, presumably in an attempt to construct a more complete situation model. Consider, for example, what happens after subjects read the sentence The electrician examined the light fitting. If the following sentence is She took out her screwdriver, their reading speed is slowed down compared with when the second sentence is He took out his screwdriver. This happens because she provides a mismatch with the stereotypical gender of an electrician, which the subjects apparently inferred while reading the first sentence (Carreiras, Garnham, Oakhill, & Cain, 1996). `Comprehenders also make inferences about the emotional states of characters. `\ `For example, if we read a story about Paul, who wants his brother Luke to be good in baseball, the concept of “pride” becomes activated in our mind when we read`\ `that Luke receives the Most Valuable Player Award (Gernsbacher, Goldsmith, & Robertson, 1992). `\ `Thus, just as in real life, we make inferences about people’s emotions when we comprehend stories.` ## Processing Frameworks ### Introduction In the process of language and text comprehension new information has to be integrated into the current situation model. This is achieved by a processing framework. There are various theories and insights on this process. Most of them only model one or some aspects of Situation Models and language comprehension. A list of theories, insights and developments in language comprehension frameworks: - an interactive model of comprehension (Kintsch and van Dijk, 1978) - early Computatinal Model (Miller, Kintsch, 1980) - Constructing-integration Model (Kintsch, 1988) - Structure-Building-Framework (Gernsbacher,1990) - Capacity Constraint Reader Model (Just, Carpenter, 1992) - Constructivist framework (Graesser, Singer, Trabasso, 1994) - Event Indexing Model (Zwaan, Langston, Graesser, 1995) - Landscape Model (van den Brock, Risden, Fletcher, & Thurlow, 1996) - Capacity-constrained construction-integration Model (Goldman, Varma, Coté, 1996) - The Immersed Experiencer Framework (Zwaan, 2003) In this part of the chapter on Situation Models we will talk about several models; we will start with some of the early stuff and then go to the popular later ones. We will start with the work of Kintsch in the 70s and 80s and then go on to later research which is based on this. ### An interactive Model of Comprehension This model was already developed in the 80s; it is the basis for many later models like the CI-Model, or even the Immersed-Experiencer Framework. According to Kintsch and van Dijk (1978), text comprehension proceeds in cycles. In every cycle a few propositions are processed, this number is determined by the capacity of the Short-Term Memory, so 7 plus or minus 2. In every cycle the new propositions are connected to existing ones, they therefore form a connected and hierarchical set. ### Early Computational Model This computational model from Miller and Kintsch tried to model earlier theories of comprehension, to make predictions according to these and compare them to behavioural studies and experiments. It consisted of several modules. One was a chunking program: It\'s task is to read in one word at the moment, identify if it is a proposition and decide whether to integrate it or not. This part of the model was not done computationally. The next part in the input order was the Microstructure Coherence Program (MCP). The MCP sorted the propositions and stored them in the Working Memory Coherence Graph. The task of the Working Memory Coherence Graph was then to decide which propositions should be kept active during the next processing cycle. All propositions are stored in the Long Term Memory Coherence Graph, this decided which propositions should be transferred back in to the Working Memory or it can construct a whole new Working Memory Graph with a different superordinate node. The problem with this Computational Model was that it show a really low performance. But still it led to further research which tried to overcome it\'s shortcomings. ### Event-Indexing Model The Event-Indexing Model was first proposed by Zwaan, Langston and Graesser (1995). It makes claims about how the incoming information in comprehension is processed and how it is represented in the long-term memory. According to the Event-Indexing Model all incoming actions events are split into five indexes. The five indexes are the same as the five situational dimensions, though Zwaan & Radvasnky(1998) claim that there are possibly more dimensions. These might be found in future research. One basic point of this model is the processing time of integrating new events into the current model. It is easier to integrate a new incoming event if it shares indexes with a previous event. The more contiguous the new event is, the easier it is integrated into the new Situation Model. This prediction made by Zwaan & Radvanksy (1998) is supported by some prior research (Zwaan, Magliano and Graesser, 1995). The other important point of the Event-Indexing Model is the representation in long-term memory. Zwaan & Radvasnky (1998) predict that this representation is a network of nodes, these nodes encode the events. The nodes are linked with each other through situational links according to the indexes they share. This connection does not only encode if two nodes share indexes but it also encodes the number of shared indexes through its strength. This second point already hints what the Event-Indexing Model lacks. There are several things which it does not include. For example it does not encode the temporal order of the events nor the direction of the causal relationships. The biggest disadvantage of the Event-Indexing Model is clearly that it treats the different dimensions as different entities though they probably interact with each other. Zwaan & Radvansky (1998) updated the Event-Indexing Model with some features. This new model splits the processed information into three types. These three types are the situational framework, the situational relations and the situational content. The situational framework grounds the situation in space and time, and its construction is obligatory. If no information is given this framework is probably built up by standard values retrieved from prior world knowledge or some empty variable would be instantiated. he situational relations are based on the five situational dimensions. These are analysed through the Event-Indexing Model. This kind of situational information includes not the basic information, which is given in the situational framework, but the relationships between the different entities or nodes in the network. In contrast to the situational framework the situational relations are not obligatory. If there is no information given or there are no possible inferences between entities, then there is simply no relationship there. There is also an index which addresses importance to the different relations. This importance consists of the necessity of the information to understand the situation, the easiness to inference it when it would not be mentioned and how easy the information can later be remembered. Another distinction this theory makes is the one between functional and non-functional relations (Carlson-Radvansky & Radvansky, 1996; Garrod & Sanford, 1989). Functional relations describe the interaction between different entities whereas non-functional relations are the ones between non-interacting entities. The situational content consists of the entities in the situation like protagonists and objects and their properties. These are only integrated explicitly in the Situation Model, like situational relations, if they are necessary for the understanding of the situation. Nonetheless the central and most important entities and their properties are obligatory again. It is proposed that, in order to keep the processing time low, non-essential information is only represented by something like a pointer so that this information can be retrieved if necessary. ### The Immersed Experiencer Framework The Immersed Experiencer Framework (IEF) is based on prior processing framework models (see above for a detailed list) but tries to include several other research findings too. For example it was found that during comprehension brain regions are activated, which are very close or even overlap with brain regions which are active during the perception or the action of the words meaning (Isenberg et al., 2000; Martin & Chao, 2001; Pulvermüller, 1999, 2002). During comprehension there is also a visual representation of shape and orientation of objects (Dahan & Tanenhaus, 2002; Stanfield & Zwaan, 2002; Zwaan et al., 2002; Zwaan & Yaxley, in press a, b). Visual-spatial information primes sentence processing (Boroditsky, 2000). These visual representations can interfer with the comprehension (Fincher-Kiefer, 2001). Findings from (Glenberg, Meyer, & Lindem, 1987; Kaup & Zwaan, in press; Morrow et al., 1987; Horton & Rapp, in press; Trabasso & Suh, 1993; Zwaan et al., 2000) suggest that information which is part of the situation and the text is more active in the reader\'s mind than information which is not included. The fourth research finding is that people move their eyes and hand during comprehension in a consistent way with the described the situation. (Glenberg & Kaschak, in press; Klatzky et al., 1989; Spivey et al., 2000). The main point of the Immersed Experiencer Framework is the idea that words active experiences with their referents. For example \"an eagle in the sky\" activates a visual experience of a eagle with stretched-out wings while \"an eagle in the nest\" activates a different visual experience. According to Zwaan (2003) the IEF should be seen as an engine to make predictions about language comprehension. These predictions are then suggested for further research. According to the IEF the process of language comprehension consists of three components, these are activation, construal and integration. Each component works at a different level. Activation works at the world level, construal is responsible for the clause level while integration is active at the discourse level. Though the IEF shares many points with earlier models of language comprehension it differs in some main points. For example it suggests that language comprehension involves action and perceptual representations and not amodal propositions (Zwaan, 2003). ## Levels of Representation in Language and Text Comprehension A lot of theories try to explain the situation model or so called mental model in different representations. Several theories of the representation deal with the comprehension from the text into the situation model itself. How many levels are included or needed and how is the situation model constructed, is it done by once like: Sentence → Situation Model Or are there levels in between which have to be passed until the model is constructed? Here are three different representations shown which try to explain the construction of the situation model by a text. #### Propositional Representation The propositional Representation claims that a sentence will be structured in another way and then it is stored. Included information does not get lost. We will have a look at the simple sentence: "George loves Sally" the propositional representation is \[LOVES(GEORGE, SALLY)\] It is easy to see that the propositional representation is easy to create and the information is still available. #### Three levels of representation !Fletcher(1994); van Dijk & Kintch(1983); Zwaan & Radvansky (1998); van Dijk & Kintch(1983); Zwaan & Radvansky (1998)"){width="150"} This theory says that there exist three levels of representation the surface form, text base and the situation model. In this example the sentence "The frog ate the bug." Is already the surface form. We naturally create semantically relations to understand the sentence (semantic tree in the figure). The next level is the "Text base". \[EAT(FROG, BUG)\] is the propositional representation and Text base is close to this kind of representation, except that it is rather spatial. Finally the situation model is constructed by the "Text base" representation. We can see that the situation model does not include any kind of text. It is a mental picture of information in the sentence itself. #### Two levels of representation !Frank Koppen, Nordman, Vonk (to appear) Zwaan (2004) Zwaan (2004)"){width="150"} This theory is like the "three levels of representations" theory. But the "Text base" level is left out. The theory itself claims that the situation model is created by the sentence itself and there is no "Text base" level needed. Further situation model theories directing experiences exist. So not only text comprehension is done by situation models, learning through direct experience is handled by situation models, too. #### KIWi-Model !A unified model by \"Prof. Dr.\" Schmalhofer{width="250"} One unified model the so called KIWi-Model tries to explain how text representation and direct experience interact with a situation model. Additionally the domain knowledge is integrated. The domain knowledge is used by forming a situation model in different tasks like simple sentence comprehension (chapter: Why do we need Situation Models). The KIWi-Model shows that a permanent interaction between "text representation → situation model" and between "sensory encoding → situation model" exists. These interactions supports the theory of a permanent updating of the mental model. ## Inferencing Inferencing is used to build up complex situation models with limited information. For example: in 1973 John Bransford and Marcia Johnson made a memory experiment in which they had two groups reading variations of the same sentence. The first group read the text \"John was trying to fix the bird house. He was pounding* the nail when his father came out to watch him do the work\" The second group read the text \"John was trying to fix the bird house. He was looking for the nail when his father came out to watch him do the work\" After reading, some test statements were presented to the participants. These statements contained the word hammer* which did not occur in the original sentences, e.g.: \"John was using a hammer to fix the birdhouse. He was looking for the nail when his father came out to watch him\". Participants of the first group said they had seen 57% of the test statements, while the participants from the second group had seen only 20% of the test statements. As one can see, in the first group there is a tendency of believing to have seen the word hammer. The participants of this group made the inference, that John used a hammer to pound the nail. This memory influence test is good example to get an idea what is meant by making inferences and how they are used to complete situation models. While reading a text, inferencing creates information which is not explicitly stated in the text; hence it is a creative process. It is very important for text understanding in general, because texts cannot include all information needed to understand the sense of a story. Texts usually leave out what is known as world knowledge. World knowledge is knowledge about situations, persons or items that most people share, and therefore don\'t need to be explicitly stated. Each person should be able to infer this kind of information, as for example that we usually use hammers to pound nails. It would be impossible to write a text, if it had to include all information it deals with; if there was no such thing like inferencing or if it was not automatically done by our brain. There is a number of different kinds of inferences: ### Anaphoric Inference This kind of Inferencing usually connects objects or persons from one to another sentence. Therefore it is responsible for connecting cross-sentence information. E.g. in \"John hit the nail. He was proud of his stroke\", we directly infer that \"he\" and \"his\" relate to \"John\". We normally make this kind of inference quite easily. But there can be sentences where more persons and other words relating to them are mixed up and people have problems understanding the story at first. This is normally regarded as bad writing style. ### Instrumental Inference This type of Inference is about the tools and the methods used in the text, like the hammer in the example above. Or for example, if you read about somebody flying to New York, you would not infer that this person has built a dragon-flyer and jumped off a cliff but that he or she used a plane, since there is nothing else mentioned in the text and a plane is the most common form of flying to New York. If there is no specific information about tools, instruments and methods, we get this information from our General World Knowledge ### Causal Inference Causal Inference is the conclusion that one event caused another in the text, like in \"He hit his nail. So his finger ached\". The first sentence gives the reason why the situation described in the second sentence came to be. It would be more difficult to draw a causal inference in an example like \"He hit his nail. So his father ran away\", although one could create an inference on this with some fantasy. Causal inferences create causal connections between text elements. These connections are separated into local connections and global connections. Local connections are made within a range of 1 to 3 sentences. This depends on factors like the capacity of the working memory and the concentration due reading. Global connections are drawn between the information in one sentence together with the background information gathered so far about the whole text. Problems can occur with Causal Inferences when a story is inconsistent. For example, vegans eating steak would be inconsistent. An interesting fact about Causal Inferences (Goldstein, 2005) is that the kind of Inferences we draw here that are not easily seen at first are easier to remember. This may be due to the fact that they required a higher mental processing capacity while drawing the inference. So this \"not-so-easy\" inference seems to be marked in a way that it is easier to remember it. ### Predictive / Forward Inference Predictive/Forward Inferences uses the General World Knowledge of the reader to build his prediction of the consequences of what is currently happening in the story into the Situation Model. ### Integrating Inferences into Situation Models The question how models enter inferential processes is highly controversial in the two disciplines of cognitive psychology and artificial intelligence. A.I. gave a deep insight in psychological procedures and since the two disciplines crossed their ways and give two main bases of the cognitive science. The arguments in these are largely independent from each other although they have much in common. Johnson-Laird (1983) makes a distinction between three types of reasoning-theories in which inferencing plays an important role. The first class gears to logical calculi and have been implemented in many formal system. The programming language Prolog arises from this way of dealing with reasoning and in psychology many theories postulate formal rules of inference, a \"mental logic.\" These rules work in a purely syntactic way and so are \"context free,\" blind for the context of its content. A simple example clarifies the problem with this type of theory: ` If patients have cystitis, then they are given penicillin.` and the logical conclusion: ` If patients have cystitis and are allergic to penicillin, then they are given penicillin` This is logically correct, but seems to fail our common sense of logic. The second class of theories postulate content specific rules of inference. Their origin lies in programming languages and production systems. They work with forms like \"If x is a, then x is b\". If one wants to show that x is b, showing that x is a sub-goal of this argumentation. The idea of basing psychological theories of reasoning on content specific rules was discussed by Johnson-Laird and Wason and various sorts of such theories have been proposed. A related idea is that reasoning depends on the accumulation of specific examples within a connectionist framework, where the distinction between inference and recall is blurred. The third class of theories is based on mental models and does not use any rules of inferencing. The process of building mental models of things heard or read. The models are in an permanent change of updates. A model built, will be equipped with new features of the new information as long as there is no information, which generates a conflict with that model. If this is the case the model is generally re-built, so that the conflict generating information fits into the new model. ## Important Topics of current research ### Linguistic Cues versus World Knowledge According to many researchers, language is the set of processing instructions on how to build up the Situation Model of the represented situation (Gernsbacher, 1990; Givon, 1992; Kintsch, 1992; Zwaan & Radvansky, 1998). As mentioned, readers use the lexical cues and information to connect the different situational dimensions and integrate them into the model. Another important point here is prior world knowledge. World knowledge also influences how the different information in a situation model are related. The relation between linguistic cues and world knowledge is therefore an important topic of current and future research in the area of Situation Models. ### Multidimensionality Another important aspect of current research in the area of Situation Models is the Multidimensionality of the Models. The main aspect is here how the different dimensions relate to each other, how they influence and interact. The question here is also if they interact at all and which interact. Most studies in the field were only about one or a few of the situational dimensions. ## References Ashwin Ram, et al. (1999) Understanding Language Understanding - chapter 5 Baggett, P. (1979). Structurally equivalent stories in movie and text and the effect of the medium on recall. Journal of Verbal Learning and Verbal Behavior, 18, 333-356. Bertram F. Malle, et al. (2001) Intentions and Intentionality - chapter 9 Boroditsky, L. (2000). Metaphoric Structuring: Understanding time through spatial metaphors. Cognition, 75, 1-28. Carlson-Radvansky, L. A., & Radvansky, G. A. (1996). The influence of functional relations on spatial term selection. Psychological Science, 7, 56-60. Carreiras, M., et al. (1996). The use of stereotypical gender information in constructing a mental model: Evidence from English and Spanish. Quarterly Journal of Experimental Psychology, 49A, 639-663. Dahan, D., & Tanenhaus, M.K. (2002). Activation of conceptual representations during spoken word recognition. Abstracts of the Psychonomic Society, 7, 14. Ericsson, K. A., & Kintsch, W. (1995). Long-term working memory. Psychological Review, 102, 211-245. Farah, M. J., & McClelland, J. L. (1991). A computational model of semantic memory impairment: modality specificity and emergent category specificity. Journal of Experimental Psychology: General, 210, 339-357. Fincher-Kiefer (2001). Perceptual components of situation models. Memory & Cognition, 29 , 336-343. Fincher-Kiefer, R., et al. (1988). On the role of prior knowledge and task demands in the processing of text. Journal of Memory and Language, 27, 416-428. Garrod, S. C., & Sanford, A. J. (1989). Discourse models as interfaces between language and the spatial world. Journal of Semantics, 6, 147-160. Gernsbacher, M.A. (1990), Language comprehension as structure building. Hillsdale, NJ: Erlbaum. Glenberg, A. M., & Kaschak, M. P. (2002). Grounding language in action. Psychonomic Bulletin & Review, 9, 558-565. Glenberg, A. M., et al. (1987) Mental models contribute to foregrounding during text comprehension. Journal of Memory and Language 26:69-83. Givon, T. (1992), The grammar of referential coherence as mental processing instructions, Linguistics, 30, 5-55. Goldman, S.R., et al. (1996). Extending capacityconstrained construction integration: Towards \"smarter\" and flexible models of text comprehension. Models of understanding text (pp. 73--113). Goldstein, E.Bruce, Cognitive Psychology, Connecting Mind, Research, and Everyday Experience (2005) - . Graesser, A. C., Singer, M., & Trabasso, T. (1994), Constructing inferences during narrative text comprehension. Psychological Review, 101, 371-395. Holland, John H. , et al. (1986) Induction. Horton, W.S., Rapp, D.N. (in press). Occlusion and the Accessibility of Information in Narrative Comprehension. Psychonomic Bulletin & Review. Isenberg, N., et al. (1999). Linguistic threat activates the human amygdala. Proceedings of the National Academy of Sciences, 96, 10456-10459. Johnson-Laird, P. N. (1983). Mental models: Towards a cognitive science of language, inference, and consciousness. Cambridge, MA: Harvard University Press. John R. Koza, et al. (1996) Genetic Programming Just, M. A., & Carpenter, P. A. (1992). A capacity hypothesis of comprehension: Individual differences ih working memory. Psychological Review, 99, 122-149. Kaup, B., & Zwaan, R.A. (in press). Effects of negation and situational presence on the accessibility of text information. Journal of Experimental Psychology: Learning, Memory, and Cognition. Keefe, D. E., & McDaniel, M. A. (1993). The time course and durability of predictive inferences. Journal of Memory and Language, 32, 446-463. Kintsch, W. (1988), The role of knowledge in discourse comprehension: A construction-integration model, Psychological Review, 95, 163-182. Kintsch, W., & van Dijk, T. A. (1978), Toward a model of text comprehension and production, Psychological Review, 85, 363-394. Kintsch, W. (1992), How readers construct situation models for stories: The role of syntactic cues and causal inferences. In A. E Healy, S. M. Kosslyn, & R. M. Shiffrin (Eds.), From learning processes to cognitive processes. Essays in honor of William K. Estes (Vol. 2, pp. 261 -- 278). Klatzky, R.L., et al. (1989). Can you squeeze a tomato? The role of motor representations in semantic sensibility judgments. Journal of Memory and Language, 28, 56-77. Martin, A., & Chao, L. L. (2001). Semantic memory and the brain: structure and processes. Current Opinion in Neurobiology, 11, 194-201. McRae, K., et al. (1997). On the nature and scope of featural representations of word meaning. Journal of Experimental Psychology: General, 126, 99-130. Mehler, Jacques, & Franck, Susana. (1995) Cognition on Cognition - chapter 9 Miceli, G., et al. (2001). The dissociation of color from form and function knowledge. Nature Neuroscience, 4, 662-667. Morrow, D., et al. (1987). Accessibility and situation models in narrative comprehension. Journal of Memory and Language, 26, 165-187. Pulvermüller, F. (1999). Words in the brain\'s language. Behavioral and Brain Sciences, 22, 253-270. Pulvermüller, F. (2002). A brain perspective on language mechanisms: from discrete neuronal ensembles to serial order. Progress in Neurobiology, 67, 85--111. Radvansky, G. A., & Zwaan, R.A. (1998). Situation models. Schmalhofer, F., MacDaniel, D. Keefe (2002). A Unified Model for Predictive and Bridging Inferences Schneider, W., & Körkel, J. (1989). The knowledge base and text recall: Evidence from a short-term longitudinal study. Contemporary Educational Psychology, 14, 382-393. Singer, M., et al. (1992). Validation of causal bridging inferences. Journal of Memory and Language, 31, 507-524. Spivey, M.J., et al. (2000). Eye movements during comprehension of spoken scene descriptions. Proceedings of the Twenty-second Annual Meeting of the Cognitive Science Society (pp. 487--492). Stanfield, R.A. & Zwaan, R.A. (2001). The effect of implied orientation derived from verbal context on picture recognition. Psychological Science, 12, 153-156. Talmy, Leonard,(2000) Toward a Cognitive Semantics - Vol. 1 - chapter1 van den Broek, P., et al. (1996). A \"landscape\" view of reading: Fluctuating patterns of activation and the construction of a memory representation. In B. K. Britton & A. C. Graesser (Eds.), Models of understanding text (pp. 165--187). Van Dijk, T. A., and W. Kintsch. (1983).Strategies of discourse comprehension. Yekovich, F.R., et al. (1990). The influence of domain knowledge on inferencing in low-aptitude individuals. In A. C. Graesser & G. H. Bower (Eds.), The psychology of learning and motivation (Vol. 25, pp. 175--196). New York: Academic Press. Zwaan, R.A. (1996). Processing narrative time shifts. Journal of Experimental Psychology: Learning, Memory and Cognition, 22, 1196-1207 Zwaan, R.A. (2003), The Immersed Experiencer: Toward an embodied theory of language comprehension.B.H. Ross (Ed.) The Psychology of Learning and Motivation, Vol. 44. New York: Academic Press. Zwaan, R. A., et al. (1998). Situation-model construction during translation. Manuscript in preparation, Florida State University. Zwaan, R. A., et al. ( 1995 ). The construction of situation models in narrative comprehension: An event-indexing model. Psychological Science, 6, 292-297. Zwaan, R. A., et al. (1995). Dimensions of situation model construction in narrative comprehension. Journal of Experimental Psychology.\" Learning, Memory, and Cognition, 21, 386-397. Zwaan, R. A., Radvansky (1998), Situation Models in Language Comprehension and Memory. in Psychological Bulletin, Vol.123,No2 p. 162-185. Zwaan, R.A., et al. (2002). Do language comprehenders routinely represent the shapes of objects? Psychological Science, 13, 168-171. Zwaan, R.A., & Yaxley, R.H. (a). Spatial iconicity affects semantic-relatedness judgments. Psychonomic Bulletin & Review. Zwaan, R.A., & Yaxley, R.H. (b). Hemispheric differences in semantic-relatedness judgments. Cognition. ## Links Cognitive Psychology Osnabrück Summer School course on Situation Models and Embodied Language Processes Dr. Rolf A. Zwaan\'s Homepage with many Papers International Hanse-Conference on Higher level language processes in the brain: Inference and Comprehension Processes 2003 University of Notre Dame Situation Model Research Group
# Cognitive Psychology and Cognitive Neuroscience/Reasoning and Decision Making No matter which public topic you discuss or which personal aspect you worry about -- you need reasons for your opinion and argumentation. Moreover, the ability of reasoning is responsible for your cognitive features of decision making and choosing among alternatives. Everyone of us uses these two abilities in everyday life to the utmost. Let us, therefore, consider the following scene of Knut\'s life: "It is again a rainy afternoon in Osnabrück (Germany) and as Knut and his wife are tired of observing the black crows in their garden they decide to escape from the shabby weather and spend their holidays in Spain. Knut has never been to Spain before and is pretty excited. They will leave the next day, thus he is packing his bag. The crucial things first: some underwear, some socks, a pair of pyjamas and his wash bag with a toothbrush, shampoo, soap, sun milk and insect spray. But, Knut cannot find the insect spray until his wife tells him that she lost it and will buy some new. He advises her to take an umbrella for the way to the chemist as it is raining outside, before he turns back to his packing task. But what did he already pack into his bag? Immediately, he remembers and continues, packing his clothing into the bag, considering that each piece fits another one and finally his Ipod as he exclusively listens to music with this device. Since the two of them are going on summer holidays, Knut packs especially shorts and T-Shirts into his bag. After approximately half an hour, he is finally convinced that he has done everything necessary for having some fine holidays." With regard to this sketch of Knut\'s holiday preparation, we will explain the basic principles of reasoning and decision making. In the following, it will be shown how much cognitive work is necessary for this fragment of everyday life. After presenting an insight into the topic, we will illustrate what kind of brain lesions lead to what kind of impairments of these two cognitive features. ## Reasoning In a process of reasoning available information is taken into account in form of premises "wikilink"). Through a process of inferencing a conclusion is reached on the base of these premises. The conclusion's content of information goes beyond the one of the premises. To make this clear consider the following consideration Knut makes before planning his holiday: ` ``1. Premise: In all countries in southern Europe it is pretty warm during summer.`\ ` ``2. Premise: Spain is in southern Europe.`\ ` ``Conclusion: Therefore, in Spain it is pretty warm during summer.` The conclusion in this example follows directly from the premises but it entails information which is not explicitly stated in the premises. This is a rather typical feature of a process of reasoning. In the following it is decided between the two major kinds of reasoning, namely inductive and deductive which are often seen as the complement of one another. ### Deductive reasoning Deductive reasoning is concerned with syllogisms in which the conclusion follows logically from the premises. The following example about Knut makes this process clear: ` ``1.Premise: Knut knows: If it is warm, one needs shorts and T-Shirts.`\ ` ``2.Premise: He also knows that it is warm in Spain during summer.`\ ` ``Conclusion: Therefore, Knut reasons that he needs shorts and T-Shirts in Spain.` In the given example it is obvious that the premises are about rather general information and the resulting conclusion is about a more special case which can be inferred from the two premises. Hereafter it is differentiated between the two major kinds of syllogisms, namely categorical and conditional ones. #### Categorical syllogisms In categorical syllogisms the statements of the premises begin typically with "all", "none" or "some" and the conclusion starts with "therefore" or "hence". These kinds of syllogisms fulfill the task of describing a relationship between two categories. In the example given above in the introduction of deductive reasoning these categories are Spain and the need for shorts and T-Shirts. Two different approaches serve the study of categorical syllogisms which are the normative approach and the descriptive approach. ##### The normative approach The normative approach is based on logic and deals with the problem of categorizing conclusions as either valid or invalid. "Valid" means that the conclusion follows logically from the premises whereas "invalid" means the contrary. Two basic principles and a method called Euler Circles (Figure 1) have been developed to help judging about the validity. The first principle was created by Aristotle and says "If the two premises are true, the conclusion of a valid syllogism must be true" (cp. Goldstein, 2005). The second principle describes that "The validity of a syllogism is determined only by its form, not its content." These two principles explain why the following syllogism is (surprisingly) valid: ` ``All flowers are animals. All animals can jump. Therefore, all flowers can jump.` Even though it is quite obvious that the first premise is not true and further that the conclusion is not true, the whole syllogism is still valid. Applying formal logic to the syllogism in the example, the conclusion is valid. ![](eulercircles.jpg "eulercircles.jpg"){width="500"} Figure 1, Euler Circles Due to this precondition it is possible to display a syllogism formally with symbols or letters and explain its relationship graphically with the help of diagrams. There are various ways to demonstrate a premise graphically. Starting with a circle to represent the first premise and adding one or more circles for the second one (Figure 1), the crucial move is to compare the constructed diagrams with the conclusion. It should be clearly laid out whether the diagrams are contradictory or not. Agreeing with one another, the syllogism is valid. The displayed syllogism (Figure 1) is obviously valid. The conclusion shows that everything that can jump contains animals which again contains flowers. This agrees with the two premises which point out that flowers are animals and that these are able to jump. The method of Euler Circles is a good device to make syllogisms better conceivable. ##### The descriptive approach The descriptive approach is concerned with estimating people´s ability of judging validity and explaining judging errors. This psychological approach uses two methods in order to determine people\`s performance: `Method of evaluation``: People are given two premises, a conclusion and the task to judge whether the syllogism is valid or not.`\ ` (preferred one)`\ `Method of production``: Participants are supplied with two premises and asked to develop a logically valid conclusion.`\ ` (if possible)` While using the method of evaluation researchers found typical misjudgments about syllogisms. Premises starting with "All", "Some" or "No" imply a special atmosphere and influence a person in the process of decision making. One mistake often occurring is judging a syllogism incorrectly as valid, in which the two premises as well as the conclusion starts with "All". The influence of the provided atmosphere leads to the right decision at most times, but is definitely not reliable and guides the person to a rash decision. This phenomenon is called the atmosphere effect. In addition to the form of a syllogism, the content is likely to influence a person's decision as well and causes the person to neglect his logical thinking. The belief bias states that people tend to judge syllogisms with believable conclusions as valid, while they tend to judge syllogisms with unbelievable conclusions as invalid. Given a conclusion as like "Some bananas are pink", hardly any participants would judge the syllogism as valid, even though it might be valid according to its premises (e.g. Some bananas are fruits. All fruits are pink.) ##### Mental models of deductive reasoning It is still not possible to consider what mental processes might occur when people are trying to determine whether a syllogism is valid. After researchers observed that Euler Circles can be used to determine the validity of a syllogism, Phillip Johnson--Laird (1999) wondered whether people would use such circles naturally without any instruction how to use them. At the same time he found out that they do not work for some more complex syllogisms and that a problem can be solved by applying logical rules, but most people solve them by imagining the situation. This is the basic idea of people using mental models -- a specific situation that is represented in a person's mind that can be used to help determine the validity of syllogisms -- to solve deductive reasoning problems. The basic principle behind the Mental Model Theory is: A conclusion is valid only if it cannot be refuted by any mode of the premises. This theory is rather popular because it makes predictions that can be tested and because it can be applied without any knowledge about rules of logic. But there are still problems facing researchers when trying to determine how people reason about syllogisms. These problems include the fact that a variety of different strategies are used by people in reasoning and that some people are better in solving syllogisms than others. ##### Effects of culture on deductive reasoning People can be influenced by the content of syllogisms rather than by focusing on logic when judging their validity. Psychologists have wondered whether people are influenced by their cultures when judging. Therefore they have done cross--cultural experiments in which reasoning problems were presented to people of different cultures. They observed that people from different cultures judge differently to these problems. People use evidence from their own experience (empirical evidence) and ignore evidence presented in the syllogism (theoretical evidence). #### Conditional syllogisms Another type of syllogisms is called "conditional syllogism". Just like the categorical one, it also has two premises and a conclusion. In difference the first premise has the form "If ... then". Syllogisms like this one are common in everyday life. Consider the following example from the story about Knut: ` ``` 1. Premise: If it is raining, Knut`s wife gets wet. ``\ ` ``2. Premise: It is raining.`\ ` ``` Conclusion: Therefore, Knut`s wife gets wet. `` Conditional syllogisms are typically given in the abstract form: "If p then q", where "p" is called the antecedent and "q" the consequent. ##### Forms of conditional syllogisms There are four major forms of conditional syllogisms, namely Modus Ponens, Modus Tollens, Denying The Antecedent and Affirming The Consequent. These are illustrated in the table below (Figure 2) by means of the conditional syllogism above (i.e. If it is raining, Knut\`s wife gets wet). The table indicates the premises, the resulting conclusions and it shows whether these are valid or not. The lowermost row displays the relative number of correct judgements people make about the validity of the conclusions. +-------------+-------------+-------------+-------------+-------------+ \| \| Modus \| Modus \| Denying the \| Affirming \| \| \| Ponens \| Tollens \| Antecedent \| the \| \| \| \| \| \| Consequent \| +-------------+-------------+-------------+-------------+-------------+ \| Description \| The \| The \| The \| The \| \| \| antecedent \| consequent \| antecedent \| antecedent \| \| \| of the \| of the \| of the \| of the \| \| \| first \| first \| first \| first \| \| \| premise is \| premise is \| premise is \| premise is \| \| \| affirmed in \| negated in \| negated in \| affirmed in \| \| \| the second \| the second \| the second \| the second \| \| \| premise. \| premise. \| premise. \| premise. \| +-------------+-------------+-------------+-------------+-------------+ \| Formal \| If P then \| If P then \| If P then \| If P then \| \| \| Q. P\ \| Q. Not-Q\ \| Q. Not-P\ \| Q. Q\ \| \| \| Therefore \| Therefore \| Therefore \| Therefore \| \| \| Q. \| Not-P. \| Not-Q. \| P. \| +-------------+-------------+-------------+-------------+-------------+ \| Example \| If it is \| If it is \| If it is \| If it is \| \| \| raining, \| raining, \| raining, \| raining, \| \| \| Knut\'s \| Knut\'s \| Knut\'s \| Knut\'s \| \| \| wife gets \| wife gets \| wife gets \| wife gets \| \| \| wet. It is \| wet. \| wet. It is \| wet. \| \| \| raining.\ \| Knut\'s \| not \| Knut\'s \| \| \| Therefore \| wife does \| raining.\ \| wife gets \| \| \| Knut\'s \| not get \| Therefore \| wet\ \| \| \| wife gets \| wet.\ \| Knut\'s \| Therefore \| \| \| wet \| Therefore \| wife does \| it is \| \| \| \| it is not \| not get \| raining. \| \| \| \| raining. \| wet. \| \| +-------------+-------------+-------------+-------------+-------------+ \| Validity \| ! \| ! \| ![{ \| mark.svg"){ \| \| \| heck.svg"){ \| heck.svg"){ \| width="14"} \| width="14"} \| \| \| width="14"} \| width="14"} \| INVALID \| INVALID \| \| \| VALID \| VALID \| \| \| +-------------+-------------+-------------+-------------+-------------+ \| Correct \| 97% \| 60% \| 40% \| 40% \| \| Judgements \| correctly \| correctly \| correctly \| correctly \| \| \| identify as \| identify as \| identify as \| identify as \| \| \| valid. \| valid. \| invalid. \| invalid. \| +-------------+-------------+-------------+-------------+-------------+ : Figure 2, Different kinds of conditional syllogisms Obviously, the validity of the syllogisms with valid conclusions is easier to judge in a correct manner than the validity of the ones with invalid conclusions. The conclusion in the instance of the modus ponens is apparently valid. In the example it is very clear that Knut\`s wife gets wet, if it is raining. The validity of the modus tollens is more difficult to recognize. Referring to the example, in the case that Knut\`s wife does not get wet it can\`t be raining. Because the first premise says that if it is raining, she gets wet. So the reason for Knut\`s wife not getting wet is that it is not raining. Consequently, the conclusion is valid. The validity of the remaining two kinds of conditional syllogisms is judged correctly only by 40% of people. If the method of denying the antecedent is applied, the second premise says that it is not raining. But from this fact it follows not logically that Knut\`s wife does not get wet -- obviously rain is not the only reason for her to get wet. It could also be the case that the sun is shining and Knut tests his new water pistol and makes her wet. So, this kind of conditional syllogism does not lead to a valid conclusion. Affirming the consequent in the case of the given example means that the second premise says that Knut\`s wife gets wet. But again the reason for this can be circumstances apart from rain. So, it follows not logically that it is raining. In consequence, the conclusion of this syllogism is invalid. The four kinds of syllogisms have shown that it is not always easy to make correct judgments concerning the validity of the conclusions. The following passages will deal with other errors people make during the process of conditional reasoning. ##### The Wason Selection Task The Wason Selection Task is a famous experiment which shows that people make more errors in the process of reasoning, if it is concerned with abstract items than if it involves real-world items (Wason, 1966). In the abstract version of the Wason Selection Task four cards are shown to the participants with each a letter on one side and a number on the other (Figure 3, yellow cards). The task is to indicate the minimum number of cards that have to be turned over to test whether the following rule is observed: "If there is a vowel on one side then there is an even number on the other side". 53% of participants selected the 'E' card which is correct, because turning this card over is necessary for testing the truth of the rule. However still another card needs to be turned over. 64% indicated that the '4' card has to be turned over which is not right. Only 4% of participants answered correctly that the '7' card needs to be turned over in addition to the 'E'. The correctness of turning over these two cards becomes more obvious if the same task is stated in terms of real-world items instead of vowels and numbers. One of the experiments for determining this was the beer/drinking-age problem used by Richard Griggs and James Cox (1982). This experiment is identical to the Wason Selection Task except that instead of numbers and letters on the cards everyday terms (beer, soda and ages) were used (Figure 3, green cards). Griggs and Cox gave the following rule to the participants: "If a person is drinking beer then he or she must be older than 19 years." In this case 73% of participants answered in a correct way, namely that the cards with "Beer" and "14 years" on it have to be turned over to test whether the rule is kept. !Figure 3, The Wason Selection Task{width="400"} Why is the performance better in the case of real--world items? There are two different approaches which explain why participants' performance is significantly better in the case of the beer/drinking-age problem than in the abstract version of the Wason Selection Task, namely one approach concerning permission schemas and an evolutionary approach. The regulation: "If one is 19 years or older then he/she is allowed to drink alcohol", is known by everyone as an experience from everyday life (also called permission schema). As this permission schema is already learned by the participants it can be applied to the Wason Selection Task for real--world items to improve participants\` performance. On the contrary such a permission schema from everyday life does not exist for the abstract version of the Wason Selection Task. The evolutionary approach concerns the important human ability of cheater-detection . This approach states that an important aspect of human behaviour especially in the past was/is the ability for two persons to cooperate in a way that is beneficial for both of them. As long as each person receives a benefit for whatever he/she does in favour of the other one, everything works well in their social exchange. But if someone cheats and receives benefit from others without giving it back, some problem arises (see also chapter Cognitive Psychology and Cognitive Neuroscience/Evolutionary Perspective on Social Cognitions#3. Evolutionary Perspective on Social Cognitions). It is assumed that the property to detect cheaters has become a part of human\`s cognitive makeup during evolution. This cognitive ability improves the performance in the beer/drinking-age version of the Wason Selection Task as it allows people to detect a cheating person who does not behave according to the rule. Cheater-detection does not work in the case of the abstract version of the Wason Selection Task as vowels and numbers do not behave or even cheat at all as opposed to human beings. ### Inductive reasoning In the previous sections deductive reasoning was discussed, reaching conclusions based on logical rules applied to a set of premises. However, many problems cannot be represented in a way that would make it possible to use these rules to get a conclusion. This subchapter is about a way to be able to decide in terms of these problems as well: inductive reasoning. !Figure 4, Deductive and inductive reasoning{width="300"} Inductive reasoning is the process of making simple observations of a certain kind and applying these observations via generalization to a different problem to make a decision. Hence one infers from a special case to the general principle which is just the opposite of the procedure of deductive reasoning (Figure 4). A good example for inductive reasoning is the following: ` ``Premise: All crows Knut and his wife have ever seen are black.`\ ` ``Conclusion: Therefore, they reason that all crows on earth are black.` In this example it is obvious that Knut and his wife infer from the simple observation about the crows they have seen to the general principle about all crows. Considering figure 5 this means that they infer from the subset (yellow circle) to the whole (blue circle). As in this example it is typical in a process of inductive reasoning that the premises are believed to support the conclusion, but do not ensure it. ![{width="300"} Figure 5 #### Forms of inductive reasoning The two different forms of inductive reasoning are \"strong\" and \"weak\" induction. The former describes that the truth of the conclusion is very likely, if the assumed premises are true. An example for this form of reasoning is the one given in the previous section. In this case it is obvious that the premise (\"All crows Knut and his wife have ever seen are black\") gives good evidence for the conclusion (\"All crows on earth are black\") to be true. But nevertheless it is still possible, although very unlikely, that not all crows are black. On the contrary, conclusions reached by \"weak induction\" are supported by the premises in a rather weak manner. In this approach the truth of the premises makes the truth of the conclusion possible, but not likely. An example for this kind of reasoning is the following: ` ``Premise: Knut always hears music with his IPod.`\ ` ``Conclusion: Therefore, he reasons that all music is only heard with IPods.` In this instance the conclusion is obviously false. The information the premise contains is not very representative and although it is true, it does not give decisive evidence for the truth of the conclusion. To sum it up, strong inductive reasoning gets to conclusions which are very probable whereas the conclusions reached through weak inductive reasoning on the base of the premises are unlikely to be true. #### Reliability of conclusions If the strength of the conclusion of an inductive argument has to be determined, three factors concerning the premises play a decisive role. The following example which refers to Knut and his wife and the observations they made about the crows (see previous sections) displays these factors: When Knut and his wife observe in addition to the black crows in Germany also the crows in Spain, the number of observations they make concerning the crows obviously increases. Furthermore, the representativeness of these observations is supported, if Knut and his wife observe the crows at all different day- and nighttimes and see that they are black every time. Theoretically it may be that the crows change their colour at night what would make the conclusion that all crows are black wrong. The quality of the evidence for all crows to be black increases, if Knut and his wife add scientific measurements which support the conclusion. For example they could find out that the crows\' genes determine that the only colour they can have is black. Conclusions reached through a process of inductive reasoning are never definitely true as no one has seen all crows on earth and as it is possible, although very unlikely, that there is a green or brown exemplar. The three mentioned factors contribute decisively to the strength of an inductive argument. So, the stronger these factors are, the more reliable are the conclusions reached through induction. #### Processes and constraints In a process of inductive reasoning people often make use of certain heuristics which lead in many cases quickly to adequate conclusions but sometimes may cause errors. In the following, two of these heuristics (availability heuristic and representativeness heuristic) are explained. Subsequently, the confirmation bias is introduced which sometimes influences people\'s reasons according to their own opinion without them realising it. The availability heuristic Things that are more easily remembered are judged to be more prevalent. An example for this is an experiment done by Lichtenstein et al. (1978). The participants were asked to choose from two different lists the causes of death which occur more often. Because of the availability heuristic people judged more "spectacular" causes like homicide or tornado to cause more deaths than others, like asthma. The reason for the subjects answering in such a way is that for example films and news in television are very often about spectacular and interesting causes of death. This is why these information are much more available to the subjects in the experiment. Another effect of the usage of the availability heuristic is called illusory correlations. People tend to judge according to stereotypes. It seems to them that there are correlations between certain events which in reality do not exist. This is what is known by the term "prejudice". It means that a much oversimplified generalization about a group of people is made. Usually a correlation seems to exist between negative features and a certain class of people (often fringe groups). If, for example, one\'s neighbour is jobless and very lazy one tends to correlate these two attributes and to create the prejudice that all jobless people are lazy. This illusory correlation occurs because one takes into account information which is available and judges this to be prevalent in many cases. The representativeness heuristic If people have to judge the probability of an event they try to find a comparable event and assume that the two events have a similar probability. Amos Tversky and Daniel Kahneman (1974) presented the following task to their participants in an experiment: "We randomly chose a man from the population of the U.S., Robert, who wears glasses, speaks quietly and reads a lot. Is it more likely that he is a librarian or a farmer?" More of the participants answered that Robert is a librarian which is an effect of the representativeness heuristic. The comparable event which the participants chose was the one of a typical librarian as Robert with his attributes of speaking quietly and wearing glasses resembles this event more than the event of a typical farmer. So, the event of a typical librarian is better comparable with Robert than the event of a typical farmer. Of course this effect may lead to errors as Robert is randomly chosen from the population and as it is perfectly possible that he is a farmer although he speaks quietly and wears glasses. !Figure 6, Feminist bank tellers{width="500"} The representativeness heuristic also leads to errors in reasoning in cases where the conjunction rule is violated. This rule states that the conjunction of two events is never more likely to be the case than the single events alone. An example for this is the case of the feminist bank teller (Tversky & Kahneman, 1983). If we are introduced to a woman of whom we know that she is very interested in women's rights and has participated in many political activities in college and we are to decide whether it is more likely that she is a bank teller or a feminist bank teller, we are drawn to conclude the latter as the facts we have learnt about her resemble the event of a feminist bank teller more than the event of only being a bank teller. But it is in fact much more likely that somebody is just a bank teller than it is that someone is a feminist in addition to being a bank teller. This effect is illustrated in figure 6 where the green square, which stands for just being a bank teller, is much larger and thus more probable than the smaller violet square, which displays the conjunction of bank tellers and feminists, which is a subset of bank tellers. Confirmation bias This phenomenon describes the fact that people tend to decide in terms of what they themselves believe to be true or good. If, for example, someone believes that one has bad luck on Friday the thirteenth, he will especially look for every negative happening at this particular date but will be inattentive to negative happenings on other days. This behaviour strengthens the belief that there exists a relationship between Friday the thirteenth and having bad luck. This example shows that the actual information is not taken into account to come to a conclusion but only the information which supports one\'s own belief. This effect leads to errors as people tend to reason in a subjective manner, if personal interests and beliefs are involved. All the mentioned factors influence the subjective probability of an event so that it differs from the actual probability (probability heuristic). Of course all of these factors do not always appear alone, but they influence one another and can occur in combination during the process of reasoning. #### Why inductive reasoning at all? All the described constraints show how prone to errors inductive reasoning is and so the question arises, why we use it at all? But inductive reasons are important nevertheless because they act as shortcuts for our reasoning. It is much easier and faster to apply the availability heuristic or the representativeness heuristic to a problem than to take into account all information concerning the current topic and draw a conclusion by using logical rules. In the following excerpt of very usual actions there is a lot of inductive reasoning involved although one does not realize it on the first view. It points out the importance of this cognitive ability: The sunrise every morning and the sunset in the evening, the change of seasons, the TV program, the fact that a chair does not collapse when we sit on it or the light bulb that flashes after we have pushed a button. All of these cases are conclusions derived from processes of inductive reasoning. Accordingly, one assumes that the chair one is sitting on does not collapse as the chairs on which one sat before did not collapse. This does not ensure that the chair does not break into pieces but nevertheless it is a rather helpful conclusion to assume that the chair remains stable as this is very probable. To sum it up, inductive reasoning is rather advantageous in situations where deductive reasoning is just not applicable because only evidence but no proved facts are available. As these situations occur rather often in everyday life, living without the use of inductive reasoning is inconceivable. Induction vs. deduction The table below (Figure 7) summarises the most prevalent properties and differences between deductive and inductive reasoning which are important to keep in mind. ------------ --------------------------------------------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------- Deductive Reasoning Inductive Reasoning Premises Stated as facts or general principles (\"It is warm in the Summer in Spain.\") Based on observations of specific cases (\"All crows Knut and his wife have seen are black.\") Conclusion Conclusion is more special than the information the premises provide. It is reached directly by applying logical rules to the premises. Conclusion is more general than the information the premises provide. It is reached by generalizing the premises\' information. Validity If the premises are true, the conclusion must be true. If the premises are true, the conclusion is probably true. Usage More difficult to use (mainly in logical problems). One needs facts which are definitely true. Used often in everyday life (fast and easy). Evidence is used instead of proved facts. ------------ --------------------------------------------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------- : Figure 7, Induction vs. deduction ## Decision making According to the different levels of consequences, each process of making a decision requires appropriate effort and various aspects to be considered. The following excerpt from the story about Knut makes this obvious: "After considering facts like the warm weather in Spain and shirts and shorts being much more comfortable in this case (information gathering and likelihood estimation) Knut reasons that he needs them for his vacation. In consequence, he finally makes the decision to pack mainly shirts and shorts in his bag (final act of choosing)." Now it seems like there cannot be any decision making without previous reasoning, but that is not true. Of course there are situations in which someone decides to do something spontaneously, with no time to reason about it. We will not go into detail here but you might think about questions like \"Why do we choose one or another option in that case?\" ### Choosing among alternatives The psychological process of decision making constantly goes along with situations in daily life. Thinking about Knut again we can imagine him to decide between packing more blue or more green shirts for his vacation (which would only have minor consequences) but also about applying a specific job or having children with his wife (which would have relevant influence on important circumstances of his future life). The mentioned examples are both characterized by personal decisions, whereas professional decisions, dealing for example with economic or political issues, are just as important. #### The utility approach !Figure 8, Relation between (monetary) gains/losses and their subjective value according to Prospect Theory gains/losses and their subjective value according to Prospect Theory") There are three different ways to analyze decision making. The normative approach assumes a rational decision-maker with well-defined preferences. While the rational choice theory is based on a priori considerations, the descriptive approach is based on empirical observations and on experimental studies of choice behavior. The prescriptive enterprise develops methods in order to improve decision making. According to Manktelow and Reber´s definition, "utility refers to outcomes that are desirable because they are in the person's best interest" (Reber, A. S., 1995; Manktelow, K., 1999). This normative/descriptive approach characterizes optimal decision making by the maximum expected utility in terms of monetary value. This approach can be helpful in gambling theories, but simultaneously includes several disadvantages. People do not necessarily focus on the monetary payoff, since they find value in things other than money, such as fun, free time, family, health and others. But that is not a big problem, because it is possible to apply the graph (Figure 8), which shows the relation between (monetary) gains/losses and their subjective value / utility, which is equal to all the valuable things mentioned above. Therefore, not choosing the maximal monetary value does not automatically describe an irrational decision process. #### Misleading effects But even respecting the considerations above there might still be problems to make the "right" decision because of different misleading effects, which mainly arise because of the constraints of inductive reasoning. In general this means that our model of a situation/problem might not be ideal to solve it in an optimal way. The following three points are typical examples for such effects. Subjective models This effect is rather equal to the illusory correlations mentioned before in the part about the constraints of inductive reasoning. It is about the problem that models which people create might be misleading, since they rely on subjective speculations. An example could be deciding where to move by considering typical prejudices of the countries (e.g. always good pizza, nice weather and a relaxed life-style in Italy in contrast to some kind of boring food and steady rain in Great Britain). The predicted events are not equal to the events occurring indeed. (Kahneman & Tversky, 1982; Dunning & Parpal, 1989) Focusing illusion Another misleading effect is the so-called focusing illusion. By considering only the most obvious aspects in order to make a certain decision (e.g. the weather) people often neglect various really important outcomes (e.g. circumstances at work). This effect occurs more often, if people judge about others compared with judgments about their own living. Framing effect A problem can be described in different ways and therefore evoke different decision strategies. If a problem is specified in terms of gains, people tend to use a risk-aversion strategy, while a problem description in terms of losses leads to apply a risk-taking strategy. An example of the same problem and predictably different choices is the following experiment: A group of people is asked to imagine themselves \$300 richer than they are, is confronted with the choice of a sure gain of \$100 or an equal chance to gain \$200 or nothing. Most people avoid the risk and take the sure gain, which means they take the risk-aversion strategy. Alternatively if people are asked to assume themselves to be \$500 richer than in reality, given the options of a sure loss of \$100 or an equal chance to lose \$200 or nothing, the majority opts for the risk of losing \$200 by taking the risk seeking or risk-taking strategy. This phenomenon is known as framing effect and can also be illustrated by figure 8 above, which is a concave function for gains and a convex one for losses. (Foundations of Cognitive Psychology, Levitin, D. J., 2002) #### Justification in decision making Decision making often includes the need to assign a reason for the decision and therefore justify it. This factor is illustrated by an experiment by A. Tversky and E. Shafir (1992): A very attractive vacation package has been offered to a group of students who have just passed an exam and to another group of students who have just failed the exam and have the chance to rewrite it after the holidays coming up. All students have the options to buy the ticket straight away, to stay at home, or to pay \$5 for keeping the option open to buy it later. At this point, there is no difference between the two groups, since the number of students who passed the exam and decided to book the flight (with the justification of a deserving a reward), is the same as the number of students who failed and booked the flight (justified as consolation and having time for reoccupation). A third group of students who were informed to receive their results in two more days was confronted with the same problem. The majority decided to pay \$5 and keep the option open until they would get their results. The conclusion now is that even though the actual exam result does not influence the decision, it is required in order to provide a rationale. ### Executive functions !Figure 9, Left frontal lobe{width="350"} Subsequently, the question arises how this cognitive ability of making decisions is realized in the human brain. As we already know that there are a couple of different tasks involved in the whole process, there has to be something that coordinates and controls those brain activities -- namely the executive functions. They are the brain\'s conductor, instructing other brain regions to perform, or be silenced, and generally coordinating their synchronized activity (Goldberg, 2001). Thus, they are responsible for optimizing the performance of all "multi-threaded" cognitive tasks. Locating those executive functions is rather difficult, as they cannot be appointed to a single brain region. Traditionally, they have been equated with the frontal lobes, or rather the prefrontal regions of the frontal lobes; but it is still an open question whether all of their aspects can be associated with these regions. Nevertheless, we will concentrate on the prefrontal regions of the frontal lobes, to get an impression of the important role of the executive functions within cognition. Moreover, it is possible to subdivide these regions into functional parts. But it is to be noted that not all researchers regard the prefrontal cortex as containing functionally different regions. #### Executive functions in practice According to Norman and Shallice, there are five types of situations in which executive functions may be needed in order to optimize performance, as the automatic activation of behaviour would be insufficient. These are situations involving\... 1. \...planning or decision making. 2. \...error correction or trouble shooting. 3. \...responses containing novel sequences of actions. 4. \...technical difficulties or dangerous circumstances. 5. \...the control of action or the overcoming of strong habitual responses. The following parts will have a closer look to each of these points, mainly referring to brain-damaged individuals. Surprisingly, intelligence in general is not affected in cases of frontal lobe injuries (Warrington, James & Maciejewski, 1986). However, dividing intelligence into crystallised intelligence (based on previously acquired knowledge) and fluid intelligence (meant to rely on the current ability of solving problems), emphasizes the executive power of the frontal lobes, as patients with lesions in these regions performed significantly worse in tests of fluid intelligence (Duncan, Burgess & Emslie, 1995). 1. _Planning or decision making_ Impairments in abstract and conceptual thinking To solve many tasks it is important that one is able to use given information. In many cases, this means that material has to be processed in an abstract rather than in a concrete manner. Patients with executive dysfunction have abstraction difficulties. This is proven by a card sorting experiment (Delis et al., 1992): The cards show names of animals and black or white triangles placed above or below the word. Again, the cards can be sorted with attention to different attributes of the animals (living on land or in water, domestic or dangerous, large or small) or the triangles (black or white, above or below word). People with frontal lobe damage fail to solve the task because they cannot even conceptualize the properties of the animals or the triangles, thus are not able to deduce a sorting-rule for the cards (in contrast, there are some individuals only perseverating; they find a sorting-criterion, but are unable to switch to a new one). These problems might be due to a general difficulty in strategy formation. Goal directed behavior Let us again take Knut into account to get an insight into the field of goal directed behaviour -- in principle, this is nothing but problem solving since it is about organizing behavior towards a goal. Thus, when Knut is packing his bag for his holiday, he obviously has a goal in mind (in other words: He wants to solve a problem) -- namely get ready before the plane starts. There are several steps necessary during the process of reaching a certain goal: _Goal must be kept in mind_ Knut should never forget that he has to pack his bag in time. _Dividing into subtasks and sequencing_ Knut packs his bag in a structured way. He starts packing the crucial things and then goes on with rest. _Completed portions must be kept in mind_ If Knut already packed enough underwear into his bag, he would not need to search for more. _Flexibility and adaptability_ Imagine that Knut wants to pack his favourite T-Shirt, but he realizes that it is dirty. In this case, Knut has to adapt to this situation and has to pick another T-Shirt that was not in his plan originally. _Evaluation of actions_ Along the way of reaching his ultimate goal Knut constantly has to evaluate his performance in terms of 'How am I doing considering that I have the goal of packing my bag?'. Executive dysfunction and goal directed behavior The breakdown of executive functions impairs goal directed behavior to a large extend. In which way cannot be stated in general, it depends on the specific brain regions that are damaged. So it is quite possible that an individual with a particular lesion has problems with two or three of the five points described above and performs within average regions when the other abilities are tested. However, if only one link is missing from the chain, the whole plan might get very hard or even impossible to master. Furthermore, the particular hemisphere affected plays a role as well. Another interesting result was the fact that lesions in the frontal lobes of left and right hemisphere impaired different abilities. While a lesion in the right hemisphere caused trouble in making recency judgements, a lesion in the left hemisphere impaired the patient's performance only when the presented material was verbal or in a variation of the experiment that required self-ordered sequencing. Because of that we know that the ability to sequence behaviour is not only located in the frontal lobe but in the left hemisphere particularly when it comes to motor action. Problems in sequencing In an experiment by Milner (1982), people were shown a sequence of cards with pictures. The experiment included two different tasks: recognition trials and recency trials. In the former the patients were shown two different pictures, one of them has appeared in the sequence before, and the participants had to decide which one it was. In the latter they were shown two different pictures, both of them have appeared before, they had to name the picture that was shown more recently than the other one. The results of this experiment showed that people with lesions in temporal regions have more trouble with the recognition trial and patients with frontal lesions have difficulties with the recency trial since anterior regions are important for sequencing. This is due to the fact that the recognition trial demanded a properly functioning recognition memory, the recency trial a properly functioning memory for item order. These two are dissociable and seem to be processed in different areas of the brain. The frontal lobe is not only important for sequencing but also thought to play a major role for working memory. This idea is supported by the fact that lesions in the lateral regions of the frontal lobe are much more likely to impair the ability of \'keeping things in mind\' than damage to other areas of the frontal cortex do. But this is not the only thing there is to sequencing. For reaching a goal in the best possible way it is important that a person is able to figure out which sequence of actions, which strategy, best suits the purpose, in addition to just being able to develop a correct sequence. This is proven by an experiment called \'Tower of London\' (Shallice, 1982) which is similar to the famous \'Tower of Hanoi\' task with the difference that this task required three balls to be put onto three poles of different length so that one pole could hold three balls, the second one two and the third one only one ball, in a way that a changeable goal position is attained out of a fixed initial position in as few moves as possible. Especially patients with damage to the left frontal lobe proved to work inefficiently and ineffectively on this task. They needed many moves and engaged in actions that did not lead toward the goal. Problems with the interpretation of available information Quite often, if we want to reach a goal, we get hints on how to do it best. This means we have to be able to interpret the available information in terms of what the appropriate strategy would be. For many patients of executive dysfunction this is not an easy thing to do either. They have trouble to use this information and engage in inefficient actions. Thus, it will take them much longer to solve a task than healthy people who use the extra information and develop an effective strategy. Problems with self-criticism and -monitoring The last problem for people with frontal lobe damage we want to present here is the last point in the above list of properties important for proper goal directed behavior. It is the ability to evaluate one\'s actions, an ability that is missing in most patients. These people are therefore very likely to \'wander off task\' and engage in behavior that does not help them to attain their goal. In addition to that, they are also not able to determine whether their task is already completed at all. Reasons for this are thought to be a lack of motivation or lack of concern about one\'s performance (frontal lobe damage is usually accompanied by changes in emotional processing) but these are probably not the only explanations for these problems. Another important brain region in this context -- the medial portion of the frontal lobe -- is responsible for detecting behavioral errors made while working towards a goal. This has been shown by ERP experiments where there was an error-related negativity 100ms after an error has been made. If this area is damaged, this mechanism cannot work properly any more and the patient loses the ability to detect errors and thus monitor his own behavior. However, in the end we must add that although executive dysfunction causes an enormous number of problems in behaving correctly towards a goal, most patients when assigned with a task are indeed anxious to solve it but are just unable to do so. 2. _Error correction and trouble shooting_ !Figure 10, Example for the WCST: Cards sorted according to shape (a), number (b) or color (c) of the objects, number (b) or color (c) of the objects"){width="350"} The most famous experiment to investigate error correction and trouble shooting is the Wisconsin Card Sorting Test (WCST). A participant is presented with cards that show certain objects. These cards are defined by shape, color and number of the objects on the cards. These cards now have to be sorted according to a rule based on one of these three criteria. The participant does not know which rule is the right one but has to reach the conclusion after positive or negative feedback of the experimenter. Then at some point, after the participant has found the correct rule to sort the cards, the experimenter changes the rule and the previous correct sorting will lead to negative feedback. The participant has to realize the change and adapt to it by sorting the cards according to the new rule. Patients with executive dysfunction have problems identifying the rule in the first place. It takes them noticeably longer because they have trouble using already given information to make a conclusion. But once they got to sorting correctly and the rule changes, they keep sorting the cards according to the old rule although many of them notice the negative feedback. They are just not able to switch to another sorting-principle, or at least they need many tries to learn the new one. They perseverate. Problems in shifting and modifying strategies Intact neuronal tissue in the frontal lobe is also crucial for another executive function connected with goal directed behavior that we described above: Flexibility and adaptability. This means that persons with frontal lobe damage will have difficulties in shifting their way of thinking -- meaning creating a new plan after recognizing that the original one cannot be carried out for some reason. Thus, they are not able to modify their strategy according to this new problem. Even when it is clear that one hypothesis cannot be the right one to solve a task, patients will stick to it nevertheless and are unable to abandon it (called \'tunnel vision\'). Moreover, such persons do not use as many appropriate hypotheses for creating a strategy as people with damage to other brain regions do. In what particular way this can be observed in patients can again not be stated in general but depends on the nature of the shift that has to be made. These earlier described problems of \'redirecting\' of one\'s strategies stand in contrast to the actual \'act of switching\' between tasks. This is yet another problem for patients with frontal lobe damage. Since the control system that leads task switching as such is independent from the parts that actually perform these tasks, the task switching is particularly impaired in patients with lesions to the dorsolateral prefrontal cortex while at the same time they have no trouble with performing the single tasks alone. This of course, causes a lot of problems in goal directed behavior because as it was said before: Most tasks consist of smaller subtasks that have to be completed. 3. _Responses containing novel sequences of actions_ Many clinical tests have been done, requiring patients to develop strategies for dealing with novel situations. In the Cognitive Estimation Task (Shallice & Evans, 1978) patients are presented with questions whose answers are unlikely to be known. People with damage to the prefrontal cortex have major difficulties to produce estimates for questions like: "How many camels are in Holland?". In the FAS Test (Miller, 1984) subjects have to generate sequences of words (not proper names) beginning with a certain letter ("F" , "A" or "S") in a one-minute period. This test involves developing new strategies, selecting between alternatives and avoiding repeating previous given answers. Patients with left lateral prefrontal lesions are often impaired (Stuss et al., 1998). 4. _Technical difficulties or dangerous circumstances_ One single mistake in a dangerous situation may easily lead to serious injuries while a mistake in a technical difficult situation (e.g. building a house of cards) would obviously lead to failure. Thus, in such situations, automatic activation of responses clearly would be insufficient and executive functions seem to be the only solution for such problems. Wilkins, Shallice and McCarthy (1987) were able to prove a connection between dangerous or difficult situations and the prefrontal cortex, as patients with lesions to this area were impaired during experiments concerning dangerous or difficult situations. The ventromedial and orbitofrontal cortex may be particularly important for these aspects of executive functions. 5. _Control of action or the overcoming of strong habitual responses_ Deficits in initiation, cessation and control of action We start by describing the effects of the loss of the ability to start something, to initiate an action. A person with executive dysfunction is likely to have trouble beginning to work on a task without strong help from the outside, while people with left frontal lobe damage often show impaired spontaneous speech and people with right frontal lobe damage rather show poor nonverbal fluency. Of course, one reason is the fact that this person will not have any intention, desire or concern on his or her own of solving the task since this is yet another characteristic of executive dysfunction. But it is also due to a psychological effect often connected with the loss of properly executive functioning: Psychological inertia. Like in physics, inertia in this case means that an action is very hard to initiate, but once started, it is again very hard to shift or stop. This phenomenon is characterized by engagement in repetitive behavior, is called perseveration (cp. WCST). Another problem caused by executive dysfunction can be observed in patients suffering from the so called environmental dependency syndrome. Their actions are impelled or obligated by their physical or social environment. This manifests itself in many different ways and depends to a large extent on the individual's personal history. Examples are patients who begin to type when they see a computer key board, who start washing the dishes upon seeing a dirty kitchen or who hang up pictures on the walls when finding hammer, nails and pictures on the floor. This makes these people appear as if they were acting impulsively or as if they have lost their 'free will'. It shows a lack of control for their actions. This is due to the fact that an impairment in their executive functions causes a disconnection between thought and action. These patients know that their actions are inappropriate but like in the WCST, they cannot control what they are doing. Even if they are told by which attribute to sort the cards, they will still keep sorting them sticking to the old rule due to major difficulties in the translation of these directions into action. What is needed to avoid problems like these are the abilities to start, stop or change an action but very likely also the ability to use information to direct behavior. #### Deficits in cognitive estimation Next to the difficulties to produce estimates to questions whose answers are unlikely known, patients with lesions to the frontal lobes have problems with cognitive estimation in general. Cognitive estimation is the ability to use known information to make reasonable judgments or deductions about the world. Now the inability for cognitive estimation is the third type of deficits often observed in individuals with executive dysfunction. It is already known that people with executive dysfunction have a relatively unaffected knowledge base. This means they cannot retain knowledge about information or at least they are unable to make inferences based on it. There are various effects which are shown on such individuals. Now for example patients with frontal lobe damage have difficulty estimating the length of the spine of an average woman. Making such realistic estimations requires inferencing based on other knowledge which is in this case, knowing that the height of the average woman is about 5 ft 6 in (168 cm) and considering that the spine runs about one third to one half the length of the body and so on. Patients with such a dysfunction do not only have difficulties in their estimates of cognitive information but also in their estimates of their own capacities (such as their ability to direct activity in goal -- oriented manner or in controlling their emotions). Prigatuno, Altman and O'Brien (1990) reported that when patients with anterior lesions associated with diffuse axonal injury to other brain areas are asked how capable they are of performing tasks such as scheduling their daily activities or preventing their emotions from affecting daily activities, they grossly overestimate their abilities. From several experiments Smith and Miler (1988) found out that individuals with frontal lobe damages have no difficulties in determining whether an item was in a specific inspection series they find it difficult to estimate how frequently an item did occur. This may not only reflect difficulties in cognitive estimation but also in memory task that place a premium on remembering temporal information. Thus both difficulties (in cognitive estimation and in temporal sequencing) may contribute to a reduced ability to estimate frequency of occurrence. Despite these impairments in some domains the abilities of estimation are preserved in patients with frontal lobe damage. Such patients also do have problems in estimating how well they can prevent their emotions for affecting their daily activities. They are also as good at judging how many dues they will need to solve a puzzle as patients with temporal lobe damage or neurologically intact people. ------------------------------------------------------------------------ #### Theories of frontal lobe function in executive control In order to explain that patients with frontal lobe damage have difficulties in performing executive functions, four major approaches have developed. Each of them leads to an improved understanding of the role of frontal regions in executive functions, but none of these theories covers all the deficits occurred. Role of working memory The most anatomically specific approach assumes the dorsolateral prefrontal area of the frontal lobe to be critical for working memory. The working memory which has to be clearly distinguished from the long term memory keeps information on-line for use in performing a task. Not being generated for accounting for the broad array of dysfunctions it focuses on the three following deficits: 1. Sequencing information and directing behavior toward a goal 2. Understanding of temporal relations between items and events 3. Some aspects of environmental dependency and perseveration Research on monkeys has been helpful to develop this approach (the delayed-response paradigm, Goldman-Rakic, 1987, serves as a classical example). Role of Controlled Versus Automatic Processes There are two theories based on the underlying assumption that the frontal lobes are especially important for controlling behavior in non-experienced situations and for overriding stimulus-response associations, but contribute little to automatic and effortless behavior (Banich, 1997). Stuss and Benson (1986) consider control over behavior to occur in a hierarchical manner. They distinguish between three different levels, of which each is associated with a particular brain region. In the first level sensory information is processed automatically by posterior regions, in the next level (associated with the executive functions of the frontal lobe) conscious control is needed to direct behavior toward a goal and at the highest level controlled self-reflection takes place in the prefrontal cortex. This model is appropriate for explaining deficits in goal-oriented behavior, in dealing with novelty, the lack of cognitive flexibility and the environmental dependency syndrome. Furthermore it can explain the inability to control action consciously and to criticise oneself. The second model developed by Shalice (1982) proposes a system consisting of two parts that influence the choice of behavior. The first part, a cognitive system called contention scheduling, is in charge of more automatic processing. Various links and processing schemes cause a single stimulus to result in an automatic string of actions. Once an action is initiated, it remains active until inhibited. The second cognitive system is the supervisory attentional system which directs attention and guides action through decision processes and is only active "when no processing schemes are available, when the task is technically difficult, when problem solving is required and when certain response tendencies must be overcome" (Banich , 1997). This theory supports the observations of few deficits in routine situations, but relevant problems in dealing with novel tasks (e.g. the Tower of London task, Shallice, 1982), since no schemes in contention scheduling exist for dealing with it. Impulsive action is another characteristic of patients with frontal lobe damages which can be explained by this theory. Even if asked not to do certain things, such patients stick to their routines and cannot control their automatic behavior. Use of Scripts The approach based on scripts, which are sets of events, actions and ideas that are linked to form a unit of knowledge was developed by Schank (1982) amongst others. Containing information about the setting in which an event occurs, the set of events needed to achieve the goal and the end event terminating the action. Such managerial knowledge units (MKUs) are supposed to be stored in the prefrontal cortex. They are organized in a hierarchical manner being abstract at the top and getting more specific at the bottom. Damage of the scripts leads to the inability to behave goal-directed, finding it easier to cope with usual situations (due to the difficulty of retrieving a MKU of a novel event) and deficits in the initiation and cessation of action (because of MKUs specifying the beginning and ending of an action.) Role of a goal list The perspective of artificial intelligence and machine learning introduced an approach which assumes that each person has a goal list, which contains the tasks requirements or goals. This list is fundamental to guiding behavior and since frontal lobe damages disrupt the ability to form a goal list, the theory helps to explain difficulties in abstract thinking, perceptual analysis, verbal output and staying on task. It can also account for the strong environmental influence on patients with frontal lobe damages, due to the lack of internal goals and the difficulty of organizing actions toward a goal. ------------------------------------------------------------------------ Brain Region Possible Function (left hemisphere) Possible Function (right hemisphere) Brodman\'s Areas which are involved --------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------------------------------- -------------------------------------- ventrolateral prefrontal cortex (VLPFC) Retrieval and maintenance of semantic and/or linguistic information Retrieval and maintenance of visuospatial information 44, 45, 47 (44 & 45 = Broca\'s Area) dorsolateral prefrontal cortex )DLPRF) Selecting a range of responses and suppressing inappropriate ones; manipulating the contents of working memory Monitoring and checking of information held in mind, particularly in conditions of uncertainty; vigilance and sustained attention 9, 46 anterior prefrontal cortex; frontal pole; rostral prefrontal cortex Multitasking; maintaining future intentions & goals while currently performing other tasks or subgoals same 10 anterior cingulate cortex (dorsal) Monitoring in situations of response conflict and error detection same 24 (dorsal) & 32 (dorsal) ## Summary It is important to keep in mind that reasoning and decision making are closely connected to each other: Decision making in many cases happens with a previous process of reasoning. People\'s everyday life is decisively coined by the synchronized appearance of these two human cognitive features. This synchronization, in turn, is realized by the executive functions which seem to be mainly located in the frontal lobes of the brain. ## References •Krawczyk,Daniel (2018). Reasoning: The Neuroscience of How We Think. Elsevier. Goldstein, E. Bruce (2005). Cognitive Psychology - Connecting, Mind Research, and Everyday Experience. Thomson Wadsworth. • Marie T. Banich (1997). Neuropsychology. The neural bases of Mental Function. Houghton Mifflin. • Wilson, Robert A.& Keil, Frank C. (1999). The MIT Encyclopedia of the Cognitive Sciences. Massachusetts: Bradford Book. • Ward, Jamie (2006). The Student\'s Guide To Cognitive Science. Psychology Press. • Levitin, D. J.(2002). Foundations of Cognitive Psychology. • Schmalhofer, Franz. Slides from the course: Cognitive Psychology and Neuropsychology, Summer Term 2006/2007, University of Osnabrueck ## Links Reasoning Quizz to check whether you understood the difference of deduction and induction Short text with graphics Reasoning in geometry Euler circles Wason Selection Task Difference: Induction, Deduction Decision making How to make good decisions Making ethical decisions Web-published journal by the Society for Judgement and Decision Making Executive functions Elaborate document (pdf) from the Technical University of Dresden (in German) Text from the Max Planck Society, Munich (in English) Short description and an extensive link list Executive functions & ADHD
# Cognitive Psychology and Cognitive Neuroscience/Present and Future of Research +:------------------------------+:----:+------------------------------:+ \| Previous \| [O \| Next Chapter \| \| Chapter \| niti \| \| \| \| ve_P \| \| \| \| sych \| \| \| \| olog \| \| \| \| y_an \| \| \| \| d_Co \| \| \| \| gnit \| \| \| \| ive_ \| \| \| \| Neur \| \| \| \| osci \| \| \| \| ence \| \| \| \| "wi \| \| \| \| kili \| \| \| \| nk") \| \| +-------------------------------+------+-------------------------------+ about the future.\"* Robert Storm Petersen ## Introduction / Until now Developing from the information processing approach, present cognitive psychology differs from classical psychological approaches in the methods used as well as in the interdisciplinary connections to other sciences. Apart from rejecting introspection as a valid method to analyse mental phenomena, cognitive psychology introduces further, mainly computer-based, techniques which have not been in the range of classical psychology by now. By using brain-imaging-techniques like fMRI, cognitive psychology is able to analyse the relation between the physiology of the brain and mental processes. In the future, cognitive psychology will likely focus on computer-based methods even more. Thus, the field will profit from improvements in the area of IT. For example, contemporary fMRI scans are plagued by many possible sources of error, which should be solved in the future, thereby improving the power and precision of the technique. In addition, computational approaches can be combined with classical behavioural approaches, where one infers a participant\'s mental states from exhibited behaviour. Cognitive psychology, however, does not only rely on methods developed by other branches of science. It also collaborates with closely related fields, including artificial intelligence, neuroscience, linguistics and the philosophy of mind. The advantage of this multidisciplinary approach is clear: different perspectives on the topic make it possible to test hypotheses using different techniques and to eventually develop new conceptual frameworks for thinking about the mind. Often, modern studies of cognitive psychology criticise classical information processing approaches, which opens the door for other approaches to acquire additional importance. For example, the classical approach has been modified to a parallel information processing approach, which is thought to be closer to the actual functioning of the brain. ## Today\'s approaches ### The momentary usage of brain imaging How are the known brain imaging methods used? What kind of information can be derived using this methods? #### fMRI fMRI is an non-invasive imaging method that pictures active structures of the brain in a high spatial resolution. For that the participant has to lie in a tube and his brain is pictured. While doing a task active structures in the brain of the participant can be recognised on the recordings. How?\ If parts of the brain are active, the metabolism is also stimulated. The blood, that has an important function in the metabolic transport is flowing to the active nerve cells. The haemoglobin in the red blood cells carries oxygen (oxyhaemogliobin) when flowing to the part that is active and that needs oxygen, to consume and work. With consumption the haemoglobin „delivers" the oxygen (desoxyhaemoglobin). This leads to local changes in the relative concentration of oxyhemoglobin and desoxyhemoglobin and changes in local blood volume and blood flow. While haemoglobin is oxygenated it is diamagnetic (meaning the material tends to leave the magnetic field), but paramagnetic (material tends to migrate into the magnetic field) while desoxygenated. The magnetic resonance signal of blood is therefore slightly different depending on the level of oxygenation. By being able to detect the magnetic properties mentioned above, the fMRI-scanner is able to determine alterations in blood flow and blood volume, and construct a picture. This picture shows the brain and its activated parts. While the participant is doing a task the researcher can derive, which brain regions are involved. This is an indirect measure, as the metabolism is measured and not the neuronal activity itself. Furthermore this imaging method has good spatial resolution(where the activity occurs) but low temporal resolution (when the activity occurs), as measurements occur after the neuronal activity. #### EEG The Electroencephalogram (EEG) is another non-invasive brain imaging method. Electronic signals from the human brain are recorded while the participant is doing a task. The electronic activity of the neuronal cells, that is adding can be measured. The electronic activity is measured by attaching electrodes to the skin of the head. In most cases the electrodes are installed on a cap, that the participant wears. It is very time-consuming to install the cap correctly on the head of the participant, but it is very important for the outcome, that everything is in the right place. To assure the adding of the signals the electrodes have to be installed geometric and in a parallel configuration. This technique is applied to measure the event-related potential (ERP), potential changes. They are correlated temporal to an emotional, sensoric, cognitive or motoric event. In the experiment a certain event has to be repeated again and again. The type ERP then can be extracted and calculated. This method is not only time-consumptive, also a lot of disrupting factors complicate the measuring. Moreover this method has a very high temporal resolution, but a very low spatial resolution. It is hardly possible to measure activity in deeper brain regions or to detect the source of the activity interpreting only the recordings. ### Interdisciplinary Approaches #### Cognitive Science Cognitive science is multidisciplinary science. It comprises areas of cognitive psychology, linguistics, neuroscience, artificial intelligence, cognitive anthropology, computer science and philosophy. Cognitive science concentrates to study the intelligent behaviour of humans, which includes perception, learning, memory, thought and language. Research in cognitive sciences are based on naturalistic research methods such as cognitive neuropsychology, introspection, psychological experimentation, mathematical modelling and philosophical argumentation. In the beginning of the cognitive sciences the most common method was introspection. It meant that the test subject evaluated his or her own cognitive thinking. In these experiments the researchers were using experienced subjects because they had to analyse and report their own cognitive thinking. Problems can occur when the results are interpreted and the subject has different reports from the same action. Obviously a clear separation is needed between the matters that can be studied by introspection and the ones that are not adequate for this method. Computational modelling in cognitive science means that the mind is seen as a machine. This approach seeks to express theoretical ideas through computational modelling that generate behaviour similar to humans. Mathematical modelling is based on flow charts. The model\'s quality is very important to ensure the equivalence of the input and results. Nowadays the researchers in cognitive sciences use often theoretical and computational models. \"This does not exclude their primary method of experimentation with human participants. In cognitive sciences it is also important to bring the theories and the experimenting together. Because it comprises so many fields of science it is important to bring together the most appropriate methods from all these fields. The psychological experiments should be interpreted through a theory that expresses mental representations and procedures. The most productive and revealing way to perform research in cognitive sciences is to combine different approaches and methods together. This ensures overall picture from the research area and it comprises the viewpoints of all the different fields.\" (Thagard, Cognitive Science) Nevertheless Cognitive Science has not yet managed to succeed in bringing the different areas together. Nowadays it is criticised for not establishing a science on its own. Rather few scientist really address themselves as cognitive scientists. Furthermore the basic metaphor of the brain functioning like a computer is challenged as well as the distinctions between their models and nature (cf. Eysenck & Keane, Cognitive Psychology, pp. 519-520). This of course brings up a lot of work for the future. Cognitive Science has to work on better models that explain natural processes and that are reliably able to make predictions. Furthermore these models have to combine multiple mental phenomena. In addition to that a general \"methodology for relating a computational model\'s behaviour to human behaviour\" has to be worked out. Hereby the strength of such models can be increased. Apart from that Cognitive Science needs to establish an identity with prominent researchers that avow themselves to Cognitive Science. And finally its biggest goal, the creation of a general unifying theory of human cognition (see Theory Part), has to be reached (cf. ibid, p. 520). ##### Experimental Cognitive Psychology Psychological experimentation studies mental functions. This is done with indirect methods meaning reasoning. These studies are performed to find causal relations and the factors influencing behaviour. The researcher observes visible actions and makes conclusions based on these observations. Variables are changed one at a time and the effect of this change is being observed. The benefits of experimental researching are that the manipulated factors can be altered in nearly any way the researcher wants. From this point it is finally possible to find causal relations. In being the classical approach within the field of cognitive psychology, experimental studies have been the basis for the development of numerous modern approaches within contemporary Cognitive Psychology. Its empirical methods have been developed and verified over time and the gained results were a foundation for many enhancements contributed to the field of psychology. Taking into consideration the established character of experimental cognitive psychology, one might think that methodological changes are rather negligible. But recent years came up with a discussion concerning the question, whether the results of experimental CP remain valid in the "real world" at all. A major objection is that the artificial environment in an experiment might cause that certain facts and coherences are unintentionally ignored, which is due to the fact that for reasons of clarity numerous factors are suppressed (cf. Eysenck & Keane, Cognitive Psychology, pp. 514--515). A possible example for this is the research concerning attention. Since the attention of the participant is mainly governed by the experimenter's instructions, its focus is basically determined. Therefore \"relatively little is known of the factors that normally influence the focus of attention\" (ibid, p. 514). Furthermore it turns out to be problematic that mental phenomena are often examined in isolation. While trying to make the experimental setup as concise as possible (in order to get clearly interpretable results) one decouples the aspect at issue from adjacent and interacting mental processes. This leads to the problem that the results turn out to be valid in the idealised experimental setting only but not in "real life". Here multiple mental phenomena interact with each other and numerous outer stimuli influence the behaviour of mental processes. The validity gained by such studies could only be characterised as an internal validity (which means that the results are valid in the special circumstances created by the experimenter) but not as an external validity (which means that the results stay valid in changed and more realistic circumstances) (cf. ibid, p. 514). These objections lead to experiments which have been developed to refer closer to \"real life\". According to these experiments \"real-world\" phenomena like \'absent-mindedness\', \'everyday memory\' or \'reading\' gain importance. Nevertheless the discussion remains whether such experiments really deliver new information about mental processes. And whether these \'everyday phenomenon studies\' really become broadly accepted greatly depends on the results current experiments will deliver. Another issue concerning experimental setups in cognitive psychology is the way individual differences are handled. In general the results from an experiment are generated by an analysis of variance. This causes that results which are due to individual differences are averaged out and not taken into further consideration. Such a procedure seems to be highly questionable, especially if put into the context of an investigation of Bowers in 1973, which showed that over 30% of the variance in such studies are due to individual differences or their interaction with the current situation (cf. ibid, p. 515). Based on such facts one challenge for future experimental cognitive psychology is the analysis of individual differences and finding way to include knowledge about such differences in general studies. ##### Cognitive Neuroscience Another approach towards a better understanding of human cognition is cognitive neuroscience. Cognitive neuroscience lies at the interface between traditional cognitive psychology and the brain sciences. It is a science whose approach is characterised by attempts to derive cognitive level theories from various types of information, such as computational properties of neural circuits, patterns of behavioural damage as a result of brain injury or measurements of brain activity during the execution of cognitive tasks (cf. www.psy.cmu.edu). Cognitive neuroscience helps to understand how the human brain supports thought, perception, affection, action, social process and other aspects of cognition and behaviour, including how such processes develop and change in the brain over time (cf. www.nsf.gov). Cognitive neuroscience has emerged in the last decade as an intensely active and influential discipline, forged from interactions among the cognitive sciences, neurology, neuroimaging, physiology, neuroscience, psychiatry, and other fields. New methods for non-invasive functional neuroimaging of subjects performing psychological tasks have been of particular importance for this discipline. Non-invasive functional neuroimaging includes: positron emission tomography (PET), functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), optical imaging (near infra-red spectroscopy or NIRS), anatomical MRI, and diffusion tensor imaging (DTI) The findings of cognitive neuroscience are directed towards enabling a basic scientific understanding of a broad range of issues involving the brain, cognition and behaviour. (cf. www.nsf.gov). Cognitive neuroscience becomes a very important approach to understand human cognition, since results can clarify functional brain organisation, such as the operations performed by a particular brain area and the system of distributed, discrete neural areas supporting a specific cognitive representation. These findings can reveal the effect on brain organization of individual differences (including even genetic variation) (cf. www.psy.cmu.edu, www.nsf.gov). Another importance of cognitive neuroscience is that cognitive neuroscience provides some ways that allow us to \"obtain detailed information about the brain structures involved in different kinds of cognitive processing\" (Eysenck & Keane, Cognitive Psychology, p. 521). Techniques such as MRI and CAT scans have proved of particular value when used on patients to discover which brain areas are damaged. Before non-invasive methods of cognitive neuroscience were developed localisation of \"brain damage could only be established by post mortem examination\" (ibid). Knowing which brain areas are related to which cognitive process would surely lead to obtain a clearer view of brain region, hence, in the end would help for a better understanding of human cognition processes. Another strength of cognitive neuroscience is that it serves as a tool to demonstrate the reality of theoretical distinctions. For example, it has been argued by many theorists that implicit memory can be divided into perceptual and conceptual implicit memory; support for that view has come from PET studies, which show that perceptual and conceptual priming tasks affected different areas of the brain (cf. ibid, pp. 521-522). However, cognitive neuroscience is not that perfect to be able to stand alone and answer all questions dealing with human cognition. Cognitive neuroscience has some limitations, dealing with data collecting and data validity. In most neuroimaging studies, data is collected from several individuals and then averaged. Some concern has arose about such averaging because of the existence of significant individual differences. Though the problem was answered by Raichle (1998), who stated that the differ in individual brain should be appreciated, however general organising principles emerge that transcend these differences, a broadly accepted solution to the problem has yet to be found (cf. ibid, p. 522). ##### Cognitive Neuropsychology Cognitive Neuropsychology maps the connection between brain functions and cognitive behaviour. Patients with brain damages have been the most important source of research in neuropsychology. Neuropsychology also examines dissociation ("forgetting"), double dissociation and associations (connection between two things formed by cognition). Neuropsychology uses technological research methods to create images of the brain functioning. There are many differences in techniques to scan the brain. The most common ones are EEG (Electroencephalography), MRI and fMRI (functional Magnetic Resonance Imaging) and PET (Positron Emission Tomography). Cognitive Neuropsychology became very popular since it delivers good evidence. Theories developed for normal individuals can be verified by patients with brain damages. Apart from that new theories could have been established because of the results of neuropsychological experiments. Nevertheless certain limitations to the approach as it is today cannot be let out of consideration. First of all the fact that people having the same mental disability often do not have the same lesion needs to be pointed out (cf. ibid, pp.516-517). In such cases the researchers have to be careful with their interpretation. In general it could only be concluded that all the areas that the patients have injured could play a role in the mental phenomenon. But not which part really is decisive. Based on that future experiments in this area tend to make experiments with a rather small number of people with pretty similar lesion respectively compare the results from groups with similar syndromes and different lesions. In addition to that the situation often turns out to be vice versa. Some patients do have pretty similar lesions but show rather different behaviour (cf. ibid, p.517). One probable reason therefore is that the patients differ in their age and lifestyle (cf. Banich, Neuropsychology, p.55). With better technologies in the future one will be better able to distinguish the cases in which really the various personalities make the difference or in which cases the lesions are not entirely equal. In addition to that the individual brain structures which may cause the different reactions to the lesions will become a focus of research. Another problem for Cognitive Neuropsychology is that their patients are rare. The patients which are interesting for such research have lesions of an accident or suffered during war. But in addition there are differences in the manner of the lesion. Often multiple brain regions are damaged which makes it very hard to determine which of them is responsible for the examined phenomenon. The dependency on chance whether there are available patients will remain in future. Thereby predictions concerning this aspect of the research are not very reliable. Apart from that it is not possible yet to localise some mental processes in the brain. Creative thought or organisational planning are examples (cf. Eysenck & Keane, Cognitive Psychology, p.517). A possible outcome of the research is that those activities rely on parallel processing. This would support the idea of the modification of the information processing theory that will be discussed later on. But if it shows up that a lot of mental processes depend on such parallel processing it would turn out to be a big drawback for Cognitive Psychology since its core is the modularization of the brain and the according phenomena. In this context the risk of overestimation and underestimation has to be mentioned. The latter occurs because Cognitive Psychology often only identifies the most important brain region for the mental task. Other regions that are related thereto could be ignored. This could turn out to be fundamental if really parallel processing is crucial to many mental activities. Overestimation occurs when fibers that only pass the damaged brain region are lesioned, too. The researcher concludes that the respective brain region plays an important role in the phenomenon he analyses even though only the deliverance of the information passed that region (cf. ibid). Modern technologies and experiments here have to be developed in order to provide valid and precise results. #### Unifying Theories A unified theory of cognitive science serves the purpose to bring together all the vantage points one can take toward the brain/mind. If a theory could be formed which incorporates all the discoveries of the disciplines mentioned above a full understanding would be tangible. ##### ACT-R ACT-R is a Cognitive Architecture, an acronym for Adaptive Control of Thought--Rational. It provides tools which enable us to model the human cognition. It consists mainly of five components: Perceptual-motor modules, declarative memory, procedural memory, chunks and buffers. The declarative memory stores facts in "knowledge-units", the chunks. These are transmitted through the modules respective buffers, which contain one chunk at a time. The procedural memory is the only one without an own buffer, but is able to access the contents of the other buffers. For example those of the perceptual-motor modules, which are the interface with the (simulated) outer world. Production is accomplished by predefined rules, written is LISP. The main character behind it is John R. Anderson who tributes the inspiration to Allan Newell. ##### SOAR SOAR is another Cognitive Architecture, an acronym for State, Operator And Result. It enables one to model complex human capabilities. Its goal is to create an agent with human-like behaviour. The working principles are the following: Problem-solving is a search in a problem-space. Permanent Knowledge is represented by production rules in the production memory. Temporary Knowledge is represented by objects in the working memory. New Goals are created only if a dead end is reached. The learning mechanism is Chunking. Chunking: If SOAR encounters an impasse and is unable to resolve it with the usual technique, it uses "weaker" strategies to circumvent the dead end. In case one of these attempts leads to success, the respective route is saved as a new rule, a chunk, preventing the impasse to occur again. SOAR was created by John Laird, Allen Newell and Paul Rosenbloom. #### Neural Networks There are two types of neural networks: biological and artificial. A biological NN consists of neurons which are physically or functionally connected with each other. Since each neuron can connect to multiple other neurons the number of possible connections is exponentially high. The connections between neurons are called synapses. Signalling along these synapses happens via electrical signalling or chemical signalling, which induces electrical signals. The chemical signalling works by various neurotransmitters. Artificial NN are divided by their goals. One is that of artificial intelligence and the other cognitive modelling. Cognitive modelling NN try to simulate biological NN in order to gain better understanding of them, for example the brain. Until now the complexity of the brain and similar structures has prevented a complete model from being devised, so the cognitive modelling focuses on smaller parts like specific brain regions. NNs in artificial intelligence are used to solve distinct problems. But though their goals differ the methods applied are very similar. An artificial NN consist of artificial neurons (nodes) which are connected by mathematical functions. These functions can be of other functions which in turn can be of yet other functions and so on. The actual work is done by following the connections according to their weights. Weights are properties of the connections defining the probability of the specific route to be taken by the program and can be changed by it, thus optimizing the main function. Hereby it is possible to solve problems for which it is impossible to write a function "by hand". ## Future Research #### Brain imaging/activity measuring As described in section 2.1. and 2.2. there are disadvantages of the brain imaging methods. fMRI has a low temporal resolution, but EEG a low spatial resolution. An interdisciplinary attempt is to combine both methods, to reach both a high spatial and temporal resolution. This technique (simultaneous EEG-measuring in the fMR) is used for instance in studying children with extratemporal epilepsy. It is important to assign the temporal progress to a region in which the epileptic seizure has its roots. In December 2006 a conference in Munich discussed another idea of this mixture of methods: the study of Alzheimer\'s disease. It could be possible to recognise this disease very early. This could lead to new therapies to reduce the speed and the amount of cell-dead. In December of 2006 a conference in Munich discussed this eventuality. Brain imaging methods are not only useful in medical approaches. Other disciplines could benefit from the brain imaging methods and derive new conclusions. For instance for social psychologist the brain imaging methods are interesting. Experiments with psychopathic personalities are only one possibility to explore the behaviour of humans. For literature scientists there could be a possibility to study stylistic devices and their effect of humans while reading a poem. Another attempt in future research is to synchronise the direction of sight and the stimuli, that was trigger for the change of direction. This complex project needs data from eye-tracking experiments and data from fMRI-studies. #### Unifying theories more unifying. Since the mind is a single system it should be possible to explain it as such without having to take different perspectives for every approach (neurological,psychological,computational). Having such a theory would enable us to understand our brain far more thorough than now, and might eventually lead an everyday application. But until now there is no working Unifying Theory of Cognition, which fulfils the requirements stated by Allen Newell in his book Unified Theories of Cognition. Accordingly a UTC has to explain: How intelligent organisms respond flexibly to the environment. How they exhibit goal-directed behaviour and choose goals rationally (and in response to interrupts: see previous point). How they use symbols. How they learn from experience. Even Newells own implementation SOAR does not reach these goals. ### Promising experiments Here I collected the abstracts of a few recent findings, feel free to modify or add to them. \>\>Unintentional language switch \[\] Kho, K.H., Duffau, H., Gatignol, P., Leijten, F.S.S., Ramsey, N.F., van Rijen, P.C. & Rutten, G-J.M. (2007) Utrecht Abstract 1 We present two bilingual patients without language disorders in whom involuntary language switching was induced. The first patient switched from Dutch to English during a left-sided amobarbital Wada-test. Functional magnetic resonance imaging yielded a predominantly left-sided language distribution similar for both languages. The second patient switched from French to Chinese during intraoperative electrocortical stimulation of the left inferior frontal gyrus. We conclude that the observed language switching in both cases was not likely the result of a selective inhibition of one language, but the result of a temporary disruption of brain areas that are involved in language switching. These data complement the few lesion studies on (involuntary or unintentional) language switching, and add to the functional neuroimaging studies of switching, monitoring, and controlling the language in use. \>\>Bilateral eye movement -\> memory Parker, A. & Dagnall, N. (2007) Manchester Metropolitan University, One hundred and two participants listened to 150 words, organised into ten themes (e.g. types of vehicle), read by a male voice. Next, 34 of these participants moved their eyes left and right in time with a horizontal target for thirty seconds (saccadic eye movements); 34 participants moved their eyes up and down in time with a vertical target; the remaining participants stared straight ahead, focussed on a stationary target. After the eye movements, all the participants listened to a mixture of words: 40 they\'d heard before, 40 completely unrelated new words, and 10 words that were new but which matched one of the original themes. In each case the participants had to say which words they\'d heard before, and which were new. The participants who\'d performed sideways eye movements performed better in all respects than the others: they correctly recognised more of the old words as old, and more of the new words as new. Crucially, they were fooled less often by the new words whose meaning matched one of the original themes - that is they correctly recognised more of them as new. This is important because mistakenly identifying one of these \'lures\' as an old word is taken as a laboratory measure of false memory. The performance of the participants who moved their eyes vertically, or who stared ahead, did not differ from each other. Episodic memory improvement induced by bilateral eye movements is hypothesized to reflect enhanced interhemispheric interaction, which is associated with superior episodic memory (S. D. Christman & R. E. Propper. 2001). Implications for neuropsychological mechanisms underlying eye movement desensitization and reprocessing (F. Shapiro, 1989, 2001), a therapeutic technique for posttraumatic stress disorder, are discussed \>\>is the job satisfaction--job performance relationship spurious? A meta-analytic examination Nathan A. Bowling(Department of Psychology, Wright State University) Abstract 2 The job satisfaction--job performance relationship has attracted much attention throughout the history of industrial and organizational psychology. Many researchers and most lay people believe that a causal relationship exists between satisfaction and performance. In the current study, however, analyses using meta-analytic data suggested that the satisfaction--performance relationship is largely spurious. More specifically, the satisfaction--performance relationship was partially eliminated after controlling for either general personality traits (e.g., Five Factor Model traits and core self-evaluations) or for work locus of control and was almost completely eliminated after controlling for organization-based self-esteem. The practical and theoretical implications of these findings are discussed. \>\>Mirror-touch synesthesia is linked with empathy Michael J Banissy & Jamie Ward (Department of Psychology, University College London) Abstract 3 Watching another person being touched activates a similar neural circuit to actual touch and, for some people with \'mirror-touch\' synesthesia, can produce a felt tactile sensation on their own body. In this study, we provide evidence for the existence of this type of synesthesia and show that it correlates with heightened empathic ability. This is consistent with the notion that we empathize with others through a process of simulation. ### Discussion points Where are the limitations of research? Can we rely on our intuitive idea of our mind? What impact could a complete understanding of the brain have on everyday life? #### Brain activity as a false friend In several experiments the outcome is not unambiguous. This hinders a direct derivation from the data. In experiments with psychopathic personalities researchers had to weaken their thesis, that persons with missing activity in the frontal lobe are predetermined for being violent psychopathic people, that are unethical murderers. Missing activity in the frontal lobe leads to a disregulation of threshold for emotional, impulsive or violent actions. But this also advantages for example fire fighters or policemen, who have to withstand strong pressures and who need a higher threshold. So missing activity is not a sufficient criterion for psychopathic personalities. ## Conclusion Today\'s work in the field of Cognitive Psychology gives several hints how future work in this area may look like. In practical applications improvements will probably mainly be driven by the limitations one faces today. Here in particular the newer subfields of Cognitive Psychology will develop quickly. How such changes look like heavily depends on the character of future developments in technology. Especially improvements in Cognitive Neuropsychology and Cognitive Neuroscience depend on the advancements of the imaging techniques. In addition to that the theoretical framework of the field will be influenced by such developments. The parallel processing theory may still be modified according to new insights in computer science. Thereby or eventually by the acceptance of one of the already existing overarching theories the theoretical basis for the current research could be reunified. But if it takes another 30 years to fulfil Newell\'s dream of such a theory or if it will happen rather quick is still open. As a rather young science Cognitive Psychology still is subject to elementary changes. All its practical and theoretical domains are steadily modified. Whether the trends mentioned in this chapter are just dead ends or will cause a revolution of the field could only be predicted which definitely is hard. ## References 4 5 6 7 8 9 10 11 Anderson, John R., Lebiere, Christian, The Atomic Components of Thought, Lawrence Erlbaum Associates, 1998\ Banich, Marie T., Neuropsycology - The Neural Bases of Mental Function, Hougthon Mifflin Company, 1997\ E. Br. Goldstein, Cognitive Psychology, Wadsworth, 2004\ Lyon, G.Reid, Rumsey, Judith M.: Neuroimaging. A Window to Neurological Foundations of Learning and Behaviour in Children. Baltimore. 1996.\ M. W. Eysenck, M. T. Keane, Cognitive Psychology - A Student\'s Handbook, Psychology Press Ltd, 2000\ Thagard, Paul, Cognitive Science in Edward N. Zalta (ed.), The Stanford Encyclopedia of Philosophy, 2004\ ## Links 12 13
# Cognitive Psychology and Cognitive Neuroscience/Hints for good writing First and most important: Always remember, that we are writing a scientific book, not a novel; an essay; or a wikipedia article. For a start you could read this article Try to write a consistent block of text, using subheadings, paragraphs and footnotes. Do not make listings, keywords and in general _articles_, but chapters. Your first assignment is the introduction to your chapter. Keep in mind that this is the basis for the rest of your chapter. You shouldn\'t later rewrite your Introduction completely, because you did not know what to write. This assignment already counts for your mark. \'\'The mentioned APA Publishing Manual is not online. However, there is a good overview here If you need help, check out the link section or write Iroewer and Aschoeke on their discussion site or via email.
# Cognitive Psychology and Cognitive Neuroscience/Some useful syntax ## Referencing From the Wikipedia about footnotes. On the Edit page, this is placed at the first insertion point of citation: : : \<ref name=\"Perry\"\>Perry\'s Handbook, Sixth Edition, McGraw-Hill Co., 1984.\</ref\> This is placed at the second insertion point of citation: : : \<ref name=\"Perry\"/\> This is placed at the third insertion point of citation: : : \<ref name=\"Perry\"/\> \... and so forth for further insertion points On the Edit page, this is placed in the References or the Footnotes section, so the area, were the footnotes should appear: : : \<references/\>
# Cognitive Psychology and Cognitive Neuroscience/Cross References The group Cross References responsibility is to make sure, that the chapter are related to each other and that the mentioning of source is not redundant. It will also help to connect groups which have similar topics and may work together on certain issues. The group works together with OverallStructure, to ensure that the book in its final state is consistent, but the CRG will concentrate more on sources and team work. Our tools will be mostly non visible in the book, as our work will happen on discussion pages, email and other not wiki related methods of communication. However, we see our work as most important, as we have to ensure the scientific mentioning of the sources and have an overview over every page written in this project.
# Cognitive Psychology and Cognitive Neuroscience/OverallStructure ## OverallStructure Our workgroup OverallStructure tries to work out this project of Cognitive Psychology and Cognitive Neuroscience by helping people how to do things right and remind them on the laws that we are all restricted to when we publish. We try to give, the groups that work on this book, useful help, inspiration and to remind them on certain dead-lines. Especially at the end we are going to put the chapters together as one piece, to make this a book worth being published and being read. Working voltage is necessary for a workflow of our project to succeed. A workflow needs to be split up in sub-units. These subunits fill up the work schedule which is necessary to keep track of the workload and to stay in the timeframe. Here it is important to delegate work to different groups and to have us that has an overlook about what needs to be done and when it is due. OverallStructure works with the group CrossReferences closely together. This is required, because otherwise there is the possibility, that we work counterproductive or that we work parallelly on the same thing. Therefor our groups need to find out together what our priorities are and how to put this into practice. Social skills is a highly recommended to work in this group. Remembering and criticizing people is risky field. Our comments need to be productive and not to be offensive. We need close interaction with everybody working on this project, just by that it is possible for us to do the required work. We depend on the different groups and they depend on us. Therefor we need some empathy for the nature of humans. Hence we expect of people working on this project and especially of ourselves: - We estimate people to have critical faculties, are able of some kind of self-reflection, self-discipline and tolerance. - In terms of working in groups, we anticipate everyone to be team-oriented, to cooperate with us and insight of the group, to be discountable, open to use communication skills and we hope to have at least one person in each group with some kind of leader-qualities. OverallStructure emphasizes very much group-work. Working in groups has a lot of advantages: It makes a project being more productive and more flexible. Groups always optimize themselves, because each member of the group enhances the work of the others resulting in improved work-results. Each member harvest their own individuality and their own creativity. A group contains a special selfcheck, each member not cooperating get in some ways punished by the rest of the group. Paraphrasing this we hope to find people being committed to this project. Our group is a very challenging and implies responsibility from both sides for this project to work and to succeed.
# Write Yourself a Scheme in 48 Hours/First Steps First, you\'ll need to install GHC. On GNU/Linux, it\'s often pre-installed or available via the package manager (`apt` or `yum` or `pacman` for example, depending on your distribution). It\'s also downloadable from <http://www.haskell.org/ghc/>. A binary package is probably easiest, unless you really know what you\'re doing. It should download and install like any other software package. This tutorial was developed on GNU/Linux, but everything should also work on Windows, as long as you know how to use the command line, or on the Macintosh from within the Terminal. For UNIX (or Windows Emacs) users, there is a pretty good Emacs mode, including syntax highlighting and automatic indentation. Windows users can use Notepad or any other text editor: Haskell syntax is fairly Notepad-friendly, though you have to be careful with the indentation. Eclipse users might want to try the eclipsefp plug-in. Now, it\'s time for your first Haskell program. This program will read a name off the command line and then print a greeting. Create a file ending in \".hs\" and type the following text. Be sure to get the indentation right, or else it may not compile. ``` haskell module Main where import System.Environment main :: IO () main = do args <- getArgs putStrLn ("Hello, " ++ args !! 0) ``` Let\'s go through this code. The first two lines specify that we\'ll be creating a module named Main that imports the System module. Every Haskell program begins with an action called `main` in a module named `Main`. That module may import others, but it must be present for the compiler to generate an executable file. Haskell is case-sensitive: module names are always capitalized, definitions always uncapitalized. The line `main :: IO ()` is a type declaration: it says that `main` is of type `IO ()`, which is an IO action carrying along values of unit type `()`. A unit type allows only one value, also denoted `()`, thus holding no information. Type declarations in Haskell are optional: the compiler figures them out automatically, and only complains if they differ from what you\'ve specified. In this tutorial, I specify the types of all declarations explicitly, for clarity. If you\'re following along at home, you may want to omit them, because it\'s less to change as we build our program. The IO type is an instance of the Monad class (a class of types). Monad is a concept. To say a value is of a type of the monad class is to say: 1. there is (a certain type of) extra information attached to this value; 2. most functions do not need to worry about these pieces of information. In this example, 1. the \"extra information\" is IO actions to be performed using the carried along values; 2. while the basic value (which attached with information) is void, represented as `()`. Both `IO [String]` and `IO ()` belong to the same `IO` monad type, but they have different base types. They act on (and pass along) values of different types, `[String]` and `()`. \"value attached with (hidden) information\" is called \"Monadic value\". \"Monadic value\" is often called \"actions\", because the easiest way to think about the using of IO monad is to think about a sequence of actions affecting the outside world. The sequence of actions maybe pass along basic values, and each action is able to act on the values. Haskell is a functional language: instead of giving the computer a sequence of instructions to carry out, you give it a collection of definitions that tell it how to perform every function it might need. These definitions use various compositions of actions and functions. The compiler figures out an execution path that puts everything together. To write one of these definitions, you set it up as an equation. The left hand side defines a name, and optionally one or more patterns (explained later) that will bind variables. The right hand side defines some composition of other definitions that tells the computer what to do when it encounters the name. These equations behave just like ordinary equations in algebra: you can always substitute the right hand side for the left within the text of the program, and it\'ll evaluate to the same value. Called \"referential transparency\", this property makes it significantly easier to reason about Haskell programs than other languages. How will we define our `main` action? We know that it must be an `IO ()` action, which we want to read the command line args and print some output, producing `()`, or nothing of value, eventually. There are two ways to create an IO action (either directly or by calling a function that performs them): 1. Lift an ordinary value into the IO monad, using the `return` function. 2. Combine two existing IO actions. Since we want to do two things, we\'ll take the second approach. The built-in action getArgs reads the command-line arguments and passes them along as a list of strings. The built-in function putStrLn takes a string and creates an action that writes this string to the console. To combine these actions, we use a do-block. A do-block consists of a series of lines, all lined up with the first non-whitespace character after the do. Each line can have one of two forms: 1. `name <- action1` 2. `action2` The first form binds the result of action1 to name, to be available in next actions. For example, if the type of action1 is `IO [String]` (an IO action returning a list of strings, as with `getArgs`), then name will be bound in all the subsequent actions to the list of strings thus passed along, through the use of \"bind\" operator `>>=`. The second form just executes action2, sequencing it with the next line (should there be one) through the `>>` operator. The bind operator has different semantics for each monad: in the case of the IO monad, it executes the actions sequentially, performing whatever external side-effects that result from actions. Because the semantics of this composition depend upon the particular monad used, you cannot mix actions of different monad types in the same do-block - only `IO` monad can be used (it\'s all in the same \"pipe\"). Of course, these actions may themselves call functions or complicated expressions, passing along their results (either by calling the `return` function, or some other function that eventually does so). In this example, we first take the first element of the argument list (at index 0, `args !! 0`), concatenate it onto the end of the string \"Hello, \" (`"Hello, " ++`), and finally pass that to `putStrLn` which creates new IO action, participating in the do-block sequencing. A new action thus created, which is a combined sequence of actions as described above, is stored in the identifier `main` of type `IO ()`. The Haskell system notices this definition, and executes the action in it. Strings are lists of characters in Haskell, so you can use any of the list functions and operators on them. A full table of the standard operators and their precedences follows: Operator(s) Precedence Associativity Description ---------------------------------- ------------------------------------ -------------------------------------------------------------- -------------------------------------------------------------------------------------------------- `.` 9 right function composition `<code>`{=html} `</code>`{=html} left list indexing `^`, `^^`, `*` 8 right exponentiation (integer, fractional, and floating-point) ``, `/` 7 left multiplication, division `+`, `-` 6 left addition, subtraction `:` 5 right cons (list construction) `++` right list concatenation `` `elem` ``, `` `notElem` `` 4 left list membership `==`, `/=`, `<`, `<=`, `>=`, `>` left equality, inequality, and other relation operators `&&` 3 right logical and `<code>`{=html}`<nowiki>`{=html} `</nowiki>`{=html}`</code>`{=html} 2 right `>>`, `>>=` 1 left monadic bind ignoring the return value, monadic bind piping value to the next function `=<<` right reverse monadic bind (same as above, but arguments reversed) `$` 0 right infix function application (`f $ x` is the same as `f x`, but right-associative instead of left) To compile and run the program, try something like this: `debian:/home/jdtang/haskell_tutorial/code# ghc -o hello_you --make listing2.hs`\ `debian:/home/jdtang/haskell_tutorial/code# ./hello_you Jonathan`\ `Hello, Jonathan` The `-o` option specifies the name of the executable you want to create, and then you just specify the name of the Haskell source file.
# Write Yourself a Scheme in 48 Hours/Parsing ## Making project scaffolding and getting `parsec` We\'ll be using the Parsec library. To install it, you\'ll need `cabal-install`, which is invoked with the `cabal` command. On Debian/Ubuntu: `sudo apt-get install cabal-install`. Alternatively, you can use ghcup, which works for many platforms. After installing `cabal-install`, let\'s make a project: ``` sh $ cabal update $ mkdir myProject $ cd myProject $ cabal init ``` Now edit `myProject.cabal` such that `parsec` is listed in `build-depends` listing, in addition to `base`. Now, the project can be run using `cabal run`: Building executable 'myProject' for myProject-0.1.0.0.. [1 of 1] Compiling Main ( app/Main.hs ) Linking myProject-0.1.0.0/x/myProject/build/myProject/myProject ... Hello, Haskell! The last line is the output by the program. ## Writing a Simple Parser Now, let\'s try writing a very simple parser. Start by adding these lines to the import section of `app/Main.hs` (which was generated by `cabal init`): ``` haskell import Text.ParserCombinators.Parsec hiding (spaces) import System.Environment ``` This makes the Parsec library functions available to us, except the `spaces` function, whose name conflicts with a function that we\'ll be defining later. Now, we\'ll define a parser that recognizes one of the symbols allowed in Scheme identifiers: ``` haskell symbol :: Parser Char symbol = oneOf "!#$%&\|+-/:<=>?@^_~" ``` This is another example of a monad: in this case, the \"extra information\" that is being hidden is all the info about position in the input stream, backtracking record, first and follow sets, etc. Parsec takes care of all of that for us. We need only use the Parsec library function `oneOf`, and it\'ll recognize a single one of any of the characters in the string passed to it. Parsec provides a number of pre-built parsers: for example, `letter` and `digit` are library functions. And as you\'re about to see, you can compose primitive parsers into more sophisticated productions. Let\'s define a function to call our parser and handle any possible errors: ``` haskell readExpr :: String -> String readExpr input = case parse symbol "lisp" input of Left err -> "No match: " ++ show err Right val -> "Found value" ``` As you can see from the type signature, `readExpr` is a function (`->`) from a `String` to a `String`. We name the parameter `input`, and pass it, along with the `symbol` parser we defined above to the Parsec function `parse`. The second parameter to `parse` is a name for the input. It is used for error messages. `parse` can return either the parsed value or an error, so we need to handle the error case. Following typical Haskell convention, Parsec returns an `Either` data type, using the `Left` constructor to indicate an error and the `Right` one for a normal value. We use a `case...of` construction to match the result of `parse` against these alternatives. If we get a `Left` value (error), then we bind the error itself to `err` and return \"No match\" with the string representation of the error. If we get a `Right` value, we bind it to `val`, ignore it, and return the string \"Found value\". The `case...of` construction is an example of pattern matching, which we will see in much greater detail later on. Finally, we need to change our main function to call `readExpr` and print out the result: ``` haskell main :: IO () main = do (expr:_) <- getArgs putStrLn (readExpr expr) ``` To compile and run this, you can specify the command line parameters after the \"executable target\" which the project scaffolding generated with the call to `init` in the first section. For example: `$ cabal run myProject $`\ `Found value`\ `$ cabal run myProject a`\ `No match: "lisp" (line 1, column 1):`\ `unexpected "a"` ## Whitespace Next, we\'ll add a series of improvements to our parser that\'ll let it recognize progressively more complicated expressions. The current parser chokes if there\'s whitespace preceding our symbol: `$ cabal run myProject " %"`\ `No match: "lisp" (line 1, column 1):`\ `unexpected " "` Let\'s fix that, so that we ignore whitespace. First, lets define a parser that recognizes any number of whitespace characters. Incidentally, this is why we included the `hiding (spaces)` clause when we imported Parsec: there\'s already a `spaces` function in that library, but it doesn\'t quite do what we want it to. (For that matter, there\'s also a parser called `lexeme` that does exactly what we want, but we\'ll ignore that for pedagogical purposes.) ``` haskell spaces :: Parser () spaces = skipMany1 space ``` Just as functions can be passed to functions, so can actions. Here we pass the Parser action `space` to the Parser action `skipMany1`, to get a Parser that will recognize one or more spaces. Now, let\'s edit our parse function so that it uses this new parser: ``` haskell readExpr input = case parse (spaces >> symbol) "lisp" input of Left err -> "No match: " ++ show err Right val -> "Found value" ``` We touched briefly on the `>>` (\"bind\") operator in lesson 2, where we mentioned that it was used behind the scenes to combine the lines of a do-block. Here, we use it explicitly to combine our whitespace and symbol parsers. However, bind has completely different semantics in the Parser and IO monads. In the Parser monad, bind means \"Attempt to match the first parser, then attempt to match the second with the remaining input, and fail if either fails.\" In general, bind will have wildly different effects in different monads; it\'s intended as a general way to structure computations, and so needs to be general enough to accommodate all the different types of computations. Read the documentation for the monad to figure out precisely what it does. Compile and run this code. Note that since we defined `spaces` in terms of `skipMany1`, it will no longer recognize a plain old single character. Instead you have to* precede a symbol with some whitespace. We\'ll see how this is useful shortly: `$ cabal run myProject " %"`\ `Found value`\ `$ cabal run myProject %`\ `No match: "lisp" (line 1, column 1):`\ `unexpected "%"`\ `expecting space`\ `$ cabal run myProject " abc"`\ `No match: "lisp" (line 1, column 4):`\ `unexpected "a"`\ `expecting space` ## Return Values Right now, the parser doesn\'t do much of anything---it just tells us whether a given string can be recognized or not. Generally, we want something more out of our parsers: we want them to convert the input into a data structure that we can traverse easily. In this section, we learn how to define a data type, and how to modify our parser so that it returns this data type. First, we need to define a data type that can hold any Lisp value: ``` haskell data LispVal = Atom String \| List [LispVal] \| DottedList [LispVal] LispVal \| Number Integer \| String String \| Bool Bool ``` This is an example of an algebraic data type: it defines a set of possible values that a variable of type LispVal can hold. Each alternative (called a constructor and separated by `\|`) contains a tag for the constructor along with the type of data that the constructor can hold. In this example, a `LispVal` can be: 1. An `Atom`, which stores a String naming the atom 2. A `List`, which stores a list of other LispVals (Haskell lists are denoted by brackets); also called a proper list 3. A `DottedList`, representing the Scheme form `(a b . c)`; also called an improper list. This stores a list of all elements but the last, and then stores the last element as another field 4. A `Number`, containing a Haskell Integer 5. A `String`, containing a Haskell String 6. A `Bool`, containing a Haskell boolean value Constructors and types have different namespaces, so you can have both a constructor named `String` and a type named `String`. Both types and constructor tags always begin with capital letters. Next, let\'s add a few more parsing functions to create values of these types. A string is a double quote mark, followed by any number of non-quote characters, followed by a closing quote mark: ``` haskell parseString :: Parser LispVal parseString = do char '"' x <- many (noneOf "\"") char '"' return $ String x ``` We\'re back to using the `do`-notation instead of the `>>` operator. This is because we\'ll be retrieving the value of our parse (returned by `many(noneOf "\"")`) and manipulating it, interleaving some other parse operations in the meantime. In general, use `>>` if the actions don\'t return a value, `>>=` if you\'ll be immediately passing that value into the next action, and `do`-notation otherwise. Once we\'ve finished the parse and have the Haskell String returned from `many`, we apply the `String` constructor (from our LispVal data type) to turn it into a `LispVal`. Every constructor in an algebraic data type also acts like a function that turns its arguments into a value of its type. It also serves as a pattern that can be used in the left-hand side of a pattern-matching expression; we saw an example of this in Lesson 3.1 when we matched our parser result against the two constructors in the `Either` data type. We then apply the built-in function `return` to lift our `LispVal` into the `Parser` monad. Remember, each line of a `do`-block must have the same type, but the result of our String constructor is just a plain old LispVal. `return` lets us wrap that up in a Parser action that consumes no input but returns it as the inner value. Thus, the whole `parseString` action will have type `Parser LispVal`. The `$` operator is infix function application: it\'s the same as if we\'d written `return (String x)`, but `$` is right associative and low precedence, letting us eliminate some parentheses. Since `$` is an operator, you can do anything with it that you\'d normally do to a function: pass it around, partially apply it, etc. In this respect, it functions like the Lisp function `apply`. Now let\'s move on to Scheme variables. An atom is a letter or symbol, followed by any number of letters, digits, or symbols: ``` haskell parseAtom :: Parser LispVal parseAtom = do first <- letter <\|> symbol rest <- many (letter <\|> digit <\|> symbol) let atom = first:rest return $ case atom of "#t" -> Bool True "#f" -> Bool False _ -> Atom atom ``` Here, we introduce another Parsec combinator, the choice operator `<\|>`. This tries the first parser, then if it fails, tries the second. If either succeeds, then it returns the value returned by that parser. The first parser must fail before it consumes any input: we\'ll see later how to implement backtracking. Once we\'ve read the first character and the rest of the atom, we need to put them together. The \"`let`\" statement defines a new variable `atom`. We use the list cons operator `:` for this. Instead of `:`, we could have used the concatenation operator `++` like this `[first] ++ rest`; recall that `first` is just a single character, so we convert it into a singleton list by putting brackets around it. Then we use a case expression to determine which `LispVal` to create and return, matching against the literal strings for true and false. The underscore `_` alternative is a readability trick: case blocks continue until a `_` case (or fail any case which also causes the failure of the whole `case` expression), think of `_` as a wildcard. So if the code falls through to the `_` case, it always matches, and returns the value of `atom`. Finally, we create one more parser, for numbers. This shows one more way of dealing with monadic values: ``` haskell parseNumber :: Parser LispVal parseNumber = liftM (Number . read) $ many1 digit ``` It\'s easiest to read this backwards, since both function application (`$`) and function composition (`.`) associate to the right. The parsec combinator many1 matches one or more of its argument, so here we\'re matching one or more digits. We\'d like to construct a number `LispVal` from the resulting string, but we have a few type mismatches. First, we use the built-in function read to convert that string into a number. Then we pass the result to `Number` to get a `LispVal`. The function composition operator `.` creates a function that applies its right argument and then passes the result to the left argument, so we use that to combine the two function applications. Unfortunately, the result of `many1 digit` is actually a `Parser String`, so our combined `Number . read` still can\'t operate on it. We need a way to tell it to just operate on the value inside the monad, giving us back a `Parser LispVal`. The standard function `liftM` does exactly that, so we apply `liftM` to our `Number . read` function, and then apply the result of that to our parser. We also have to import the Monad module up at the top of our program to get access to `liftM`: ``` haskell import Control.Monad ``` This style of programming---relying heavily on function composition, function application, and passing functions to functions---is very common in Haskell code. It often lets you express very complicated algorithms in a single line, breaking down intermediate steps into other functions that can be combined in various ways. Unfortunately, it means that you often have to read Haskell code from right-to-left and keep careful track of the types. We\'ll be seeing many more examples throughout the rest of the tutorial, so hopefully you\'ll get pretty comfortable with it. Let\'s create a parser that accepts either a string, a number, or an atom: ``` haskell parseExpr :: Parser LispVal parseExpr = parseAtom <\|> parseString <\|> parseNumber ``` And edit readExpr so it calls our new parser: ``` haskell readExpr :: String -> String readExpr input = case parse parseExpr "lisp" input of Left err -> "No match: " ++ show err Right _ -> "Found value" ``` Compile and run this code, and you\'ll notice that it accepts any number, string, or symbol, but not other strings: `$ cabal run myProject "\"this is a string\""`\ `Found value`\ `$ cabal run myProject 25`\ `Found value`\ `$ cabal run myProject symbol`\ `Found value`\ `$ cabal run myProject (symbol)`\ `` bash: syntax error near unexpected token `symbol' ``\ `$ cabal run myProject "(symbol)"`\ `No match: "lisp" (line 1, column 1):`\ `unexpected "("`\ `expecting letter, "\"" or digit` ## Recursive Parsers: Adding lists, dotted lists, and quoted datums Next, we add a few more parser actions to our interpreter. Start with the parenthesized lists that make Lisp famous: ``` haskell parseList :: Parser LispVal parseList = liftM List $ sepBy parseExpr spaces ``` This works analogously to `parseNumber`, first parsing a series of expressions separated by whitespace (`sepBy parseExpr spaces`) and then apply the List constructor to it within the Parser monad. Note too that we can pass `parseExpr` to sepBy, even though it\'s an action we wrote ourselves. The dotted-list parser is somewhat more complex, but still uses only concepts that we\'re already familiar with: ``` haskell parseDottedList :: Parser LispVal parseDottedList = do head <- endBy parseExpr spaces tail <- char '.' >> spaces >> parseExpr return $ DottedList head tail ``` Note how we can sequence together a series of Parser actions with `>>` and then use the whole sequence on the right hand side of a do-statement. The expression `char '.' >> spaces` returns a `Parser ()`, then combining that with `parseExpr` gives a `Parser LispVal`, exactly the type we need for the do-block. Next, let\'s add support for the single-quote syntactic sugar of Scheme: ``` haskell parseQuoted :: Parser LispVal parseQuoted = do char '\'' x <- parseExpr return $ List [Atom "quote", x] ``` Most of this is fairly familiar stuff: it reads a single quote character, reads an expression and binds it to `x`, and then returns `(quote x)`, to use Scheme notation. The `Atom` constructor works like an ordinary function: you pass it the String you\'re encapsulating, and it gives you back a LispVal. You can do anything with this LispVal that you normally could, like put it in a list. Finally, edit our definition of parseExpr to include our new parsers: ``` haskell parseExpr :: Parser LispVal parseExpr = parseAtom <\|> parseString <\|> parseNumber <\|> parseQuoted <\|> do char '(' x <- try parseList <\|> parseDottedList char ')' return x ``` This illustrates one last feature of Parsec: backtracking. `parseList` and `parseDottedList` recognize identical strings up to the dot; this breaks the requirement that a choice alternative may not consume any input before failing. The try combinator attempts to run the specified parser, but if it fails, it backs up to the previous state. This lets you use it in a choice alternative without interfering with the other alternative. Compile and run this code: `$ cabal run myProject "(a test)"`\ `Found value`\ `$ cabal run myProject "(a (nested) test)"`\ `Found value`\ `$ cabal run myProject "(a (dotted . list) test)"`\ `Found value`\ `$ cabal run myProject "(a '(quoted (dotted . list)) test)"`\ `Found value`\ `$ cabal run myProject "(a '(imbalanced parens)"`\ `No match: "lisp" (line 1, column 24):`\ `unexpected end of input`\ `expecting space or ")"` Note that by referring to `parseExpr` within our parsers, we can nest them arbitrarily deep. Thus, we get a full Lisp reader with only a few definitions. That\'s the power of recursion.
# Write Yourself a Scheme in 48 Hours/Evaluation, Part 1 ## Beginning the Evaluator Currently, we\'ve just been printing out whether or not we recognize the given program fragment. We\'re about to take the first steps towards a working Scheme interpreter: assigning values to program fragments. We\'ll be starting with baby steps, but fairly soon you\'ll be progressing to working with computations. Let\'s start by telling Haskell how to print out a string representation of the various possible `LispVal`s: ``` haskell showVal :: LispVal -> String showVal (String contents) = "\"" ++ contents ++ "\"" showVal (Atom name) = name showVal (Number contents) = show contents showVal (Bool True) = "#t" showVal (Bool False) = "#f" ``` This is our first real introduction to pattern matching. Pattern matching is a way of destructuring an algebraic data type, selecting a code clause based on its constructor and then binding the components to variables. Any constructor can appear in a pattern; that pattern matches a value if the tag is the same as the value\'s tag and all subpatterns match their corresponding components. Patterns can be nested arbitrarily deep, with matching proceeding in an inside → outside, left → right order. The clauses of a function definition are tried in textual order, until one of the patterns matches. If this is confusing, you\'ll see some examples of deeply-nested patterns when we get further into the evaluator. For now, you only need to know that each clause of the above definition matches one of the constructors of `LispVal`, and the right-hand side tells what to do for a value of that constructor. The `List` and `DottedList` clauses work similarly, but we need to define a helper function `unwordsList` to convert the contained list into a string: ``` haskell showVal (List contents) = "(" ++ unwordsList contents ++ ")" showVal (DottedList head tail) = "(" ++ unwordsList head ++ " . " ++ showVal tail ++ ")" ``` The `unwordsList` function works like the Haskell Prelude\'s `unwords` function, which glues together a list of words with spaces. Since we\'re dealing with a list of `LispVal`s instead of words, we define a function that first converts the `LispVal`s into their string representations and then applies `unwords` to it: ``` haskell unwordsList :: [LispVal] -> String unwordsList = unwords . map showVal ``` Our definition of unwordsList doesn\'t include any arguments. This is an example of point-free style: writing definitions purely in terms of function composition and partial application, without regard to individual values or \"points\". Instead, we define it as the composition of a couple of built-in functions. First, we partially-apply `map` to `showVal`, which creates a function that takes a list of `LispVal`s and returns a list of their string representations. Haskell functions are curried: this means that a function of two arguments, like `map`, is really a function that returns a function of one argument. As a result, if you supply only a single argument, you get back a function of one argument that you can pass around, compose, and apply later. In this case, we compose it with unwords: `map showVal` converts a list of `LispVal`s to a list of their string representations, and then `unwords` joins the result together with spaces. We used the function `show` above. This standard Haskell function lets you convert any type that\'s an instance of the class `Show` into a string. We\'d like to be able to do the same with `LispVal`, so we make it into a member of the class `Show`, defining its `show` method as `showVal`: ``` haskell instance Show LispVal where show = showVal ``` A full treatment of type classes is beyond the scope of this tutorial; you can find more information in other tutorials and the Haskell 2010 report. Let\'s try things out by changing our readExpr function so it returns the string representation of the value actually parsed, instead of just \"Found value\": ``` haskell readExpr input = case parse parseExpr "lisp" input of Left err -> "No match: " ++ show err Right val -> "Found " ++ show val ``` And compile and run... `$ ghc -package parsec -o parser listing4.1.hs`\ `$ ./parser "(1 2 2)"`\ `Found (1 2 2)`\ `$ ./parser "'(1 3 (\"this\" \"one\"))"`\ `Found (quote (1 3 ("this" "one")))` ## Beginnings of an evaluator: Primitives Now, we start with the beginnings of an evaluator. The purpose of an evaluator is to map some \"code\" data type into some \"data\" data type, the result of the evaluation. In Lisp, the data types for both code and data are the same, so our evaluator will return a `LispVal`. Other languages often have more complicated code structures, with a variety of syntactic forms. Evaluating numbers, strings, booleans, and quoted lists is fairly simple: return the datum itself. ``` haskell eval :: LispVal -> LispVal eval val@(String _) = val eval val@(Number _) = val eval val@(Bool _) = val eval (List [Atom "quote", val]) = val ``` This introduces a new type of pattern. The notation `val@(String _)` matches against any `LispVal` that\'s a string and then binds `val` to the whole `LispVal`, and not just the contents of the `String` constructor. The result has type `LispVal` instead of type `String`. The underbar is the \"don\'t care\" variable, matching any value yet not binding it to a variable. It can be used in any pattern, but is especially useful with @-patterns (where you bind the variable to the whole pattern) and with simple constructor-tests where you\'re just interested in the tag of the constructor. The last clause is our first introduction to nested patterns. The type of data contained by `List` is `[LispVal]`, a list of `LispVal`s. We match that against the specific two-element list `[Atom "quote", val]`, a list where the first element is the symbol \"quote\" and the second element can be anything. Then we return that second element. Let\'s integrate `eval` into our existing code. Start by changing `readExpr` back so it returns the expression instead of a string representation of the expression: ``` haskell readExpr :: String -> LispVal readExpr input = case parse parseExpr "lisp" input of Left err -> String $ "No match: " ++ show err Right val -> val ``` And then change our main function to read an expression, evaluate it, convert it to a string, and print it out. Now that we know about the `>>=` monad sequencing operator and the function composition operator, let\'s use them to make this a bit more concise: ``` haskell main :: IO () main = getArgs >>= print . eval . readExpr . head ``` Here, we take the result of the `getArgs` action (a list of strings) and pass it into the composition of: 1. take the first value (`head`); 2. parse it (`readExpr`); 3. evaluate it (`eval`); 4. convert it to a string and print it (`print`). Compile and run the code the normal way: `$ ghc -package parsec -o eval listing4.2.hs`\ `$ ./eval "'atom" `\ `atom`\ `$ ./eval 2`\ `2`\ `$ ./eval "\"a string\""`\ `"a string"`\ `$ ./eval "(+ 2 2)"`\ \ `Fail: listing6.hs:83: Non-exhaustive patterns in function eval` We still can\'t do all that much useful with the program (witness the failed `(+ 2 2)` call), but the basic skeleton is in place. Soon, we\'ll be extending it with some functions to make it useful. ## Adding basic primitives Next, we\'ll improve our Scheme so we can use it as a simple calculator. It\'s still not yet a \"programming language\", but it\'s getting close. Begin by adding a clause to eval to handle function application. Remember that all clauses of a function definition must be placed together and are evaluated in textual order, so this should go after the other eval clauses: ``` haskell eval (List (Atom func : args)) = apply func $ map eval args ``` This is another nested pattern, but this time we match against the cons operator \":\" instead of a literal list. Lists in Haskell are really syntactic sugar for a chain of cons applications and the empty list: `[1, 2, 3, 4] = 1:(2:(3:(4:[])))`. By pattern-matching against cons itself instead of a literal list, we\'re saying \"give me the rest of the list\" instead of \"give me the second element of the list\". For example, if we passed `(+ 2 2)` to eval, `func` would be bound to \"+\" and `args` would be bound to `[Number 2, Number 2]`. The rest of the clause consists of a couple of functions we\'ve seen before and one we haven\'t defined yet. We have to recursively evaluate each argument, so we map `eval` over the args. This is what lets us write compound expressions like `(+ 2 (- 3 1) (* 5 4))`. Then we take the resulting list of evaluated arguments, and pass it and the original function to apply: ``` haskell apply :: String -> [LispVal] -> LispVal apply func args = maybe (Bool False) ($ args) $ lookup func primitives ``` The built-in function `lookup` looks up a key (its first argument) in a list of pairs. However, lookup will fail if no pair in the list contains the matching key. To express this, it returns an instance of the built-in type `Maybe`. We use the function `maybe` to specify what to do in case of either success or failure. If the function isn\'t found, we return a `Bool False` value, equivalent to `#f` (we\'ll add more robust error-checking later). If it is found, we apply it to the arguments using `($ args)`, an operator section of the function application operator. Next, we define the list of primitives that we support: ``` haskell primitives :: [(String, [LispVal] -> LispVal)] primitives = [("+", numericBinop (+)), ("-", numericBinop (-)), ("", numericBinop ()), ("/", numericBinop div), ("mod", numericBinop mod), ("quotient", numericBinop quot), ("remainder", numericBinop rem)] ``` Look at the type of `primitives`. It is a list of pairs, just like `lookup` expects, but the values of the pairs are functions from `[LispVal]` to `LispVal`. In Haskell, you can easily store functions in other data structures, though the functions must all have the same type. Also, the functions that we store are themselves the result of a function, `numericBinop`, which we haven\'t defined yet. This takes a primitive Haskell function (often an operator section) and wraps it with code to unpack an argument list, apply the function to it, and wrap the result up in our `Number` constructor. ``` haskell numericBinop :: (Integer -> Integer -> Integer) -> [LispVal] -> LispVal numericBinop op params = Number $ foldl1 op $ map unpackNum params unpackNum :: LispVal -> Integer unpackNum (Number n) = n unpackNum (String n) = let parsed = reads n :: [(Integer, String)] in if null parsed then 0 else fst $ parsed !! 0 unpackNum (List [n]) = unpackNum n unpackNum _ = 0 ``` As with R5RS Scheme, we don\'t limit ourselves to only two arguments. Our numeric operations can work on a list of any length, so `(+ 2 3 4) = 2 + 3 + 4`, and `(- 15 5 3 2) = 15 - 5 - 3 - 2`. We use the built-in function `foldl1` to do this. It essentially changes every cons operator in the list to the binary function we supply, `op`. Unlike R5RS Scheme, we\'re implementing a form of weak typing. That means that if a value can be interpreted as a number (like the string \"2\"), we\'ll use it as one, even if it\'s tagged as a string. We do this by adding a couple extra clauses to `unpackNum`. If we\'re unpacking a string, attempt to parse it with Haskell\'s built-in `reads` function, which returns a list of pairs of (parsed value, remaining string). For lists, we pattern-match against the one-element list and try to unpack that. Anything else falls through to the next case. If we can\'t parse the number, for any reason, we\'ll return 0 for now. We\'ll fix this shortly so that it signals an error. Compile and run this the normal way. Note how we get nested expressions \"for free\" because we call eval on each of the arguments of a function: `$ ghc -package parsec -o eval listing7.hs`\ `$ ./eval "(+ 2 2)"`\ `4`\ `$ ./eval "(+ 2 (-4 1))"`\ `2`\ `$ ./eval "(+ 2 (- 4 1))"`\ `5`\ `$ ./eval "(- (+ 4 6 3) 3 5 2)"`\ `3`
# Write Yourself a Scheme in 48 Hours/Error Checking and Exceptions Currently, there are a variety of places within the code where we either ignore errors or silently assign \"default\" values like `#f` or 0 that make no sense. Some languages -- like Perl and PHP -- get along fine with this approach. However, it often means that errors pass silently throughout the program until they become big problems, which means rather inconvenient debugging sessions for the programmer. We\'d like to signal errors as soon as they happen and immediately break out of execution. First, we need to import `Control.Monad.Except` to get access to Haskell\'s built-in error functions: ``` haskell import Control.Monad.Except ``` On Debian based systems this needs `libghc6-mtl-dev` installed. Then, we should define a data type to represent an error: ``` haskell data LispError = NumArgs Integer [LispVal] \| TypeMismatch String LispVal \| Parser ParseError \| BadSpecialForm String LispVal \| NotFunction String String \| UnboundVar String String \| Default String ``` This is a few more constructors than we need at the moment, but we might as well foresee all the other things that can go wrong in the interpreter later. Next, we define how to print out the various types of errors and make `LispError` an instance of `Show`: ``` haskell showError :: LispError -> String showError (UnboundVar message varname) = message ++ ": " ++ varname showError (BadSpecialForm message form) = message ++ ": " ++ show form showError (NotFunction message func) = message ++ ": " ++ show func showError (NumArgs expected found) = "Expected " ++ show expected ++ " args; found values " ++ unwordsList found showError (TypeMismatch expected found) = "Invalid type: expected " ++ expected ++ ", found " ++ show found showError (Parser parseErr) = "Parse error at " ++ show parseErr instance Show LispError where show = showError ``` Then we define a type to represent functions that may throw a `LispError` or return a value. Remember how `parse` used an `Either` data type to represent exceptions? We take the same approach here: ``` haskell type ThrowsError = Either LispError ``` Type constructors are curried just like functions, and can also be partially applied. A full type would be `Either LispError Integer` or `Either LispError LispVal`, but we want to say `ThrowsError LispVal` and so on. We only partially apply `Either` to `LispError`, creating a type constructor `ThrowsError` that we can use on any data type. `Either` is yet another instance of a monad. In this case, the \"extra information\" being passed between `Either` actions is whether or not an error occurred. Bind applies its function if the `Either` action holds a normal value, or passes an error straight through without computation. This is how exceptions work in other languages, but because Haskell is lazily-evaluated, there\'s no need for a separate control-flow construct. If bind determines that a value is already an error, the function is never called. The `Control.Monad.Except` library automatically gives the `Either` monad two other functions besides the standard monadic ones: 1. `throwError`, which takes an `Error` value and lifts it into the `Left` (error) constructor of an `Either` 2. `catchError`, which takes an `Either` action and a function that turns an error into another `Either` action. If the action represents an error, it applies the function, which you can use to, e.g. turn the error value into a normal one via `return` or re-throw as a different error. In our program, we\'ll be converting all of our errors to their string representations and returning that as a normal value. Let\'s create a helper function to do that for us: ``` haskell trapError action = catchError action (return . show) ``` The result of calling `trapError` is another `Either` action which will always have valid (`Right`) data. We still need to extract that data from the `Either` monad so it can be passed around to other functions: ``` haskell extractValue :: ThrowsError a -> a extractValue (Right val) = val ``` We purposely leave `extractValue` undefined for a `Left` constructor, because that represents a programmer error. We intend to use `extractValue` only after a `catchError`, so it\'s better to fail fast than to inject bad values into the rest of the program. Now that we have all the basic infrastructure, it\'s time to start using our error-handling functions. Remember how our parser had previously just returned a string saying \"No match\" on an error? Let\'s change it so that it wraps and throws the original `ParseError`: ``` haskell readExpr :: String -> ThrowsError LispVal readExpr input = case parse parseExpr "lisp" input of Left err -> throwError $ Parser err Right val -> return val ``` Here, we first wrap the original `ParseError` with the `LispError` constructor `Parser`, and then use the built-in function `throwError` to return that in our `ThrowsError` monad. Since `readExpr` now returns a monadic value, we also need to wrap the other case in a return function. Next, we change the type signature of `eval` to return a monadic value, adjust the return values accordingly, and add a clause to throw an error if we encounter a pattern that we don\'t recognize: ``` haskell eval :: LispVal -> ThrowsError LispVal eval val@(String _) = return val eval val@(Number _) = return val eval val@(Bool _) = return val eval (List [Atom "quote", val]) = return val eval (List (Atom func : args)) = mapM eval args >>= apply func eval badForm = throwError $ BadSpecialForm "Unrecognized special form" badForm ``` Since the function application clause calls `eval` (which now returns a monadic value) recursively, we need to change that clause. First, we had to change `map` to `mapM`, which maps a monadic function over a list of values, sequences the resulting actions together with bind, and then returns a list of the inner results. Inside the `Error` monad, this sequencing performs all computations sequentially but throws an error value if any one of them fails -- giving you `Right [results]` on success, or `Left error` on failure. Then, we used the monadic \"bind\" operation to pass the result into the partially applied \"apply func\", again returning an error if either operation failed. Next, we change `apply` itself so that it throws an error if it doesn\'t recognize the function: ``` haskell apply :: String -> [LispVal] -> ThrowsError LispVal apply func args = maybe (throwError $ NotFunction "Unrecognized primitive function args" func) ($ args) (lookup func primitives) ``` We didn\'t add a return statement to the function application `($ args)`. We\'re about to change the type of our primitives, so that the function returned from the lookup itself returns a `ThrowsError` action: ``` haskell primitives :: [(String, [LispVal] -> ThrowsError LispVal)] ``` And, of course, we need to change the numericBinop function that implements these primitives so it throws an error if there\'s only one argument: ``` haskell numericBinop :: (Integer -> Integer -> Integer) -> [LispVal] -> ThrowsError LispVal numericBinop op [] = throwError $ NumArgs 2 [] numericBinop op singleVal@[_] = throwError $ NumArgs 2 singleVal numericBinop op params = mapM unpackNum params >>= return . Number . foldl1 op ``` We use an at-pattern to capture the single-value case because we want to include the actual value passed in for error-reporting purposes. Here, we\'re looking for a list of exactly one element, and we don\'t care what that element is. We also need to use `mapM` to sequence the results of `unpackNum`, because each individual call to `unpackNum` may fail with a `TypeMismatch`: ``` haskell unpackNum :: LispVal -> ThrowsError Integer unpackNum (Number n) = return n unpackNum (String n) = let parsed = reads n in if null parsed then throwError $ TypeMismatch "number" $ String n else return $ fst $ parsed !! 0 unpackNum (List [n]) = unpackNum n unpackNum notNum = throwError $ TypeMismatch "number" notNum ``` Finally, we need to change our main function to use this whole big error monad. This can get a little complicated, because now we\'re dealing with two monads (`Either` (for errors) and `IO`). As a result, we go back to do-notation, because it\'s nearly impossible to use point-free style when the result of one monad is nested inside another: ``` haskell main :: IO () main = do args <- getArgs evaled <- return $ liftM show $ readExpr (args !! 0) >>= eval putStrLn $ extractValue $ trapError evaled ``` Here\'s what this new function is doing: 1. `args` is the list of command-line arguments. 2. `evaled` is the result of: 1. taking first argument (`args !! 0`); 2. parsing it (`readExpr`); 3. passing it to `eval` (`>>= eval`; the bind operation has higher precedence than `$`); 4. calling `show` on it within the `Error` monad. (Note also that the whole action has type `IO (Either LispError String)`, giving `evaled` type `Either LispError String`. It has to be, because our `trapError` function can only convert errors to `String`s, and that type must match the type of normal values.) 3. Caught is the result of: 1. calling `trapError` on `evaled`, converting errors to their string representation; 2. calling `extractValue` to get a `String` out of this `Either LispError String` action; 3. printing the results through `putStrLn`. Compile and run the new code, and try throwing it a couple errors: `$ ghc -package parsec -o errorcheck [../code/listing5.hs listing5.hs]`\ `$ ./errorcheck "(+ 2 \"two\")"`\ `Invalid type: expected number, found "two"`\ `$ ./errorcheck "(+ 2)"`\ `Expected 2 args; found values 2`\ `$ ./errorcheck "(what? 2)"`\ `Unrecognized primitive function args: "what?"` Some readers have reported that you need to add a `--make` flag to build this example, and presumably all further listings. This tells GHC to build a complete executable, searching out all dependencies listed in the import statements. The command above works on my system, but if it fails on yours, give `--make` a try.
# Write Yourself a Scheme in 48 Hours/Evaluation, Part 2 ## Additional Primitives: Partial Application Now that we can deal with type errors, bad arguments, and so on, we\'ll flesh out our primitive list so that it does something more than calculate. We\'ll add boolean operators, conditionals, and some basic string operations. Start by adding the following into the list of primitives: ``` haskell ("=", numBoolBinop (==)), ("<", numBoolBinop (<)), (">", numBoolBinop (>)), ("/=", numBoolBinop (/=)), (">=", numBoolBinop (>=)), ("<=", numBoolBinop (<=)), ("&&", boolBoolBinop (&&)), ("\|\|", boolBoolBinop (\|\|)), ("string=?", strBoolBinop (==)), ("string<?", strBoolBinop (<)), ("string>?", strBoolBinop (>)), ("string<=?", strBoolBinop (<=)), ("string>=?", strBoolBinop (>=)), ``` These depend on helper functions that we haven\'t written yet: `numBoolBinop`, `boolBoolBinop` and `strBoolBinop`. Instead of taking a variable number of arguments and returning an integer, these both take exactly two arguments and return a boolean. They differ from each other only in the type of argument they expect, so let\'s factor the duplication into a generic `boolBinop` function that\'s parametrized by the unpacker function it applies to its arguments: ``` haskell boolBinop :: (LispVal -> ThrowsError a) -> (a -> a -> Bool) -> [LispVal] -> ThrowsError LispVal boolBinop unpacker op args = if length args /= 2 then throwError $ NumArgs 2 args else do left <- unpacker $ args !! 0 right <- unpacker $ args !! 1 return $ Bool $ left `op` right ``` Because each argument may throw a type mismatch, we have to unpack them sequentially, in a do-block (for the `Error` monad). We then apply the operation to the two arguments and wrap the result in the `Bool` constructor. Any function can be turned into an infix operator by wrapping it in backticks (`` `op` ``). Also, take a look at the type signature. `boolBinop` takes two functions as its first two arguments: the first is used to unpack the arguments from `LispVal`s to native Haskell types, and the second is the actual operation to perform. By parameterizing different parts of the behavior, you make the function more reusable. Now we define three functions that specialize `boolBinop` with different unpackers: ``` haskell numBoolBinop = boolBinop unpackNum strBoolBinop = boolBinop unpackStr boolBoolBinop = boolBinop unpackBool ``` We haven\'t told Haskell how to unpack strings from `LispVal`s yet. This works similarly to `unpackNum`, pattern matching against the value and either returning it or throwing an error. Again, if passed a primitive value that could be interpreted as a string (such as a number or boolean), it will silently convert it to the string representation. ``` haskell unpackStr :: LispVal -> ThrowsError String unpackStr (String s) = return s unpackStr (Number s) = return $ show s unpackStr (Bool s) = return $ show s unpackStr notString = throwError $ TypeMismatch "string" notString ``` And we use similar code to unpack booleans: ``` haskell unpackBool :: LispVal -> ThrowsError Bool unpackBool (Bool b) = return b unpackBool notBool = throwError $ TypeMismatch "boolean" notBool ``` Let\'s compile and test this to make sure it\'s working, before we proceed to the next feature: `$ ghc -package parsec -o simple_parser [../code/listing6.1.hs listing6.1.hs]`\ `$ ./simple_parser "(< 2 3)"`\ `#t`\ `$ ./simple_parser "(> 2 3)"`\ `#f`\ `$ ./simple_parser "(>= 3 3)"`\ `#t`\ `$ ./simple_parser "(string=? \"test\" \"test\")"`\ `#t`\ `$ ./simple_parser "(string<? \"abc\" \"bba\")"`\ `#t` ## Conditionals: Pattern Matching 2 Now, we\'ll proceed to adding an if-clause to our evaluator. As with standard Scheme, our evaluator considers `#f` to be false and any other value to be true: ``` haskell eval (List [Atom "if", pred, conseq, alt]) = do result <- eval pred case result of Bool False -> eval alt otherwise -> eval conseq ``` As the function definitions are evaluated in order, be sure to place this one above `eval (List (Atom func : args)) = mapM eval args >>= apply func` or it will throw a `Unrecognized primitive function args: "if"` error. This is another example of nested pattern-matching. Here, we\'re looking for a 4-element list. The first element must be the atom `if`. The others can be any Scheme forms. We take the first element, evaluate, and if it\'s false, evaluate the alternative. Otherwise, we evaluate the consequent. Compile and run this, and you\'ll be able to play around with conditionals: `$ ghc -package parsec -o simple_parser [../code/listing6.2.hs listing6.2.hs]`\ `$ ./simple_parser "(if (> 2 3) \"no\" \"yes\")"`\ `"yes"`\ `$ ./simple_parser "(if (= 3 3) (+ 2 3 (- 5 1)) \"unequal\")"`\ `9` ## List Primitives: `car`, `cdr`, and `cons` For good measure, let\'s also add in the basic list-handling primitives. Because we\'ve chosen to represent our lists as Haskell algebraic data types instead of pairs, these are somewhat more complicated than their definitions in many Lisps. It\'s easiest to think of them in terms of their effect on printed S-expressions: 1. `(car '(a b c)) = a` 2. `(car '(a)) = a` 3. `(car '(a b . c)) = a` 4. `(car 'a) = error` -- not a list 5. `(car 'a 'b) = error` -- `car` only takes one argument We can translate these fairly straightforwardly into pattern clauses, recalling that `(x : xs)` divides a list into the first element and the rest: ``` haskell car :: [LispVal] -> ThrowsError LispVal car [List (x : xs)] = return x car [DottedList (x : xs) _] = return x car [badArg] = throwError $ TypeMismatch "pair" badArg car badArgList = throwError $ NumArgs 1 badArgList ``` Let\'s do the same with cdr: 1. `(cdr '(a b c)) = (b c)` 2. `(cdr '(a b)) = (b)` 3. `(cdr '(a)) = NIL` 4. `(cdr '(a . b)) = b` 5. `(cdr '(a b . c)) = (b . c)` 6. `(cdr 'a) = error` -- not a list 7. `(cdr 'a 'b) = error` -- too many arguments We can represent the first three cases with a single clause. Our parser represents `'()` as `List []`, and when you pattern-match `(x : xs)` against `[x]`, `xs` is bound to `[]`. The other ones translate to separate clauses: ``` haskell cdr :: [LispVal] -> ThrowsError LispVal cdr [List (x : xs)] = return $ List xs cdr [DottedList [_] x] = return x cdr [DottedList (_ : xs) x] = return $ DottedList xs x cdr [badArg] = throwError $ TypeMismatch "pair" badArg cdr badArgList = throwError $ NumArgs 1 badArgList ``` `cons` is a little tricky, enough that we should go through each clause case-by-case. If you cons together anything with `Nil`, you end up with a one-item list, the `Nil` serving as a terminator: ``` haskell cons :: [LispVal] -> ThrowsError LispVal cons [x1, List []] = return $ List [x1] ``` If you `cons` together anything and a list, it\'s like tacking that anything onto the front of the list: ``` haskell cons [x, List xs] = return $ List $ x : xs ``` However, if the list is a `DottedList`, then it should stay a `DottedList`, taking into account the improper tail: ``` haskell cons [x, DottedList xs xlast] = return $ DottedList (x : xs) xlast ``` If you `cons` together two non-lists, or put a list in front, you get a `DottedList`. This is because such a `cons` cell isn\'t terminated by the normal `Nil` that most lists are. ``` haskell cons [x1, x2] = return $ DottedList [x1] x2 ``` Finally, attempting to `cons` together more or less than two arguments is an error: ``` haskell cons badArgList = throwError $ NumArgs 2 badArgList ``` Our last step is to implement `eqv?`. Scheme offers three levels of equivalence predicates: `eq?`, `eqv?`, and `equal?`. For our purposes, `eq?` and `eqv?` are basically the same: they recognize two items as the same if they print the same, and are fairly slow. So we can write one function for both of them and register it under `eq?` and `eqv?`. ``` haskell eqv :: [LispVal] -> ThrowsError LispVal eqv [(Bool arg1), (Bool arg2)] = return $ Bool $ arg1 == arg2 eqv [(Number arg1), (Number arg2)] = return $ Bool $ arg1 == arg2 eqv [(String arg1), (String arg2)] = return $ Bool $ arg1 == arg2 eqv [(Atom arg1), (Atom arg2)] = return $ Bool $ arg1 == arg2 eqv [(DottedList xs x), (DottedList ys y)] = eqv [List $ xs ++ [x], List $ ys ++ [y]] eqv [(List arg1), (List arg2)] = return $ Bool $ (length arg1 == length arg2) && (all eqvPair $ zip arg1 arg2) where eqvPair (x1, x2) = case eqv [x1, x2] of Left err -> False Right (Bool val) -> val eqv [_, _] = return $ Bool False eqv badArgList = throwError $ NumArgs 2 badArgList ``` Most of these clauses are self-explanatory, the exception being the one for two `Lists`. This, after checking to make sure the lists are the same length, `zip`s the two lists of pairs, and then uses the function `all` to return `False` if `eqvPair` returns `False` on any of the pairs. `eqvPair` is an example of a local definition: it is defined using the `where` keyword, just like a normal function, but is available only within that particular clause of `eqv`. Since we know that `eqv` only throws an error if the number of arguments is not 2, the line `Left err -> False` will never be executed at the moment. ## `equal?` and Weak Typing: Heterogenous Lists Since we introduced weak typing above, we\'d also like to introduce an `equal?` function that ignores differences in the type tags and only tests if two values can be interpreted the same. For example, `(eqv? 2 "2") = #f`, yet we\'d like `(equal? 2 "2") = #t`. Basically, we want to try all of our unpack functions, and if any of them result in Haskell values that are equal, return `True`. The obvious way to approach this is to store the unpacking functions in a list and use `mapM` to execute them in turn. Unfortunately, this doesn\'t work, because standard Haskell only lets you put objects in a list if they\'re the same type. The various unpacker functions return different types, so you can\'t store them in the same list. We\'ll get around this by using a GHC extension -- Existential Types -- that lets us create a heterogenous list, subject to typeclass constraints. Extensions are fairly common in the Haskell world: they\'re basically necessary to create any reasonably large program, and they\'re often compatible between implementations (existential types work in both Hugs and GHC and are a candidate for standardization). Note you need to use a special compiler flag for this: `-fglasgow-exts` as mentioned below; the newer `-XExistentialQuantification`; or add the pragma `{-# LANGUAGE ExistentialQuantification #-}` to the beginning of your code (In general, the compiler flag `-Xfoo` can be replaced by the pragma `{-# LANGUAGE foo #-}` inside the source file). The first thing we need to do is define a data type that can hold any function from a `LispVal -> something`, provided that that `something` supports equality: ``` haskell data Unpacker = forall a. Eq a => AnyUnpacker (LispVal -> ThrowsError a) ``` This is like any normal algebraic datatype, except for the type constraint. It says, \"For any type that is an instance of `Eq`, you can define an `Unpacker` that takes a function from `LispVal` to that type, and may throw an error\". We\'ll have to wrap our functions with the `AnyUnpacker` constructor, but then we can create a list of `Unpacker`s that does just what we want it. Rather than jump straight to the `equal?` function, let\'s first define a helper function that takes an `Unpacker` and then determines if two `LispVal`s are equal when it unpacks them: ``` haskell unpackEquals :: LispVal -> LispVal -> Unpacker -> ThrowsError Bool unpackEquals arg1 arg2 (AnyUnpacker unpacker) = do unpacked1 <- unpacker arg1 unpacked2 <- unpacker arg2 return $ unpacked1 == unpacked2 `catchError` (const $ return False) ``` After pattern-matching to retrieve the actual function, we enter a do-block for the `ThrowsError` monad. This retrieves the Haskell values of the two `LispVal`s, and then tests whether they\'re equal. If there is an error anywhere within the two unpackers, it returns `False`, using the `const` function because `catchError` expects a function to apply to the error value. Finally, we can define `equal?` in terms of these helpers: ``` haskell equal :: [LispVal] -> ThrowsError LispVal equal [arg1, arg2] = do primitiveEquals <- liftM or $ mapM (unpackEquals arg1 arg2) [AnyUnpacker unpackNum, AnyUnpacker unpackStr, AnyUnpacker unpackBool] eqvEquals <- eqv [arg1, arg2] return $ Bool $ (primitiveEquals \|\| let (Bool x) = eqvEquals in x) equal badArgList = throwError $ NumArgs 2 badArgList ``` The first action makes a heterogenous list of `[unpackNum, unpackStr, unpackBool]`, and then maps the partially applied `(unpackEquals arg1 arg2)` over it. This gives a list of booleans, so we use the Prelude function `or` to return true if any single one of them is true. The second action tests the two arguments with `eqv?`. Since we want `equal?` to be looser than `eqv?`, it should return true whenever `eqv?` does so. This also lets us avoid handling cases like the list or dotted-list (though this introduces a bug; see exercise #2 in this section). Finally, `equal?` `or`s both of these values together and wraps the result in the `Bool` constructor, returning a `LispVal`. The `let (Bool x) = eqvEquals in x` is a quick way of extracting a value from an algebraic type: it pattern matches `Bool x` against the `eqvEquals` value, and then returns `x`. The result of a let-expression is the expression following the keyword `in`. To use these functions, insert them into our primitives list: ``` haskell ("car", car), ("cdr", cdr), ("cons", cons), ("eq?", eqv), ("eqv?", eqv), ("equal?", equal)] ``` To compile this code, you need to enable GHC extensions with `-fglasgow-exts`: `$ ghc -package parsec -fglasgow-exts -o parser [../code/listing6.4.hs listing6.4.hs]`\ `$ ./parser "(cdr '(a simple test))"`\ `(simple test)`\ `$ ./parser "(car (cdr '(a simple test)))"`\ `simple`\ `$ ./parser "(car '((this is) a test))"`\ `(this is)`\ `$ ./parser "(cons '(this is) 'test)"`\ `((this is) . test)`\ `$ ./parser "(cons '(this is) '())"`\ `((this is))`\ `$ ./parser "(eqv? 1 3)"`\ `#f`\ `$ ./parser "(eqv? 3 3)"`\ `#t`\ `$ ./parser "(eqv? 'atom 'atom)"`\ `#t`
# Write Yourself a Scheme in 48 Hours/Building a REPL So far, we\'ve been content to evaluate single expressions from the command line, printing the result and exiting afterwards. This is fine for a calculator, but isn\'t what most people think of as \"programming\". We\'d like to be able to define new functions and variables, and refer to them later. But before we can do this, we need to build a system that can execute multiple statements without exiting the program. Instead of executing a whole program at once, we\'re going to build a read-eval-print loop. This reads in expressions from the console one at a time and executes them interactively, printing the result after each expression. Later expressions can reference variables set by earlier ones (or will be able to, after the next section), letting you build up libraries of functions. First, we need to import some additional IO functions. Add the following to the top of the program: ``` haskell import System.IO ``` Next, we define a couple of helper functions to simplify some of our IO tasks. We\'ll want a function that prints out a string and immediately flushes the stream; otherwise, output might sit in output buffers and the user will never see prompts or results. ``` haskell flushStr :: String -> IO () flushStr str = putStr str >> hFlush stdout ``` Then, we create a function that prints out a prompt and reads in a line of input: ``` haskell readPrompt :: String -> IO String readPrompt prompt = flushStr prompt >> getLine ``` Pull the code to parse and evaluate a string and trap the errors out of main into its own function: ``` haskell evalString :: String -> IO String evalString expr = return $ extractValue $ trapError (liftM show $ readExpr expr >>= eval) ``` And write a function that evaluates a string and prints the result: ``` haskell evalAndPrint :: String -> IO () evalAndPrint expr = evalString expr >>= putStrLn ``` Now it\'s time to tie it all together. We want to read input, perform a function, and print the output, all in an infinite loop. The built-in function `interact` almost does what we want, but doesn\'t loop. If we used the combination `sequence . repeat . interact`, we\'d get an infinite loop, but we wouldn\'t be able to break out of it. So we need to roll our own loop: ``` haskell until_ :: Monad m => (a -> Bool) -> m a -> (a -> m ()) -> m () until_ pred prompt action = do result <- prompt if pred result then return () else action result >> until_ pred prompt action ``` The underscore after the name is a typical naming convention in Haskell for monadic functions that repeat but do not return a value. `until_` takes a predicate that signals when to stop, an action to perform before the test, and a function-returning-an-action to do to the input. Each of the latter two is generalized over any monad, not just `IO`. That\'s why we write their types using the type variable `m`, and include the type constraint `Monad m =>`. Note also that we can write recursive actions just as we write recursive functions. Now that we have all the machinery in place, we can write our REPL easily: ``` haskell runRepl :: IO () runRepl = until_ (== "quit") (readPrompt "Lisp>>> ") evalAndPrint ``` And change our main function so it either executes a single expression, or enters the REPL and continues evaluating expressions until we type `quit`: ``` haskell main :: IO () main = do args <- getArgs case length args of 0 -> runRepl 1 -> evalAndPrint $ args !! 0 _ -> putStrLn "Program takes only 0 or 1 argument" ``` Compile and run the program, and try it out: `$ ghc -package parsec -fglasgow-exts -o lisp [../code/listing7.hs listing7.hs]`\ `$ ./lisp`\ `Lisp>>> (+ 2 3)`\ `5`\ `Lisp>>> (cons this '())`\ `Unrecognized special form: this`\ `Lisp>>> (cons 2 3)`\ `(2 . 3)`\ `Lisp>>> (cons 'this '())`\ `(this)`\ `Lisp>>> quit`\ `$`
# Write Yourself a Scheme in 48 Hours/Adding Variables and Assignment Finally, we get to the good stuff: variables. A variable lets us save the result of an expression and refer to it later. In Scheme, a variable can also be reset to new values, so that its value changes as the program executes. This presents a complication for Haskell, because the execution model is built upon functions that return values, but never change them. Nevertheless, there are several ways to simulate state in Haskell, all involving monads. The simplest is probably the state monad, which lets you hide arbitrary state within the monad and pass it around behind the scenes. You specify the state type as a parameter to the monad (e.g. if a function returns an integer but modifies a list of string pairs, it would have type `State [(String, String)] Integer`), and access it via the get and put functions, usually within a do-block. You\'d specify the initial state via the `runState myStateAction initialList`, which returns a pair containing the return value and the final state. Unfortunately, the state monad doesn\'t work well for us, because the type of data we need to store is fairly complex. For a simple top-level environment, we could get away with `[(String, LispVal)]`, storing mappings from variable names to values. However, when we start dealing with function calls, these mappings become a stack of nested environments, arbitrarily deep. And when we add closures, environments might get saved in an arbitrary Function value, and passed around throughout the program. In fact, they might be saved in a variable and passed out of the `runState` monad entirely, something we\'re not allowed to do. Instead, we use a feature called state threads, letting Haskell manage the aggregate state for us. This lets us treat mutable variables as we would in any other programming language, using functions to get or set variables. There are two flavors of state threads: the `ST` monad creates a stateful computation that can be executed as a unit, without the state escaping to the rest of the program. The `IORef` module lets you use stateful variables within the IO monad. Since our state has to be interleaved with IO anyway (it persists between lines in the REPL, and we will eventually have IO functions within the language itself), we\'ll be using `IORef`s. We can start out by importing `Data.IORef` and defining a type for our environments: ``` haskell import Data.IORef type Env = IORef [(String, IORef LispVal)] ``` This declares an `Env` as an `IORef` holding a list that maps `String`s to mutable `LispVal`s. We need `IORef`s for both the list itself and for individual values because there are two ways that the program can mutate the environment. It might use `set!` to change the value of an individual variable, a change visible to any function that shares that environment (Scheme allows nested scopes, so a variable in an outer scope is visible to all inner scopes). Or it might use `define` to add a new variable, which should be visible on all subsequent statements. Since `IORef`s can only be used within the IO monad, we\'ll want a helper action to create an empty environment. We can\'t just use the empty list `[]` because all accesses to `IORef`s must be sequenced, and so the type of our null environment is `IO Env` instead of just plain `Env`: ``` haskell nullEnv :: IO Env nullEnv = newIORef [] ``` From here, things get a bit more complicated, because we\'ll be simultaneously dealing with two monads. Remember, we also need an `Error` monad to handle things like unbound variables. The parts that need IO functionality and the parts that may throw exceptions are interleaved, so we can\'t just catch all the exceptions and return only normal values to the IO monad. Haskell provides a mechanism known as monad transformers that lets you combine the functionality of multiple monads. We\'ll be using one of these, `ExceptT`, which lets us layer error-handling functionality on top of the IO monad. Our first step is to create a type synonym for our combined monad: ``` haskell type IOThrowsError = ExceptT LispError IO ``` Like `ThrowsError`, `IOThrowsError` is really a type constructor: we\'ve left off the last argument, the return type of the function. However, `ExceptT` takes one more argument than plain old `Either`: we have to specify the type of monad that we\'re layering our error-handling functionality over. We\'ve created a monad that may contain IO actions that throw a `LispError`. We have a mix of `ThrowsError` and `IOThrowsError` functions, but actions of different types cannot be contained within the same do-block, even if they provide essentially the same functionality. Haskell already provides a mechanism, lifting, to bring values of the lower type (`IO`) into the combined monad. Unfortunately, there\'s no similar support to bring a value of the untransformed upper type into the combined monad, so we need to write it ourselves: ``` haskell liftThrows :: ThrowsError a -> IOThrowsError a liftThrows (Left err) = throwError err liftThrows (Right val) = return val ``` This destructures the `Either` type and either re-throws the error type or returns the ordinary value. Methods in typeclasses resolve based on the type of the expression, so `throwError` and `return` (members of `MonadError` and `Monad`, respectively) take on their `IOThrowsError` definitions. Incidentally, the type signature provided here is not fully general: if we\'d left it off, the compiler would have inferred `liftThrows :: (MonadError m a) => Either e a -> m a`. We\'ll also want a helper function to run the whole top-level `IOThrowsError` action, returning an IO action. We can\'t escape from the IO monad, because a function that performs IO has an effect on the outside world, and you don\'t want that in a lazily-evaluated pure function. But you can run the error computation and catch the errors. ``` haskell runIOThrows :: IOThrowsError String -> IO String runIOThrows action = runExceptT (trapError action) >>= return . extractValue ``` This uses our previously-defined `trapError` function to take any error values and convert them to their string representations, then runs the whole computation via `runExceptT`. The result is passed into `extractValue` and returned as a value in the IO monad. Now we\'re ready to return to environment handling. We\'ll start with a function to determine if a given variable is already bound in the environment, necessary for proper handling of `define`: ``` haskell isBound :: Env -> String -> IO Bool isBound envRef var = readIORef envRef >>= return . maybe False (const True) . lookup var ``` This first extracts the actual environment value from its `IORef` via `readIORef`. Then we pass it to lookup to search for the particular variable we\'re interested in. lookup returns a `Maybe` value, so we return `False` if that value was `Nothing` and `True` otherwise (we need to use the `const` function because `maybe` expects a function to perform on the result and not just a value). Finally, we use return to lift that value into the IO monad. Since we\'re just interested in a true/false value, we don\'t need to deal with the actual `IORef` that lookup returns. Next, we\'ll want to define a function to retrieve the current value of a variable: ``` haskell getVar :: Env -> String -> IOThrowsError LispVal getVar envRef var = do env <- liftIO $ readIORef envRef maybe (throwError $ UnboundVar "Getting an unbound variable" var) (liftIO . readIORef) (lookup var env) ``` Like the previous function, this begins by retrieving the actual environment from the `IORef`. However, `getVar` uses the `IOThrowsError` monad, because it also needs to do some error handling. As a result, we need to use the `liftIO` function to lift the `readIORef` action into the combined monad. Similarly, when we return the value, we use `liftIO . readIORef` to generate an `IOThrowsError` action that reads the returned `IORef`. We don\'t need to use `liftIO` to throw an error, however, because `throwError` is a defined for the `MonadError` typeclass, of which `ExceptT` is an instance. Now we create a function to set values: ``` haskell setVar :: Env -> String -> LispVal -> IOThrowsError LispVal setVar envRef var value = do env <- liftIO $ readIORef envRef maybe (throwError $ UnboundVar "Setting an unbound variable" var) (liftIO . (flip writeIORef value)) (lookup var env) return value ``` Again, we first read the environment out of its `IORef` and run a lookup on it. This time, however, we want to change the variable instead of just reading it. The `writeIORef` action provides a means for this, but takes its arguments in the wrong order (ref -\> value instead of value -\> ref). So we use the built-in function `flip` to switch the arguments of `writeIORef` around, and then pass it the value. Finally, we return the value we just set, for convenience. We\'ll want a function to handle the special behavior of `define`, which sets a variable if already bound or creates a new one if not. Since we\'ve already defined a function to set values, we can use it in the former case: ``` haskell defineVar :: Env -> String -> LispVal -> IOThrowsError LispVal defineVar envRef var value = do alreadyDefined <- liftIO $ isBound envRef var if alreadyDefined then setVar envRef var value >> return value else liftIO $ do valueRef <- newIORef value env <- readIORef envRef writeIORef envRef ((var, valueRef) : env) return value ``` It\'s the latter case that\'s interesting, where the variable is unbound. We create an IO action (via do-notation) that creates a new `IORef` to hold the new variable, reads the current value of the environment, then writes a new list back to that variable consisting of the new (key, variable) pair added to the front of the list. Then we lift that whole do-block into the `IOThrowsError` monad with `liftIO`. There\'s one more useful environment function: being able to bind a whole bunch of variables at once, as happens when a function is invoked. We might as well build that functionality now, though we won\'t be using it until the next section: ``` haskell bindVars :: Env -> [(String, LispVal)] -> IO Env bindVars envRef bindings = readIORef envRef >>= extendEnv bindings >>= newIORef where extendEnv bindings env = liftM (++ env) (mapM addBinding bindings) addBinding (var, value) = do ref <- newIORef value return (var, ref) ``` This is perhaps more complicated than the other functions, since it uses a monadic pipeline (rather than do-notation) and a pair of helper functions to do the work. It\'s best to start with the helper functions. addBinding takes a variable name and value, creates an `IORef` to hold the new variable, and then returns the name--value pair. `extendEnv` calls `addBinding` on each member of bindings (`mapM`) to create a list of `(String, IORef LispVal)` pairs, and then appends the current environment to the end of that `(++ env)`. Finally, the whole function wires these functions up in a pipeline, starting by reading the existing environment out of its `IORef`, then passing the result to `extendEnv`, then returning a new `IORef` with the extended environment. Now that we have all our environment functions, we need to start using them in the evaluator. Since Haskell has no global variables, we\'ll have to thread the environment through the evaluator as a parameter. While we\'re at it, we might as well add the `set!` and `define` special forms. ``` haskell eval :: Env -> LispVal -> IOThrowsError LispVal eval env val@(String _) = return val eval env val@(Number _) = return val eval env val@(Bool _) = return val eval env (Atom id) = getVar env id eval env (List [Atom "quote", val]) = return val eval env (List [Atom "if", pred, conseq, alt]) = do result <- eval env pred case result of Bool False -> eval env alt otherwise -> eval env conseq eval env (List [Atom "set!", Atom var, form]) = eval env form >>= setVar env var eval env (List [Atom "define", Atom var, form]) = eval env form >>= defineVar env var eval env (List (Atom func : args)) = mapM (eval env) args >>= liftThrows . apply func eval env badForm = throwError $ BadSpecialForm "Unrecognized special form" badForm ``` Since a single environment gets threaded through a whole interactive session, we need to change a few of our IO functions to take an environment. ``` haskell evalAndPrint :: Env -> String -> IO () evalAndPrint env expr = evalString env expr >>= putStrLn evalString :: Env -> String -> IO String evalString env expr = runIOThrows $ liftM show $ (liftThrows $ readExpr expr) >>= eval env ``` We need the `runIOThrows` in evalString because the type of the monad has changed from `ThrowsError` to `IOThrowsError`. Similarly, we need a `liftThrows` to bring `readExpr` into the `IOThrowsError` monad. Next, we initialize the environment with a null variable before starting the program: ``` haskell runOne :: String -> IO () runOne expr = nullEnv >>= flip evalAndPrint expr runRepl :: IO () runRepl = nullEnv >>= until_ (== "quit") (readPrompt "Lisp>>> ") . evalAndPrint ``` We\'ve created an additional helper function runOne to handle the single-expression case, since it\'s now somewhat more involved than just running `evalAndPrint`. The changes to `runRepl` are a bit more subtle: notice how we added a function composition operator before evalAndPrint. That\'s because `evalAndPrint` now takes an additional `Env` parameter, fed from `nullEnv`. The function composition tells `until_` that instead of taking plain old `evalAndPrint` as an action, it ought to apply it first to whatever\'s coming down the monadic pipeline, in this case the result of `nullEnv`. Thus, the actual function that gets applied to each line of input is `(evalAndPrint env)`, just as we want it. Finally, we need to change our main function to call `runOne` instead of evaluating `evalAndPrint` directly: ``` haskell main :: IO () main = do args <- getArgs case length args of 0 -> runRepl 1 -> runOne $ args !! 0 otherwise -> putStrLn "Program takes only 0 or 1 argument" ``` And we can compile and test our program: `$ ghc -package parsec -o lisp [../code/listing8.hs listing8.hs]`\ `$ ./lisp`\ `Lisp>>> (define x 3)`\ `3`\ `Lisp>>> (+ x 2)`\ `5`\ `Lisp>>> (+ y 2)`\ `Getting an unbound variable: y`\ `Lisp>>> (define y 5)`\ `5`\ `Lisp>>> (+ x (- y 2))`\ `6`\ `Lisp>>> (define str "A string")`\ `"A string"`\ `Lisp>>> (< str "The string")`\ `Invalid type: expected number, found "A string"`\ `Lisp>>> (string<? str "The string")`\ `#t`
# Write Yourself a Scheme in 48 Hours/Defining Scheme Functions Now that we can define variables, we might as well extend it to functions. After this section, you\'ll be able to define your own functions within Scheme and use them from other functions. Our implementation is nearly finished. Let\'s start by defining new `LispVal` constructors: ``` haskell \| PrimitiveFunc ([LispVal] -> ThrowsError LispVal) \| Func { params :: [String], vararg :: (Maybe String), body :: [LispVal], closure :: Env } ``` We\'ve added a separate constructor for primitives, because we\'d like to be able to store `+`, `eqv?`, etc. in variables and pass them to functions. The `PrimitiveFunc` constructor stores a function that takes a list of arguments to a `ThrowsError LispVal`, the same type that is stored in our primitive list. We also want a constructor to store user-defined functions. We store four pieces of information: 1. the names of the parameters, as they\'re bound in the function body; 2. whether the function accepts a variable-length list of arguments, and if so, the variable name it\'s bound to; 3. the function body, as a list of expressions; 4. the environment that the function was created in. This is an example of a record type. Records are somewhat clumsy in Haskell, so we\'re only using them for demonstration purposes. However, they can be invaluable in large-scale programming. Next, we\'ll want to edit our `show` function to include the new types: ``` haskell showVal (PrimitiveFunc _) = "<primitive>" showVal (Func {params = args, vararg = varargs, body = body, closure = env}) = "(lambda (" ++ unwords (map show args) ++ (case varargs of Nothing -> "" Just arg -> " . " ++ arg) ++ ") ...)" ``` Instead of showing the full function, we just print out the word `<primitive>` for primitives and the header info for user-defined functions. This is an example of pattern-matching for records: as with normal algebraic types, a pattern looks exactly like a constructor call. Field names come first and the variables they\'ll be bound to come afterwards. Next, we need to change `apply`. Instead of being passed the name of a function, it\'ll be passed a `LispVal` representing the actual function. For primitives, that makes the code simpler: we need only read the function out of the value and apply it. ``` haskell apply :: LispVal -> [LispVal] -> IOThrowsError LispVal apply (PrimitiveFunc func) args = liftThrows $ func args ``` The interesting code happens when we\'re faced with a user defined function. Records let you pattern match on both the field name (as shown above) or the field position, so we\'ll use the latter form: ``` haskell apply (Func params varargs body closure) args = if num params /= num args && varargs == Nothing then throwError $ NumArgs (num params) args else (liftIO $ bindVars closure $ zip params args) >>= bindVarArgs varargs >>= evalBody where remainingArgs = drop (length params) args num = toInteger . length evalBody env = liftM last $ mapM (eval env) body bindVarArgs arg env = case arg of Just argName -> liftIO $ bindVars env [(argName, List $ remainingArgs)] Nothing -> return env ``` The very first thing this function does is check the length of the parameter list against the expected number of arguments. It throws an error if they don\'t match. We define a local function `num` to enhance readability and make the program a bit shorter. Assuming the call is valid, we do the bulk of the call in monadic pipeline that binds the arguments to a new environment and executes the statements in the body. The first thing we do is zip the list of parameter names and the list of (already evaluated) argument values together into a list of pairs. Then, we take that and the function\'s closure (not the current environment -- this is what gives us lexical scoping) and use them to create a new environment to evaluate the function in. The result is of type `IO`, while the function as a whole is `IOThrowsError`, so we need to `liftIO` it into the combined monad. Now it\'s time to bind the remaining arguments to the varargs variable, using the local function `bindVarArgs`. If the function doesn\'t take `varargs` (the `Nothing` clause), then we just return the existing environment. Otherwise, we create a singleton list that has the variable name as the key and the remaining args as the value, and pass that to bindVars. We define the local variable `remainingArgs` for readability, using the built-in function `drop` to ignore all the arguments that have already been bound to variables. The final stage is to evaluate the body in this new environment. We use the local function `evalBody` for this, which maps the monadic function `eval env` over every statement in the body, and then returns the value of the last statement. Since we\'re now storing primitives as regular values in variables, we have to bind them when the program starts up: ``` haskell primitiveBindings :: IO Env primitiveBindings = nullEnv >>= (flip bindVars $ map makePrimitiveFunc primitives) where makePrimitiveFunc (var, func) = (var, PrimitiveFunc func) ``` This takes the initial null environment, makes a bunch of name/value pairs consisting of PrimitiveFunc wrappers, and then binds the new pairs into the new environment. We also want to change `runOne` and `runRepl` to `primitiveBindings` instead: ``` haskell runOne :: String -> IO () runOne expr = primitiveBindings >>= flip evalAndPrint expr runRepl :: IO () runRepl = primitiveBindings >>= until_ (== "quit") (readPrompt "Lisp>>> ") . evalAndPrint ``` Finally, we need to change the evaluator to support `lambda` and function `define`. We\'ll start by creating a few helper functions to make it a little easier to create function objects in the `IOThrowsError` monad: ``` haskell makeFunc varargs env params body = return $ Func (map showVal params) varargs body env makeNormalFunc = makeFunc Nothing makeVarArgs = makeFunc . Just . showVal ``` Here, `makeNormalFunc` and `makeVarArgs` should just be considered specializations of `makeFunc` with the first argument set appropriately for normal functions vs. variable args. This is a good example of how to use first-class functions to simplify code. Now, we can use them to add our extra eval clauses. They should be inserted after the define-variable clause and before the function-application one: ``` haskell eval env (List (Atom "define" : List (Atom var : params) : body)) = makeNormalFunc env params body >>= defineVar env var eval env (List (Atom "define" : DottedList (Atom var : params) varargs : body)) = makeVarArgs varargs env params body >>= defineVar env var eval env (List (Atom "lambda" : List params : body)) = makeNormalFunc env params body eval env (List (Atom "lambda" : DottedList params varargs : body)) = makeVarArgs varargs env params body eval env (List (Atom "lambda" : varargs@(Atom _) : body)) = makeVarArgs varargs env [] body ``` The following needs to replace the prior function-application eval clause. ``` haskell eval env (List (function : args)) = do func <- eval env function argVals <- mapM (eval env) args apply func argVals ``` As you can see, they just use pattern matching to destructure the form and then call the appropriate function helper. In define\'s case, we also feed the output into `defineVar` to bind a variable in the local environment. We also need to change the function application clause to remove the `liftThrows` function, since apply now works in the `IOThrowsError` monad. We can now compile and run our program, and use it to write real programs! `$ ghc -package parsec -fglasgow-exts -o lisp [../code/listing9.hs listing9.hs]`\ `$ ./lisp`\ `Lisp>>> (define (f x y) (+ x y))`\ `(lambda ("x" "y") ...)`\ `Lisp>>> (f 1 2)`\ `3`\ `Lisp>>> (f 1 2 3)`\ `Expected 2 args; found values 1 2 3`\ `Lisp>>> (f 1)`\ `Expected 2 args; found values 1`\ `Lisp>>> (define (factorial x) (if (= x 1) 1 (* x (factorial (- x 1)))))`\ `(lambda ("x") ...)`\ `Lisp>>> (factorial 10)`\ `3628800`\ `Lisp>>> (define (counter inc) (lambda (x) (set! inc (+ x inc)) inc))`\ `(lambda ("inc") ...)`\ `Lisp>>> (define my-count (counter 5))`\ `(lambda ("x") ...)`\ `Lisp>>> (my-count 3)`\ `8`\ `Lisp>>> (my-count 6)`\ `14`\ `Lisp>>> (my-count 5)`\ `19`
# Write Yourself a Scheme in 48 Hours/Creating IO Primitives Our Scheme can\'t really communicate with the outside world yet, so it would be nice if we could give it some I/O functions. Also, it gets really tedious typing in functions every time we start the interpreter, so it would be nice to load files of code and execute them. The first thing we\'ll need is a new constructor for `LispVal`s. `PrimitiveFunc`s have a specific type signature that doesn\'t include the IO monad, so they can\'t perform any IO. We want a dedicated constructor for primitive functions that perform IO: ``` haskell \| IOFunc ([LispVal] -> IOThrowsError LispVal) ``` While we\'re at it, let\'s also define a constructor for the Scheme data type of a port. Most of our IO functions will take one of these to read from or write to: ``` haskell \| Port Handle ``` A `Handle` is basically the Haskell notion of a port: it\'s an opaque data type, returned from `openFile` and similar IO actions, that you can read and write to. For completeness, we ought to provide `showVal` methods for the new data types: ``` haskell showVal (Port _) = "<IO port>" showVal (IOFunc _) = "<IO primitive>" ``` This\'ll let the REPL function properly and not crash when you use a function that returns a port. We also need to update apply, so that it can handle `IOFuncs`: ``` haskell apply (IOFunc func) args = func args ``` We\'ll need to make some minor changes to our parser to support `load`. Since Scheme files usually contain several definitions, we need to add a parser that will support several expressions, separated by whitespace. And it also needs to handle errors. We can reuse much of the existing infrastructure by factoring our basic readExpr so that it takes the actual parser as a parameter: ``` haskell readOrThrow :: Parser a -> String -> ThrowsError a readOrThrow parser input = case parse parser "lisp" input of Left err -> throwError $ Parser err Right val -> return val readExpr = readOrThrow parseExpr readExprList = readOrThrow (endBy parseExpr spaces) ``` Again, think of both `readExpr` and `readExprList` as specializations of the newly-renamed `readOrThrow`. We\'ll be using `readExpr` in our REPL to read single expressions; we\'ll be using `readExprList` from within load to read programs. Next, we\'ll want a new list of IO primitives, structured just like the existing primitive list: ``` haskell ioPrimitives :: [(String, [LispVal] -> IOThrowsError LispVal)] ioPrimitives = [("apply", applyProc), ("open-input-file", makePort ReadMode), ("open-output-file", makePort WriteMode), ("close-input-port", closePort), ("close-output-port", closePort), ("read", readProc), ("write", writeProc), ("read-contents", readContents), ("read-all", readAll)] ``` The only difference here is in the type signature. Unfortunately, we can\'t use the existing primitive list because lists cannot contain elements of different types. We also need to change the definition of `primitiveBindings` to add our new primitives: ``` haskell primitiveBindings :: IO Env primitiveBindings = nullEnv >>= (flip bindVars $ map (makeFunc IOFunc) ioPrimitives ++ map (makeFunc PrimitiveFunc) primitives) where makeFunc constructor (var, func) = (var, constructor func) ``` We\'ve generalized makeFunc to take a constructor argument, and now call it on the list of `ioPrimitives` in addition to the plain old primitives. Now we start defining the actual functions. `applyProc` is a very thin wrapper around apply, responsible for destructuring the argument list into the form apply expects: ``` haskell applyProc :: [LispVal] -> IOThrowsError LispVal applyProc [func, List args] = apply func args applyProc (func : args) = apply func args ``` `makePort` wraps the Haskell function `openFile`, converting it to the right type and wrapping its return value in the `Port` constructor. It\'s intended to be partially-applied to the `IOMode`, `ReadMode` for `open-input-file` and `WriteMode` for `open-output-file`: ``` haskell makePort :: IOMode -> [LispVal] -> IOThrowsError LispVal makePort mode [String filename] = liftM Port $ liftIO $ openFile filename mode ``` `closePort` also wraps the equivalent Haskell procedure, this time `hClose`: ``` haskell closePort :: [LispVal] -> IOThrowsError LispVal closePort [Port port] = liftIO $ hClose port >> (return $ Bool True) closePort _ = return $ Bool False ``` `readProc` (named to avoid a name conflict with the built-in read) wraps the Haskell `hGetLine` and then sends the result to `parseExpr`, to be turned into a `LispVal` suitable for Scheme: ``` haskell readProc :: [LispVal] -> IOThrowsError LispVal readProc [] = readProc [Port stdin] readProc [Port port] = (liftIO $ hGetLine port) >>= liftThrows . readExpr ``` Notice how `hGetLine port` is of type `IO String` yet `readExpr` is of type `String -> ThrowsError LispVal`, so they both need to be converted (with `liftIO` and `liftThrows`, respectively) to the `IOThrowsError` monad. Only then can they be piped together with the monadic bind operator. `writeProc` converts a `LispVal` to a string and then writes it out on the specified port: ``` haskell writeProc :: [LispVal] -> IOThrowsError LispVal writeProc [obj] = writeProc [obj, Port stdout] writeProc [obj, Port port] = liftIO $ hPrint port obj >> (return $ Bool True) ``` We don\'t have to explicitly call show on the object we\'re printing, because `hPrint` takes a value of type `Show a`. It\'s calling show for us automatically. This is why we bothered making `LispVal` an instance of `Show`; otherwise, we wouldn\'t be able to use this automatic conversion and would have to call `showVal` ourselves. Many other Haskell functions also take instances of `Show`, so if we\'d extended this with other IO primitives, it could save us significant labor. `readContents` reads the whole file into a string in memory. It\'s a thin wrapper around Haskell\'s `readFile`, again just lifting the IO action into an `IOThrowsError` action and wrapping it in a `String` constructor: ``` haskell readContents :: [LispVal] -> IOThrowsError LispVal readContents [String filename] = liftM String $ liftIO $ readFile filename ``` The helper function `load` doesn\'t do what Scheme\'s load does (we handle that later). Rather, it\'s responsible only for reading and parsing a file full of statements. It\'s used in two places: `readAll` (which returns a list of values) and `load` (which evaluates those values as Scheme expressions). ``` haskell load :: String -> IOThrowsError [LispVal] load filename = (liftIO $ readFile filename) >>= liftThrows . readExprList ``` `readAll` then just wraps that return value with the `List` constructor: ``` haskell readAll :: [LispVal] -> IOThrowsError LispVal readAll [String filename] = liftM List $ load filename ``` Implementing the actual Scheme `load` function is a little tricky, because `load` can introduce bindings into the local environment. Apply, however, doesn\'t take an environment argument, and so there\'s no way for a primitive function (or any function) to do this. We get around this by implementing `load` as a special form: ``` haskell eval env (List [Atom "load", String filename]) = load filename >>= liftM last . mapM (eval env) ``` Finally, we might as well change our `runOne` function so that instead of evaluating a single expression from the command line, it takes the name of a file to execute and runs that as a program. Additional command-line arguments will get bound into a list `args` within the Scheme program: ``` haskell runOne :: [String] -> IO () runOne args = do env <- primitiveBindings >>= flip bindVars [("args", List $ map String $ drop 1 args)] (runIOThrows $ liftM show $ eval env (List [Atom "load", String (args !! 0)])) >>= hPutStrLn stderr ``` That\'s a little involved, so let\'s go through it step-by-step. The first line takes the original primitive bindings, passes that into `bindVars`, and then adds a variable named `args` that\'s bound to a `List` containing `String` versions of all but the first argument. (The first argument is the filename to execute.) Then, it creates a Scheme form `load "``arg1``"`, just as if the user had typed it in, and evaluates it. The result is transformed to a string (remember, we have to do this before catching errors, because the error handler converts them to strings and the types must match) and then we run the whole `IOThrowsError` action. Then we print the result on `stderr`. (Traditional UNIX conventions hold that `stdout` should be used only for program output, with any error messages going to `stderr`. In this case, we\'ll also be printing the return value of the last statement in the program, which generally has no meaning to anything.) Then we change main so it uses our new `runOne` function. Since we no longer need a third clause to handle the wrong number of command-line arguments, we can simplify it to an if statement: ``` haskell main :: IO () main = do args <- getArgs if null args then runRepl else runOne $ args ```
# Write Yourself a Scheme in 48 Hours/Towards a Standard Library Our Scheme is almost complete now, but it\'s still rather hard to use. At the very least, we\'d like a library of standard list manipulation functions that we can use to perform some common computations. Rather than using a typical Scheme implementation, defining each list function in terms of a recursion on lists, we\'ll implement two primitive recursion operators (`fold` and `unfold`) and then define our whole library based on those. This style is used by the Haskell Prelude: it gives you more concise definitions, less room for error, and good practice using fold to capture iteration. We\'ll start by defining a few obvious helper functions. `not` and `null` are defined exactly as you\'d expect it, using if statements: ``` scheme (define (not x) (if x #f #t)) (define (null? obj) (if (eqv? obj '()) #t #f)) ``` We can use the varargs feature to define list, which just returns a list of its arguments: ``` scheme (define (list . objs) objs) ``` We also want an `id` function, which just returns its argument unchanged. This may seem completely useless -- if you already have a value, why do you need a function to return it? However, several of our algorithms expect a function that tells us what to do with a given value. By defining `id`, we let those higher-order functions work even if we don\'t want to do anything with the value. ``` scheme (define (id obj) obj) ``` Similarly, it\'d be nice to have a `flip` function, in case we want to pass in a function that takes its arguments in the wrong order: ``` scheme (define (flip func) (lambda (arg1 arg2) (func arg2 arg1))) ``` Finally, we add `curry` and `compose`, which work like their Haskell equivalents (partial application and the dot operator, respectively). ``` scheme (define (curry func arg1) (lambda (arg) (apply func (cons arg1 (list arg))))) (define (compose f g) (lambda (arg) (f (apply g arg)))) ``` We might as well define some simple library functions that appear in the Scheme standard: ``` scheme (define zero? (curry = 0)) (define positive? (curry < 0)) (define negative? (curry > 0)) (define (odd? num) (= (mod num 2) 1)) (define (even? num) (= (mod num 2) 0)) ``` These are basically done just as you\'d expect them. Note the usage of curry to define `zero?`, `positive?` and `negative?`. We bind the variable `zero?` to the function returned by curry, giving us a unary function that returns true if its argument is equal to zero. Next, we want to define a fold function that captures the basic pattern of recursion over a list. The best way to think about fold is to picture a list in terms of its infix constructors: `[1, 2, 3, 4] = 1:2:3:4:[]` in Haskell or `(1 . (2 . (3 . (4 . NIL))))` in Scheme. A fold function replaces every constructor with a binary operation, and replaces `NIL` with the accumulator. So, for example, `(fold + 0 '(1 2 3 4)) = (1 + (2 + (3 + (4 + 0))))`. With that definition, we can write our fold function. Start with a right-associative version to mimic the above examples: ``` scheme (define (foldr func end lst) (if (null? lst) end (func (car lst) (foldr func end (cdr lst))))) ``` The structure of this function mimics our definition almost exactly. If the list is null, replace it with the end value. If not, apply the function to the car of the list and to the result of folding this function and end value down the rest of the list. Since the right-hand operand is folded up first, you end up with a right-associative fold. We also want a left-associative version. For most associative operations like `+` and `,` the two of them are completely equivalent. However, there is at least one important binary operation that is not* associative: cons. For all our list manipulation functions, then, we\'ll need to deliberately choose between left- and right-associative folds. ``` scheme (define (foldl func accum lst) (if (null? lst) accum (foldl func (func accum (car lst)) (cdr lst)))) ``` This begins the same way as the right-associative version, with the test for null that returns the accumulator. This time, however, we apply the function to the accumulator and first element of the list, instead of applying it to the first element and the result of folding the list. This means that we process the beginning first, giving us left-associativity. Once we reach the end of the list, `'()`, we then return the result that we\'ve been progressively building up. Note that func takes its arguments in the opposite order from `foldr`. In `foldr`, the accumulator represents the rightmost value to tack onto the end of the list, after you\'ve finished recursing down it. In `foldl`, it represents the completed calculation for the leftmost part of the list. In order to preserve our intuitions about commutativity of operators, it should therefore be the left argument of our operation in `foldl`, but the right argument in `foldr`. Once we\'ve got our basic folds, we can define a couple of convenience names to match typical Scheme usage: ``` scheme (define fold foldl) (define reduce foldr) ``` These are just new variables bound to the existing functions: they don\'t define new functions. Most Schemes call `fold` \"`reduce`\" or plain old \"`fold`\", and don\'t make the distinction between `foldl` and `foldr`. We define it to be `foldl`, which happens to be tail-recursive and hence runs more efficiently than `foldr` (it doesn\'t have to recurse all the way down to the end of the list before it starts building up the computation). Not all operations are associative, however; we\'ll see some cases later where we have to use `foldr` to get the right result. Next, we want to define a function that is the opposite of `fold`. Given a unary function, an initial value, and a unary predicate, it continues applying the function to the last value until the predicate is true, building up a list as it goes along. ``` scheme (define (unfold func init pred) (if (pred init) (cons init '()) (cons init (unfold func (func init) pred)))) ``` As usual, our function structure basically matches the definition. If the predicate is true, then we cons a `'()` onto the last value, terminating the list. Otherwise, cons the result of unfolding the next value `(func init)` onto the current value. In academic functional programming literature, folds are often called catamorphisms, unfolds are often called anamorphisms, and the combinations of the two are often called hylomorphisms. They\'re interesting because any for-each loop can be represented as a catamorphism. To convert from a loop to a foldl, package up all mutable variables in the loop into a data structure (records work well for this, but you can also use an algebraic data type or a list). The initial state becomes the accumulator; the loop body becomes a function with the loop variables as its first argument and the iteration variable as its second; and the list becomes, well, the list. The result of the fold function is the new state of all the mutable variables. Similarly, every for-loop (without early exits) can be represented as a hylomorphism. The initialization, termination, and step conditions of a for-loop define an anamorphism that builds up a list of values for the iteration variable to take. Then, you can treat that as a for-each loop and use a catamorphism to break it down into whatever state you wish to modify. Let\'s go through a couple examples. We\'ll start with typical `sum`, `product`, `and` & `or` functions: ``` scheme (define (sum . lst) (fold + 0 lst)) (define (product . lst) (fold * 1 lst)) (define (and . lst) (fold && #t lst)) (define (or . lst) (fold \|\| #f lst)) ``` These all follow from the definitions: - `(sum 1 2 3 4) = 1 + 2 + 3 + 4 + 0 = (fold + 0 '(1 . (2 . (3 . (4 . NIL)))))` - `(product 1 2 3 4) = 1 * 2 * 3 * 4 * 1 = (fold * 1 '(1 . (2 . (3 . (4 . NIL)))))` - `(and #t #t #f) = #t && #t && #f && #t = (fold && #t '(#t . (#t . (#f . NIL))))` - `(or #t #t #f) = #t \|\| #t \|\| #f \|\| #f = (fold \|\| #f '(#t . (#t . (#f . NIL))))` Since all of these operators are associative, it doesn\'t matter whether we use `foldr` or `foldl`. We replace the cons constructor with the operator, and the nil constructor with the identity element for that operator. Next, let\'s try some more complicated operators. `max` and `min` find the maximum and minimum of their arguments, respectively: ``` scheme (define (max first . rest) (fold (lambda (old new) (if (> old new) old new)) first rest)) (define (min first . rest) (fold (lambda (old new) (if (< old new) old new)) first rest)) ``` It\'s not immediately obvious what operation to fold over the list, because none of the built-ins quite qualify. Instead, think back to fold as a representation of a foreach loop. The accumulator represents any state we\'ve maintained over previous iterations of the loop, so we\'ll want it to be the maximum value we\'ve found so far. That gives us our initialization value: we want to start off with the leftmost variable in the list (since we\'re doing a `foldl`). Now recall that the result of the operation becomes the new accumulator at each step, and we\'ve got our function. If the previous value is greater, keep it. If the new value is greater, or they\'re equal, return the new value. Reverse the operation for `min`. How about `length`? We know that we can find the length of a list by counting down it, but how do we translate that into a fold? ``` scheme (define (length lst) (fold (lambda (x y) (+ x 1)) 0 lst)) ``` Again, think in terms of its definition as a loop. The accumulator starts off at 0 and gets incremented by 1 with each iteration. That gives us both our initialization value, 0, and our function, `(lambda (x y) (+ x 1))`. Another way to look at this is \"The length of a list is 1 + the length of the sublist to its left\". Let\'s try something a bit trickier: `reverse`. ``` scheme (define (reverse lst) (fold (flip cons) '() lst)) ``` The function here is fairly obvious: if you want to reverse two `cons` cells, you can just `flip cons` so it takes its arguments in the opposite order. However, there\'s a bit of subtlety at work. Ordinary lists are right associative: `(1 2 3 4) = (1 . (2 . (3 . (4 . NIL))))`. If you want to reverse this, you need your fold to be left associative: `(reverse '(1 2 3 4)) = (4 . (3 . (2 . (1 . NIL))))`. Try it with a `foldr` instead of a foldl and see what you get. There\'s a whole family of `member` and `assoc` functions, all of which can be represented with folds. The particular lambda expression is fairly complicated though, so let\'s factor it out: ``` scheme (define (mem-helper pred op) (lambda (acc next) (if (and (not acc) (pred (op next))) next acc))) (define (memq obj lst) (fold (mem-helper (curry eq? obj) id) #f lst)) (define (memv obj lst) (fold (mem-helper (curry eqv? obj) id) #f lst)) (define (member obj lst) (fold (mem-helper (curry equal? obj) id) #f lst)) (define (assq obj alist) (fold (mem-helper (curry eq? obj) car) #f alist)) (define (assv obj alist) (fold (mem-helper (curry eqv? obj) car) #f alist)) (define (assoc obj alist) (fold (mem-helper (curry equal? obj) car) #f alist)) ``` The helper function is parameterized by the predicate to use and the operation to apply to the result if found. Its accumulator represents the first value found so far: it starts out with `#f` and takes on the first value that satisfies its predicate. We avoid finding subsequent values by testing for a non-`#f` value and returning the existing accumulator if it\'s already set. We also provide an operation that will be applied to the next value each time the predicate tests: this lets us customize `mem-helper` to check the value itself (for `member`) or only the key of the value (for `assoc`). The rest of the functions are just various combinations of `eq?`, `eqv?`, `equal?` and `id`, `car`, folded over the list with an initial value of `#f`. Next, let\'s define the functions `map` and `filter`. `map` applies a function to every element of a list, returning a new list with the transformed values: ``` scheme (define (map func lst) (foldr (lambda (x y) (cons (func x) y)) '() lst)) ``` Remember that `foldr`\'s function takes its arguments in the opposite order as `fold`, with the current value on the left. Map\'s lambda applies the function to the current value, then conses it with the rest of the mapped list, represented by the right-hand argument. It\'s essentially replacing every infix cons constructor with one that conses, but also applies the function to its left-side argument. `filter` keeps only the elements of a list that satisfy a predicate, dropping all others: ``` scheme (define (filter pred lst) (foldr (lambda (x y) (if (pred x) (cons x y) y)) '() lst)) ``` This works by testing the current value against the predicate. If it\'s true, replacing cons with `cons`, i.e., don\'t do anything. If it\'s false, drop the `cons` and just return the rest of the list. This eliminates all the elements that don\'t satisfy the predicate, consing up a new list that includes only the ones that do. We can use the standard library by starting up our Lisp interpreter and typing `(load "stdlib.scm")`: `$ ./lisp`\ `Lisp>>> (load "stdlib.scm")`\ `(lambda ("pred" . lst) ...)`\ `Lisp>>> (map (curry + 2) '(1 2 3 4))`\ `(3 4 5 6)`\ `Lisp>>> (filter even? '(1 2 3 4))`\ `(2 4)`\ `Lisp>>> quit` There are many other useful functions that could go into the standard library, including `list-tail`, `list-ref`, append, and various string-manipulation functions. Try implementing them as folds. Remember, the key to successful fold programming is thinking only in terms of what happens on each iteration. Fold captures the pattern of recursion down a list, and recursive problems are best solved by working one step at a time.
# Write Yourself a Scheme in 48 Hours/Conclusion You now have a working Scheme interpreter that implements a large chunk of the standard, including functions, lambdas, lexical scoping, symbols, strings, integers, list manipulation, and assignment. You can use it interactively, with a REPL, or in batch mode, running script files. You can write libraries of Scheme functions and either include them in programs or load them into the interactive interpreter. With a little text processing via awk or sed, you can format the output of UNIX commands as parenthesized Lisp lists, read them into a Scheme program, and use this interpreter for shell scripting. There are still a number of features you could add to this interpreter. Hygienic macros let you perform transformations on the source code before it\'s executed. They\'re a very convenient feature for adding new language features, and several standard parts of Scheme (such as let-bindings and additional control flow features) are defined in terms of them. Section 4.3 of R5RS defines the macro system\'s syntax and semantics, and there is a whole collection of papers on implementation. Basically, you\'d want to intersperse a function between readExpr and eval that takes a form and a macro environment, looks for transformer keywords, and then transforms them according to the rules of the pattern language, rewriting variables as necessarily. Continuations are a way of capturing \"the rest of the computation\", saving it, and perhaps executing it more than once. Using them, you can implement just about every control flow feature in every major programming language. The easiest way to implement continuations is to transform the program into continuation-passing style, so that eval takes an additional continuation argument and calls it, instead of returning a result. This parameter gets threaded through all recursive calls to eval, but is only manipulated when evaluating a call to call-with-current-continuation. Dynamic-wind could be implemented by keeping a stack of functions to execute when leaving the current continuation and storing (inside the continuation data type) a stack of functions to execute when resuming the continuation. If you\'re just interested in learning more Haskell, there are a large number of libraries that may help: - For webapps: WASH, a monadic web framework - For databases: haskelldb, a library that wraps SQL as a set of Haskell functions, giving you all the type-safety of the language when querying the database - For GUI programming: Fudgets and wxHaskell. wxHaskell is more of a conventional MVC GUI library, while Fudgets includes a lot of new research about how to represent GUIs in functional programming languages - For concurrency: Software Transactional Memory, described in the paper Composable Memory Transactions - For networking: GHC\'s Networking libraries This should give you a starting point for further investigations into the language. Happy hacking! ## Acknowledgements Thanks to Ketil Malde, Pete Kazmier, and Brock for sending in questions and suggestions about this tutorial. Additional comments, clarifications, and corrections should go on the discussion page of this tutorial.
# Write Yourself a Scheme in 48 Hours/Answers \| author = \| section = Answers \| previous = [[../Conclusion\|Conclusion]] \| next = \| notes = }} ``` \_\_TOC\_\_ # Chapter 1 ### Exercise 1 `main :: IO ()`\ `main = do args <- getArgs`\ ` putStrLn ("Hello, " ++ args!!0 ++ " " ++ args!!1)` ### Exercise 2 `main :: IO ()`\ `main = do args <- getArgs`\ ` print ((read $ args!!0) + (read $ args!!1))` The `$` operator reduces the number of parentheses needed here. Alternatively you could write the function applications as `read (args!!0)`. ### Exercise 3 `main :: IO ()`\ `main = do putStrLn "What do they call thee at home?"`\ ` name <- getLine`\ ` putStrLn ("Ey up " ++ name)` # Chapter 2 ## Section 3 - Parsing ### Exercise 1 #### Part 1 `parseNumber :: Parser LispVal`\ `parseNumber = do x <- many1 digit`\ ` (return . Number . read) x` #### Part 2 In order to answer this question, you need to do a bit of detective work! It is helpful to read up on do notation. Using the information there, we can mechanically transform the above answer into the following. `parseNumber = many1 digit >>= \x -> (return . Number . read) x` This can be cleaned up into the following: `parseNumber = many1 digit >>= return . Number . read` ### Exercise 2 We need to create a new parser action that accepts a backslash followed by either another backslash or a doublequote. This action needs to return only the second character. `escapedChars :: Parser Char`\ `escapedChars = do char '\\' -- a backslash`\ ` x <- oneOf "\\\"" -- either backslash or doublequote`\ ` return x -- return the escaped character` Once that is done, we need to make some changes to parseString. `parseString :: Parser LispVal`\ `parseString = do char '"'`\ ` x <- many $ escapedChars <\|> noneOf "\"\\"`\ ` char '"'`\ ` return $ String x` ### Exercise 3 `escapedChars :: Parser Char`\ `escapedChars = do char '\\' `\ ` x <- oneOf "\\\"nrt" `\ ` return $ case x of `\ ` '\\' -> x`\ ` '"' -> x`\ ` 'n' -> '\n'`\ ` 'r' -> '\r'`\ ` 't' -> '\t'` ### Exercise 4 First, it is necessary to change the definition of symbol. `symbol :: Parser Char`\ `symbol = oneOf "!$%&\|+-/:<=>?@^_~"` This means that it is no longer possible to begin an atom with the hash character. This necessitates a different way of parsing #t and #f. `parseBool :: Parser LispVal`\ `parseBool = do`\ ` char '#'`\ ` (char 't' >> return (Bool True)) <\|> (char 'f' >> return (Bool False))` This in turn requires us to make changes to parseExpr. `parseExpr :: Parser LispVal`\ `parseExpr = parseAtom`\ ` <\|> parseString`\ ` <\|> parseNumber`\ ` <\|> parseBool` parseNumber need to be changed to the following. `parseNumber :: Parser LispVal`\ `parseNumber = parseDecimal1 <\|> parseDecimal2 <\|> parseHex <\|> parseOct <\|> parseBin` And the following new functions need to be added. `parseDecimal1 :: Parser LispVal`\ `parseDecimal1 = many1 digit >>= (return . Number . read)` `parseDecimal2 :: Parser LispVal`\ `parseDecimal2 = do try $ string "#d"`\ ` x <- many1 digit`\ ` (return . Number . read) x` `parseHex :: Parser LispVal`\ `parseHex = do try $ string "#x"`\ ` x <- many1 hexDigit`\ ` return $ Number (hex2dig x)` `parseOct :: Parser LispVal`\ `parseOct = do try $ string "#o"`\ ` x <- many1 octDigit`\ ` return $ Number (oct2dig x)` `parseBin :: Parser LispVal`\ `parseBin = do try $ string "#b"`\ ` x <- many1 (oneOf "10")`\ ` return $ Number (bin2dig x)` `oct2dig x = fst $ readOct x !! 0`\ `hex2dig x = fst $ readHex x !! 0`\ `bin2dig = bin2dig' 0`\ `bin2dig' digint "" = digint`\ `bin2dig' digint (x:xs) = let old = 2 digint + (if x == '0' then 0 else 1) in`\ ` bin2dig' old xs` Import the Numeric module to use the readOct and readHex functions. ### Exercise 5 `data LispVal = Atom String`\ ` \| List [LispVal]`\ ` \| DottedList [LispVal] LispVal`\ ` \| Number Integer`\ ` \| String String`\ ` \| Bool Bool`\ ` \| Character Char` `parseCharacter :: Parser LispVal`\ `parseCharacter = do`\ ` try $ string "#\\"`\ ` value <- try (string "newline" <\|> string "space") `\ ` <\|> do { x <- anyChar; notFollowedBy alphaNum ; return [x] }`\ ` return $ Character $ case value of`\ ` "space" -> ' '`\ ` "newline" -> '\n'`\ ` otherwise -> (value !! 0)` The combination of anyChar and notFollowedBy ensure that only a single character is read. Note that this does not actually conform to the standard; as it stands, \"space\" and \"newline\" must be entirely lowercase; the standard states that they should be case insensitive. `parseExpr :: Parser LispVal`\ `parseExpr = parseAtom`\ ` <\|> parseString`\ ` <\|> try parseNumber -- we need the 'try' because `\ ` <\|> try parseBool -- these can all start with the hash char`\ ` <\|> try parseCharacter` ### Exercise 6 A possible solution for floating point numbers: ` parseFloat :: Parser LispVal`\ ` parseFloat = do x <- many1 digit`\ ` char '.'`\ ` y <- many1 digit`\ ` return $ Float (fst.head$readFloat (x++"."++y))` Furthermore, add ` try parseFloat` before parseNumber in parseExpr and the line ` \| Float Double` to the LispVal type. ### Exercise 7 Ratio, using Haskell\'s Rational type: ` parseRatio :: Parser LispVal`\ ` parseRatio = do x <- many1 digit`\ ` char '/'`\ ` y <- many1 digit`\ ` return $ Ratio ((read x) % (read y))` Additionally, import the Data.Ratio module, add ` try parseRatio` before parseNumber in parseExpr and the line ` \| Ratio Rational` to the LispVal type. Real is already implemented in the Float type from Exercise 6, unless I\'m mistaken. Complex using Haskell\'s Complex type: ` toDouble :: LispVal -> Double`\ ` toDouble(Float f) = realToFrac f`\ ` toDouble(Number n) = fromIntegral n` ` parseComplex :: Parser LispVal`\ ` parseComplex = do x <- (try parseFloat <\|> parseDecimal)`\ ` char '+' `\ ` y <- (try parseFloat <\|> parseDecimal)`\ ` char 'i' `\ ` return $ Complex (toDouble x :+ toDouble y)` As before, import the Data.Complex module, add ` try parseComplex` before parseNumber and parseFloat in parseExpr and the line ` \| Complex (Complex Double)` to the LispVal type. ## Section 4 - Recursive Parsers: Adding lists, dotted lists, and quoted datums ### Exercise 1 These two are analogous to parseQuoted: ` parseQuasiQuoted :: Parser LispVal`\ ` parseQuasiQuoted = do`\ `` char '`' ``\ ` x <- parseExpr`\ ` return $ List [Atom "quasiquote", x]` ` parseUnQuote :: Parser LispVal`\ ` parseUnQuote = do`\ ` char ','`\ ` x <- parseExpr`\ ` return $ List [Atom "unquote", x]` ` parseUnQuoteSplicing :: Parser LispVal`\ ` parseUnQuoteSplicing = do`\ ` char ','`\ ` char '@'`\ ` x <- parseExpr`\ ` return $ List [Atom "unquote-splicing", x]` Also add ` <\|> parseQuasiQuoted`\ ` <\|> parseUnQuote`\ ` <\|> parseUnQuoteSplicing` to parseExpr. ### Exercise 2 I chose to go with Arrays as described in Data.Array and used list-array conversions for array construction. ` parseVector :: Parser LispVal`\ ` parseVector = do arrayValues <- sepBy parseExpr spaces`\ ` return $ Vector (listArray (0,(length arrayValues - 1)) arrayValues)` In order to use this, import Data.Array and add the following to the LispVal type: ` \| Vector (Array Int LispVal)` Add the following lines to parseExpr; before the parser for Lists and DottedLists. ` <\|> try (do string "#("`\ ` x <- parseVector`\ ` char ')'`\ ` return x)` ### Exercise 3 This took a fair amount of fiddling with `sepBy`, `endBy` and friends. I started by getting the `(. degenerate)` dotted list to work and then went from there. This code tolerates trailing and leading spaces. `parseAnyList :: Parser LispVal`\ `parseAnyList = do`\ ` P.char '('`\ ` optionalSpaces`\ ` head <- P.sepEndBy parseExpr spaces`\ ` tail <- (P.char '.' >> spaces >> parseExpr) <\|> return (Nil ())`\ ` optionalSpaces`\ ` P.char ')'`\ ` return $ case tail of`\ ` (Nil ()) -> List head`\ ` otherwise -> DottedList head tail` Another implementation using more advanced functions from the Parsec library. `spaces` is the one from this tutorial. `parseList :: Parser LispVal`\ `parseList = between beg end parseList1`\ ` where beg = (char '(' >> skipMany space)`\ ` end = (skipMany space >> char ')')` `parseList1 :: Parser LispVal`\ `parseList1 = do list <- sepEndBy parseExpr spaces`\ ` maybeDatum <- optionMaybe (char '.' >> spaces >> parseExpr)`\ ` return $ case maybeDatum of`\ ` Nothing -> List list`\ ` Just datum -> DottedList list datum` Alternative solution. `spaces` is the spaces from Parsec and `spaces1` is the spaces from this tutorial. `parseList :: Parser LispVal`\ `parseList = do char '(' >> spaces`\ `` head <- parseExpr `sepEndBy` spaces1 ``\ ` do char '.' >> spaces1`\ ` tail <- parseExpr`\ ` spaces >> char ')'`\ ` return $ DottedList head tail`\ ` <\|> (spaces >> char ')' >> (return $ List head))` # Chapter 3 ### Exercise 1 Here is one way of adding a few of them. `primitives :: [(String , [LispVal] -> LispVal)]`\ `primitives = [("+" , numericBinop (+)) ,`\ ` ("-" , numericBinop (-)) ,`\ ` ("" , numericBinop ()) ,`\ ` ("/" , numericBinop div) ,`\ ` ("mod" , numericBinop mod) ,`\ ` ("quotient" , numericBinop quot) ,`\ ` ("remainder" , numericBinop rem) ,`\ ` ("symbol?" , unaryOp symbolp) ,`\ ` ("string?" , unaryOp stringp) ,`\ ` ("number?" , unaryOp numberp) ,`\ ` ("bool?", unaryOp boolp) ,`\ ` ("list?" , unaryOp listp)]` `unaryOp :: (LispVal -> LispVal) -> [LispVal] -> LispVal`\ `unaryOp f [v] = f v` `symbolp, numberp, stringp, boolp, listp :: LispVal -> LispVal`\ `symbolp (Atom _) = Bool True`\ `symbolp _ = Bool False`\ `numberp (Number _) = Bool True`\ `numberp _ = Bool False`\ `stringp (String _) = Bool True`\ `stringp _ = Bool False`\ `boolp (Bool _) = Bool True`\ `boolp _ = Bool False`\ `listp (List _) = Bool True`\ `listp (DottedList _ _) = Bool False`\ `listp _ = Bool False` ### Exercise 2 `unpackNum :: LispVal -> Integer`\ `unpackNum (Number n) = n`\ `unpackNum _ = 0` ### Exercise 3 Add symbol-\>string and string-\>symbol to the list of primitives, then: `symbol2string, string2symbol :: LispVal -> LispVal`\ `symbol2string (Atom s) = String s`\ `symbol2string _ = String ""`\ `string2symbol (String s) = Atom s`\ `string2symbol _ = Atom ""` This doesn\'t deal well with bad input, which is covered later. # Chapter 5 ### Exercise 1 `eval env (List [Atom "if", pred, conseq, alt]) = do `\ ` result <- eval env pred`\ ` case result of`\ ` Bool False -> eval env alt`\ ` Bool True -> eval env conseq`\ ` _ -> throwError $ TypeMismatch "bool" pred` ### Exercise 2 Define a helper function that takes the equal/eqv function as an argument: ` eqvList :: ([LispVal] -> ThrowsError LispVal) -> [LispVal] -> ThrowsError LispVal`\ ` eqvList eqvFunc [(List arg1), (List arg2)] = return $ Bool $ (length arg1 == length arg2) && `\ ` (all eqvPair $ zip arg1 arg2)`\ ` where eqvPair (x1, x2) = case eqvFunc [x1, x2] of`\ ` Left err -> False`\ ` Right (Bool val) -> val` Now adjust the eqv clause: ` eqv listPair@[List _, List _] = eqvList eqv listPair` And add clauses for List and DottedList to the equal function: ` equal :: [LispVal] -> ThrowsError LispVal`\ ` equal listPair@[List _, List _] = eqvList equal listPair`\ ` equal [(DottedList xs x), (DottedList ys y)] = equal [List $ xs ++ [x], List $ ys ++ [y]]`\ ` equal [arg1, arg2] = do`\ ` primitiveEquals <- liftM or $ mapM (unpackEquals arg1 arg2)`\ ` [AnyUnpacker unpackNum, AnyUnpacker unpackStr, AnyUnpacker unpackBool]`\ ` eqvEquals <- eqv [arg1, arg2]`\ ` return $ Bool $ (primitiveEquals \|\| let (Bool x) = eqvEquals in x)`\ ` equal badArgList = throwError $ NumArgs 2 badArgList` ### Exercise 3 #### cond Room for improvement here! `eval (List ((Atom "cond"):cs)) = do `\ ` b <- (liftM (take 1 . dropWhile f) $ mapM condClause cs) >>= cdr `\ ` car [b] >>= eval `\ ` where condClause (List [p,b]) = do q <- eval p`\ ` case q of`\ ` Bool _ -> return $ List [q,b]`\ ` _ -> throwError $ TypeMismatch "bool" q `\ ` condClause v = throwError $ TypeMismatch "(pred body)" v `\ ` f = \(List [p,b]) -> case p of `\ ` (Bool False) -> True`\ ` _ -> False` Another approach: `eval env (List (Atom "cond" : expr : rest)) = do`\ ` eval' expr rest`\ ` where eval' (List [cond, value]) (x : xs) = do`\ ` result <- eval env cond`\ ` case result of`\ ` Bool False -> eval' x xs`\ ` Bool True -> eval env value`\ ` otherwise -> throwError $ TypeMismatch "boolean" cond`\ ` eval' (List [Atom "else", value]) [] = do`\ ` eval env value`\ ` eval' (List [cond, value]) [] = do`\ ` result <- eval env cond`\ ` case result of`\ ` Bool True -> eval env value`\ ` otherwise -> throwError $ TypeMismatch "boolean" cond` Yet another approach, piggy-backing off of the already-implemented if: `eval form@(List (Atom "cond" : clauses)) =`\ ` if null clauses`\ ` then throwError $ BadSpecialForm "no true clause in cond expression: " form`\ ` else case head clauses of`\ ` List [Atom "else", expr] -> eval expr`\ ` List [test, expr] -> eval $ List [Atom "if",`\ ` test,`\ ` expr,`\ ` List (Atom "cond" : tail clauses)]`\ ` _ -> throwError $ BadSpecialForm "ill-formed cond expression: " form` Yet another approach ` eval (List ((Atom "cond") : alts)) = cond alts` ` cond :: [LispVal] -> ThrowsError LispVal`\ ` cond ((List (Atom "else" : value : [])) : []) = eval value`\ ` cond ((List (condition : value : [])) : alts) = do`\ ` result <- eval condition`\ ` boolResult :: Bool <- unpackBool result`\ ` if boolResult then eval value`\ ` else cond alts`\ ` cond ((List a) : _) = throwError $ NumArgs 2 a`\ ` cond (a : _) = throwError $ NumArgs 2 [a]`\ ` cond _ = throwError $ Default "Not viable alternative in cond"` #### case This solution requires LispVal to have a deriving (Eq) clause, in order to use the \`elem\` function. `eval form@(List (Atom "case" : key : clauses)) =`\ ` if null clauses`\ ` then throwError $ BadSpecialForm "no true clause in case expression: " form`\ ` else case head clauses of`\ ` List (Atom "else" : exprs) -> mapM eval exprs >>= return . last`\ ` List ((List datums) : exprs) -> do`\ ` result <- eval key`\ ` equality <- mapM (\x -> eqv [result, x]) datums`\ `` if Boolean True `elem` equality ``\ ` then mapM eval exprs >>= return . last`\ ` else eval $ List (Atom "case" : key : tail clauses)`\ ` _ -> throwError $ BadSpecialForm "ill-formed case expression: " form` ### Exercise 4 Let\'s add string-length and string-ref: ` primitives = [...`\ ` ("string-length", stringLen), │`\ ` ("string-ref", stringRef),`\ ` ...]` ` stringLen :: [LispVal] -> ThrowsError LispVal`\ ` stringLen [(String s)] = Right $ Number $ fromIntegral $ length s`\ ` stringLen [notString] = throwError $ TypeMismatch "string" notString`\ ` stringLen badArgList = throwError $ NumArgs 1 badArgList` ` stringRef :: [LispVal] -> ThrowsError LispVal`\ ` stringRef [(String s), (Number k)]`\ ` \| length s < k' + 1 = throwError $ Default "Out of bound error"`\ ` \| otherwise = Right $ String $ [s !! k']`\ ` where k' = fromIntegral k`\ ` stringRef [(String s), notNum] = throwError $ TypeMismatch "number" notNum`\ ` stringRef [notString, _] = throwError $ TypeMismatch "string" notString`\ ` stringRef badArgList = throwError $ NumArgs 2 badArgList`
# Lucid Dreaming/Introduction \ ## Disclaimer When attempting some of the techniques in this book, you may have some frightening experiences, such as falling sensations or sleep paralysis. Although the authors attest these are not dangerous, you should avoid techniques that create these sensations if you would prefer not to experience them. Your own expectations will have a significant effect on your dreams. If you believe that dream characters act dull and lifelessly, they are far more likely to do so. If you believe they can be creative, original, and surprising, they are far more likely to be. Remember that the easier you think it is to dream lucidly, the easier it will be. Many of the techniques and "facts" presented on these pages are not backed up by scientific research. This is not to say that these techniques do not work, only that they may be placebos or be ineffective much of the time. ## About dreaming ```{=html} <div style="float: right; margin: 0 0 1em 1em; font-style: oblique; font-size: smaller;"> ``` !Stages of sleep\ The stages of sleep ```{=html} </div> ``` Each night, we spend about one and a half to two hours dreaming. We dream about once every 90 minutes of sleep. The time you spend in dreams becomes longer throughout the night, from about 10 minutes to around 45 minutes or slightly longer. But what happens when we sleep? There are five stages of sleep: four stages of NREM (Non-REM) sleep, also called SWS (Slow-Wave Sleep), and one stage of REM (Rapid Eye Movement) sleep. The most vivid and remembered dreams occur during REM sleep. Research has shown that a person being woken from REM sleep will account having just been in a dream roughly 80% of the time, while this percentage is 15% during non-REM sleep.[^1] One sleep cycle is roughly 90 minutes long. - (NREM 1) The first stage is a transition state between wakefulness and sleep. This is the stage in which hypnagogic imagery occurs. It usually passes into stage 2 within a few minutes. - (NREM 2) During stage 2, the body gradually shuts down, and brain waves become longer in wavelength. - (NREM 3) Stage 3 usually occurs 30 to 45 minutes after falling asleep the first time. Large, slow delta brain waves are generated. - (NREM 4) Stage 4 is often called "deep sleep" or "delta sleep". The heart beats the slowest and there is the least brain activity. It is during this stage that sleepwalking usually occurs. - After stage 4, the NREM stages reverse and move back to stage 2, and then into REM sleep. - (REM) During REM sleep, some parts of the brain are nearly as active as while awake. In this stage, your eyes flicker rapidly (hence the acronym Rapid Eye Movement). Your body is paralyzed, preventing the body from acting out dreams.[^2] After the REM state, you sometimes wake briefly. This is usually forgotten by the time you wake up in the morning. If you don\'t wake up, you go to stage 2. I never dream anyway. Actually, everyone has dreams --- but some people simply don't remember them. In the next chapter, you will find out how to improve your dream recall. Why do we dream? What do dreams mean? These questions are outside the scope of this book, but you can find several hypotheses in the Wikipedia article on dream interpretation. ## About lucid dreaming Lucid dreaming is simply being aware that you are dreaming. With enough experience, you can increase control over your dreams --- anything from flying to creating people and places, and even changing into animals. Having a lucid dream is like being the director of your own movie! A passage from the fantasy novel Harry Potter and the Deathly Hallows (chapter at King\'s Cross) that may explain what this looks like: > For the first time, he wished he were clothed. Barely had the wish > formed in his head than robes appeared a short distance away. Lucid dreams have been scientifically proven to exist. Stephen LaBerge of The Lucidity Institute used a special machine to track eye movements during a dream (these are linked to your eye movements within the dream). He asked lucid dreamers to point their eyes left and right in quick succession once they became \"conscious\" in their dreams, and this movement was recorded on the machine. For more information on this and other experiments, read Exploring the World of Lucid Dreaming (ISBN in Further Reading). There are plenty of reasons you might want to dream lucidly: - For fun! Just flying in a lucid dream is an exhilarating feeling. Lucid dreams are generally far more intense and vivid than most non-lucid dreams. You can use a lucid dream to wind down after a long day. - Transforming into animals or getting superpowers is a unique experience that is hard to get any other way. - If you are particularly interested in dreams --- either spiritually or psychologically --- trying lucid dreaming could help you in your research. - If you\'re writing fiction or even creating a world for a computer game, lucid dreaming can help you visualize it. You could ask your characters how they feel about something or what they think will happen. - Some people compose music in their lucid dreams. - Lucid dreams can be realistic enough to rehearse a speech or musical performance. - You can relive previous dreams or experiences. - They can help in dream interpretation and communicating with your subconscious. I can't control my dreams. This is very rarely actually the case (though sometimes it is in nightmares). Usually it is just your memory which treats you as though it were beyond your control. If you become lucid in a dream where you have a body, you will almost always be able to control your body. However, you might not manage to do anything else. Don\'t worry, though --- most people have no problem with jumping very high or flying in a lucid dream! On the other hand, parts of your brain are less active while dreaming, which can lead to dream/trance logic and sometimes choices you will later regret. For example, you might choose to continue your lucid dream, although you know that once you wake you will only remember half of it. Once you wake up, you may wish that you had stopped your dream. Another example is of somebody who dreamt they were sitting next to Mother Theresa. They wondered if they might be dreaming, thinking isn't Mother Theresa dead? They then concluded that she was obviously right next to them and therefore alive, and that it wasn't a dream! Are lucid dreams related to psi phenomena? There are differing views on this. Some people claim to have organized shared dreams or precognitive dreams through lucid dreaming. Others say these are simply created in the brain like any other dream, something like self-hypnosis. How long does it take to learn how to dream lucidly? This completely depends on the person and circumstances. Some people have a lucid dream after just a few nights of learning about it, while for others, it may take months! If you don\'t get enough sleep or feel too stressed after work to regularly practice induction techniques, then it may take a long time, especially if you expect it to. It will also depend on how much effort you put in. However, everybody has the ability to dream lucidly. I think I do this naturally. Does this happen? It is quite rare to have regular lucid dreams naturally, although most people have had a lucid dream at some point in their lives. If you want to increase the frequency of your lucid dreams, carry on reading through the book; otherwise, skip to the Using section to get some ideas for your dreams. I had \[a dream\], was I lucid? In general, a lucid dream is defined as a dream in which you know you are dreaming at some point, regardless of anything else. Even if you were lucid one second but lost your lucidity, it is still technically a lucid dream. However, this can be a little misleading. Sometimes you dream that you fall asleep and have a lucid dream! This is often thought of as a sign that you will have a proper lucid dream soon, as your mind is thinking a lot about lucid dreams. Try using this table: +-----------------------------------+-----------------------------------+ \| Signs you were lucid \| Signs you weren\'t lucid \| +===================================+===================================+ \| - Doing a reality check which \| - Dreaming that you were \| \| gave a positive result \| dreaming \| \| - Attempting to stabilize the \| - Having an unusually poor \| \| dream (see the \| recall for that dream after \| \| Using \| - Not recognizing illogical \| \| chapter) \| parts of the dream as a dream \| \| - Attempting to fly, walk \| - Attempting to fly, walk \| \| through mirrors, etc. \| through mirrors, etc. without \| \| immediately after realizing \| success \| \| you are dreaming \| - Treating dream characters as \| \| - Waking up as soon as you \| you would real people\* \| \| realize that you are dreaming \| \| \| - Remarks to dream characters \| \| \| that you are dreaming \| \| +-----------------------------------+-----------------------------------+ \* However, some people may have lucid dreams and deliberately choose to treat dream characters as if they were real. In fact, it can be intriguing to have real conversations with dream characters, such as physics or philosophy discussions - you may discover they know more than you do! ## Possible dangers of lucid dreaming There is no current evidence of lucid dreaming being abnormal or unhealthy in any way. However, there may be some more or less minor side effects associated with having lucid dreams. Please don't let this scare you away from trying this; rather, remember that with dreams you are dealing with your own subconscious mind and recklessness is not recommended. ### Alienation Most people have never even heard of lucid dreaming, much fewer ever experienced it. Some people are also less than open-minded and receptive to new ideas. Don't be surprised if someone considers this whole phenomenon "weird" or "crazy" (which it is not). Don't preach, either; you don\'t have to convince anybody. Often people who spontaneously lucid dream, especially children, may find it surprising that not everyone does. They may even start thinking that they are the only people in the world who have lucid dreams. If they're worried, the best support is to let them know that they're not alone. ### Dissociation Lucid dreaming may weaken the borders between waking and dreaming, the conscious and subconscious mind, reality and fantasy. This might lead to problems of a dissociative nature. Probably the most common form of dissociation involves having problems distinguishing your waking memories from dream memories. Everyone who recalls at least one dream will have to sort out their dreams from reality in the morning. This can really be a problem for those who have previously had zero recall and, due to lucid dreaming, have had a major uptick in recall. Now, suddenly, they have all these excess, illogical memories to sort out. This is unlikely to be a major problem, but may be a big annoyance. An example is when you have actually misplaced an item, and \"find it\" in a dream. If you cannot distinguish dream from reality you will now think you know where that item is, perhaps even placed it where you felt sure to find it later, but when you awake it will not be there. However, there are signs that you should watch for which indicate a larger problem may be developing. Lucid dreaming in itself should not cause these to appear in a waking state: - Ability to ignore extreme pain or what would normally cause extreme pain - Absorption in a computer game, television program or movie - Remembering the past so vividly one seems to be reliving it - Finding evidence of having done things one can't remember doing - Not remembering important events in one's life - Being in a familiar place but finding it unfamiliar - Seeing oneself as if looking at another person - Other people and objects do not seem real - Looking at the world through a fog or haze - Not recognizing friends or family members - Finding unfamiliar things among one's belongings - Finding oneself in a place but unaware of how one got there - Finding oneself dressed in clothes one doesn't remember putting on If this has happened, and there is no other cause (e.g. drugs), take a break from lucid dreaming for a while. In fact, take a break from anything fictional for a while, at least until symptoms stop. In addition, you may consider avoiding experimentation with lucid dreaming if you have a mental condition that will alter your perception of reality, eg. Schizophrenia, Hallucinations, Dementia. ### False awakenings One of the advantages of having lucid dreams is being able to change a dream or wake up if things are not turning out as planned. A false awakening is when you seem to have woken up but are actually still dreaming. For example, you may find yourself waking up in your room. But once there, new things will start happening---for example, someone might visit, or you might wander outside because of an odd noise, or there might be objects all over the place. There are no such things as loops of awakenings. You can simply shock your body awake by applying a stimulus in your dream. It\'s a good idea to get in the habit of doing a reality check just after waking up so that you\'ll realize when this happens and become lucid. When this happens repeatedly in the same night, it can be very tiring and often frightening. Not only can the belief of being fully awake in your room while being exposed to unusual situations be scary, but you also may start fearing you won\'t be able to actually wake up. And, depending on the content of the dream, since all your dreams tend to start in your room, you may fear what could happen once you actually do wake up. But this is not a very common situation. Once you are lucid, it is usually easier to wake up or lose the dream than it is to keep dreaming. ### Controversial: Accidentally encountering "spiritual" entities This depends on your worldview. If you believe that dreams are a creation of your brain and nothing more, you don't need to worry about spirits or anything similar. If you want to be on the safe side, treating objects in your dream decently and politely won't do you any harm. The book \"The Art of Dreaming\" by Carlos Castaneda has a lot to say on this subject. (See Further Reading) ### Controversial: Creating bad habits or becoming a control freak When lucid dreaming, you have the option to control the dream world in ways that are impossible in the waking world. You can, for example, make objects appear or disappear, or make people act according to your will. Some people believe this may lead your subconscious to desire this kind of control in the waking world, where it's highly inappropriate. Also, you might be tempted to apply dream-world solutions to waking-life problems instead of actually facing them; for example, just willing bad things to go away or escaping or destroying them by superpowers. Again, this is probably more of a problem if you are not mentally stable at the outset of your dreaming process. ### Controversial: Exhaustion Some people believe that experiencing many artificially induced lucid dreams often enough can be very exhausting. The main reason for this phenomenon is the result of the lucid dreams expanding the length of time between REM states. With fewer REMs per night, this state in which you experience actual sleep and your body recovers becomes infrequent enough to become a problem. This is just as exhausting as if you were to wake up every twenty or thirty minutes and watch TV. The effect is dependent on how often your brain attempts to lucidly dream per night. If you enter into a routine of attempting to lucidly dream, you may cause recursive lucid dreams that occur at each state change. ### Controversial: Inability to stop If you have trained your mind to the point where it can step over the boundary without conscious effort, you might find it difficult to stop. Do not become alarmed if you have trouble stopping the process of lucid dreaming, it is possible to get out of the habit. As long as you truly expect to stop having lucid dreams regularly, you will. You just need to stop any further attempts to lucid dream, and within a few months the lucid dreaming will go away by itself. Remember; do not be alarmed if, even with your attempts to stop, you experience further lucid dreams. It might take a while to break the habit. If you have real concerns, it may be advisable to talk with your doctor or therapist regarding appropriate treatment, including medication. ## Similar techniques I can do astral projection, should I learn how to dream lucidly? Possibly not. If you often enter a "dream world" after having the experience of leaving your body, that is basically the same as the method called Wake-Initiation of Lucid Dreams. Keep in mind that many people believe that "astral projection" or "out-of-body experiences" are actually lucid dreams. Whether these are real psi phenomena or the creative product of your dreaming mind, learning to dream lucidly will expand the variety of your experiences. If this is so similar, why learn lucid dreaming and not astral projection? Here are some reasons: - Lucid dreaming is something that everybody can understand. In fact, most people have already had a lucid dream. No single theory about astral projection is accepted even in the astral projection community. - If you are prepared to spend money, there are some gadgets that can help induce lucid dreams. They usually emit light or sound signals shortly after the REM state is detected. Hypnosis tapes usually focus more on self-improvement and you cannot decide what to do with your hypnotic trance. - If you don't believe in psi phenomena, you will likely be much more comfortable reading books about lucid dreaming than those on astral projection. If you have to keep stopping and thinking \"but that\'s not possible\", there\'s always the danger that your feelings of skepticism will affect the way you think about lucid dreaming and make it much harder for you to do. - You would be sleeping anyway, so it doesn\'t take up waking time. - You\'ll be able to use this Wikibook to your advantage! ## References ```{=html} <references/> ``` es:Sueño lúcido/Introducción it:Sogno lucido/Introduzione pl:Świadome_śnienie/Wstęp [^1]: Arno F. Wittig. Schaum\'s outline of theory and problems of introduction to psychology. McGraw-Hill, 1977. Retrieved from Google Books on September 23, 2009. [^2]: Rochelle Merilien. Sleep Paralysis. Retrieved September 21, 2009 from 1
# Lucid Dreaming/Using ## Dream stabilization Once you are able to dream lucidly, you may find that it is difficult to stay in the dream; for example, you may wake instantly or the dream may start "fading" which is characterized by loss or degradation of any of the senses, especially vision. Alternatively, a new lucid dreamer could easily forget that they are in a dream, as a result of the shock of the sensation. Don\'t worry if you wake immediately after becoming lucid. As you gain more experience of becoming lucid, it will come as less of a shock and you'll be less likely to wake up. Make sure you do a reality check to be sure you're not still dreaming. As you gain more experience, you will have an easier time identifying when and remembering that you are dreaming. You can avoid more gradual fadings by stimulating your senses. This means listening for sounds, feeling around with your hands, and paying attention to what you see and smell. The idea here is to load your senses with stimulation from the dream so that your senses cannot shift to the real world. If you close your eyes, you are removing a great deal of sensory information and might wake up. Staring at a single point can cause effectively the same problem if you stop seeing everything else in your peripheral vision, or don\'t see enough movement. If you hear something loud in real life and are hearing nothing in the dream, your senses may shift to the real world, causing you to wake up. Ideally you should be able to use the techniques below to stabilize your dream before it starts to fade (or "black out"). As always, prevention is better than treatment - and the more stable and vivid your dreams are, the more enjoyable they will be. However, if that doesn\'t work you may be able to use stabilization techniques to stop the fading; the spinning technique is probably the most effective in this case. If you still can't stabilize your dream, you may decide to try and wake up with the aim of remembering your dream as accurately as possible while its still fresh in your mind. ### Hand Touching Rub your hands together and concentrate on the rubbing. You should feel the friction and the heat of your hands. If you can concentrate on the feelings that this action generates, your dream is likely to stabilize and become more vivid and detailed. You can also keep one hand on your arm while exploring the dream for a constant sense of stimulation. This technique is most effective when used in conjunction with the "Slowing it down" technique, by staring at your hands while rubbing them together. ### Spinning You spin around in your dream much as you would if you suddenly want to feel dizzy in real life. The sensation of movement is the key here to stabilizing the dream. Many people report success with this technique, but it also tends to cause a complete change of your dream scene (see Changing the dream environment below). If the dream scene disappears completely (e.g., becomes black), it is necessary to visualize the dreamscape to return to the dream. ### Slowing it down Some people like to stabilize the dream by "stopping to smell the roses" and slowly staring at a dream object until it becomes clear. The dreamer would then look around elsewhere, noticing how detailed everything is, thereby stimulating the visual portion of the dream. However, others find this can cause their lucid dream to end. If you focus on one object for too long to the exclusion of everything else, you will likely wake up or lose the dream. It works best to pay attention to everything in your vision, including your peripheral vision, not just the center of the object you\'re staring at. If staring at a single object doesn\'t work for you, try to let your eyes wander around instead. ### Touching your dream If you feel that your dream is too abstract and fear that it might be fading, you can prevent this by grabbing hold of a solid object in your dream and focus on how real the sensation is. A good tip is to find something you know is stuck, for instance a table nailed to the ground, and pull it with all your muscular power (no supernatural powers!), and you should feel how solid it is. The idea is that you convince yourself that the dream is solid and real --- through tactile stimulation --- and nothing abstract. ### Regaining waking memory or skills This is also likely to enhance your degree of lucidity. Try to remember facts from your waking life, such as your phone number, address, etc., or do some simple math. Or, start reciting the lyrics to your favorite song. Or perhaps try some sports practice you know well --- this all depends on which senses / methods of thought process you tend to rely on most in your waking life. ### Dream Guide Summon a DC (Dream character) that you expect to Guide you through the dream. Summoning is easier if you always expect this Guide to be there in a dream. The Guide is useful for escaping scary or unpredicted environments (\"whooshing\" you away, killing or unsummoning the threat, reminding you that you are in control.). Imagine this Guide as powerful, knowledgeable, and protective over you. Guides can also walk you through summoning, flying, shapeshifting, etc. and be useful for learning and controlling your dreams. ### False awakening A couple of the users on the ld4all.com forums have had success with creating a false awakening to stabilize a dream. If the above techniques are failing and you find your dream still fading, and you really want to continue your lucid dream, do the following: 1. Expect to have a false awakening. 2. When you think you wake up, perform a reality check. You will either have a false awakening, reality check, and then end up with an even more vivid lucid dream, or will really wake up, perform a reality check, and realize that you just woke up (bad luck!). The most important part of this is the reality check. This is what will continue your lucid dream. You should be performing reality checks when you wake up. If you plan to induce false awakenings in order to stabilize a dream, the reality check that you perform as you wake up is as important as the one that got you lucid, if not more. Perform every check in the book until you are positively, absolutely, and completely sure that you aren't dreaming. A series of 10 reality checks is more likely to produce dream results in a dream, especially if you are expecting dream results. This technique is for those who are desperate! If you have had a good experience with this technique, please go to the talk page and post your experiences, as there have not been many anecdotes of it working yet. ```{=html} <div style="text-align: right; font-size: small"> ``` top ```{=html} </div> ``` ## Recovering from lost visuals There are a few things you can try to do if you lose your vision. Most of these are less likely to help prolong your dream than the above techniques. You can also try these if you have just woken up and are lying in your bed. You may be able to return to your dream. ### Autosuggestion You can repeat over and over a phrase similar to "I can see my dream," or otherwise enforce in your mind that you can see a dreamscape. (See Autosuggestion) ### Visualising You can visualise the scene as it would be if you could see it. You could take this as an opportunity to change the dreamscape by visualising a different environment from the previous one in the dream. This can be made easier by spinning as you visualize. (See Changing the dream environment below) ## Altering the dream ### Changing the dream environment You can change the dreamscape by simply visualizing a different environment. Stephen LaBerge, author of Exploring the World of Lucid Dreaming, suggests closing your eyes, spinning around, and visualizing a new location. Alan Worsley, a famous lucid dreamer, describes another technique of summoning a television and remote to switched dreamscapes. By simply "changing the channel" on the remote, imagine your surroundings switching to your desired location, as though you were switching through various television programs. In both of these methods, details are key. The more details you provide for your next dreamscape, the easier it will be to get there. For example, if you wanted go to the Superbowl in your dreams, you might simply state: : "I want to be at the Superbowl." But this statement could be improved by adding details: : \"I want be in the endzone seats, drinking a Coke, and wearing my favorite player\'s jersey at the Super Bowl.\" ### Summoning objects into your dream At some point in your lucid dreaming experience, you\'ll probably want to handle various objects, or talk with certain people. Both of these needs can be fulfilled by using your mind, and the power of suggestion. There is no set way to \"make\" things in the dream world; in fact, many lucid dreamers devise their own methods through experimentation. However, here are some of the more common \"summoning\" techniques: - Try reaching for objects that are not within your field of vision. For example, think to yourself: "When I reach into my pocket, there will be a green box of mints." Then, attempt to actually take a green box of mints out of your pocket. Other variations of this include reaching behind you for an object, or reaching through a mirror in hopes of getting a hold of what you want. - To summon a person, you might say to yourself: "When I turn around, \[person\'s name\] will be standing in front of me," or "When I walk through this mirror, I will see \[person\'s name\]," or "In a few moments, \[person\'s name\] will walk through that door (or around that corner)." - More experienced lucid dreamers can try making the object materialize right before their eyes. This will require a fair amount of concentration. Here is an example of this process:\ : I am lucid dreaming in my backyard, and it\'s currently night. Now, I don\'t like the dark in my lucid dreams because I\'m more likely to wake up, and I fear there are monsters lurking around every corner. So, I want to make the sun appear so that it\'ll be daytime. Focusing on the horizon, I visualize the sun rising above it.\ : At first nothing happens, but I continue focusing and\...yes! There\'s some light filtering over the horizon! And now the sun is rising to the sky and it settles there; so far, so good. But wait\...the sky is still black. Peering at bit closer at the sun, I can just make out a faint ring of blue sky encircling it. Lifting my hand towards it I shout, \"Blue!\". The blue ring quickly spreads across the sky, creating the full daytime effect."\ - Some dreamers may have success by closing their eyes and imagining the desired object in front of them once when they open their eyes . - Try using mechanical devices within the dream, such as a nearby lightswitch or button, to summon objects or people. (i.e. \"When I flip this switch/press this button, X will appear.\") - Convince yourself you have magical powers (or scientific). Then, use them to summon objects, shapeshift, etc. This can help you believe the creation of objects more easily. - (This one is dumb, but it works.) Begin singing Friend Like Me, and summon stuff to the beat. They may disappear after you finish singing, or start dancing, but hey, it\'s pretty darn fun. Remember, in the dream world, your expectations shape your surroundings. If you think a big, scary monster is going to step out of the shadows and attack you\...well, a big, scary monster probably is going to step out of the shadows and attack you. So, don\'t be a victim; take control of your thoughts and use them to your advantage. ```{=html} <div style="text-align: right; font-size: small"> ``` top ```{=html} </div> ``` ## What you can do This final section should see you off with a few ideas of what to do in a dream. It is advised to have a clear purpose for your lucid dreams whenever you go to sleep. In other words, every night you consider what you want to do when you have a lucid dream, and select one thing, or perhaps two or three if you are skilled. Avoid this: : \"What am I gonna do what am I gonna do? I wanna fly, walk through walls, eat until my stomach explodes, spy on my neighbours, drive in a car real fast, woooeeey I\'m gonna . . .\" You will either end up doing none of these things in your dream or getting overexcited and waking up. Now that that's clear, here's a list of possible things you could do, ordered in difficulty. Remember that you might find some things unusually hard (or easy) compared to most lucid dreamers, this is perfectly normal! This is a very rough guide --- if you've managed something in the Easy section, don\'t be scared to try for something from the Medium section. ### Easy - Fly : Most people enjoy flying around in dreams. There are different styles of flight that people use, each with a varied level of success for each individual. Methods such as "swimming through the air", "Superman style" (one arm outstretched), "Neo style" (both arms at your side), and "Airplane style" (both arms out) ,\"eagle style\" (gliding through the air currents, using your fingered wings to navigate altitudes) are often used. There are a few methods of getting up into the air, such as simply jumping (you can jump really high in dreams if you believe it) or imagining a great force pushing you from your feet or walking up on air as though it is a staircase. Some people summon jetpacks and slip them on to fly. Be creative and dream up your own methods. - Explore your dream world : Be warned, you are quite likely to forget you are dreaming when exploring! Doing reality checks often and muttering to yourself about how real everything seems can help to avoid this. You can also ask a dream character to tag along with you and remind you when you forget that you're dreaming. - Walk through a mirror or wall : You can pass through dream objects such as walls, glass, trees, and everything else. Confidence is really the key here. Some variations on going through stuff can be going in slowly, wiggling your finger in first, or running quickly into the object and telling yourself you would go through it. Some people particularly like to go through mirrors because of the unpredictable effects this action produces. However, if you tell yourself you will end up at a certain location before passing through a mirror, you can change the dream scene quickly. Be warned, some people experience nothing and wake up after passing through. You may want to hold your arm to keep yourself in the dream. - Look at the sky : People often report amazing skies in lucid dreams. You can also shout colors at it and paint some sunrises. - Show off to your friends ("Hey guys; I can go through this wall!") - Do plenty of sports (trampolining, skiing, swimming, dancing, etc.) - Use various power such as Telekinesis and magic (a shortcut if you are having problems would be to summon a magic wand/staff or other device) - Try to read a book that you have never read and remember the content - Try to browse the Internet and visit sites that you\'ve never visited - Use things that you have never used - Last but not least: Edit Wikipedia/Wikibooks articles (see question 106 of the Wikipediholic Test) and see if the changes remain when you awake! ### Medium - Eat until you're near bursting! - Teleport - Create some dream characters (possibly from a book or film) - Try to find your spirit guide - Experiments (in fact, researchers will often want people of various skills) - Body swapping/possession (where you enter a different body) - Morph - Take some drugs (this is more realistic if you've done so in real life) : Many people have also experienced realistic effects when trying drugs in dreams that they have never taken in real life. - Drive a vehicle (This is especially fun if you haven\'t ever driven in real life) - Fight : Nobody can tell you what you should and should not do in your dreams; the choice remains up to you. - Use weapons : It is usually more interesting to use melee weapons (knives, swords, brass knuckles) than projectile weapons. Machine guns and pistols often run out of ammo and summoning it can be difficult. Misfires and jamming is also common. (Your subconscious expectations will shape your dreamscape in all manner of ways, If you believe it is hard to accomplish, if you believe it will jam or misfire, it will. I have had no issues with weaponry such as firearms in my dreams what-so-ever, take this \"advice\" lightly.) However this can be overcome by using Directed Energy Weapons (Lasers, Plasma/pulse rifles), or weapons that can\'t jam (bows, simple firearms like muskets and so on). - \"Beat up\" your enemies ### Hard - Have sex : The excitement, or closing your eyes, can cause you to wake up. An additional reason for waking up may be fixing your eyes on your partner, as holding a gaze for long is also known to cause waking up. Also your dream partner has a strange way of transforming in the midst of ecstasy. Finding a sex partner isn\'t very hard, it\'s keeping them that is difficult. That is why it is best to not panic when they are transforming and accept them for what your subconscious brings you. - More morphing like 360 degree vision, sonar vision, etc. - Create false memories, etc. False memories can be made by having a lucid dream, but scripting it so you will think it is real, e.g. you think what happened in your dream happened in real life. This is hard because you will have to forget it is a dream while staying lucid (knowing it is a dream). - Compose music or poems (or request them from your subconscious) - Build a fantasy dream world! (some people build a dream world naturally) - Lucid Crossroads - Astral Pulse Island - H.P. Lovecraft\'s Dreamlands - Have precognition (your subconscious can be very good at predicting the future with relationships and career) - Experience death. This could be a very harsh experience, and depending on your religious or philosophical beliefs may summon you into a different world or nothingness. - Ask the dream to show you your worst fears/deepest traumas/etc. (be prepared for some bad stuff to surface) - Build/use impossible objects, such as hypercubes, Klein bottles, etc. - Rewind time ```{=html} <div style="text-align: right; font-size: small"> ``` top ```{=html} </div> ``` ## Conclusion With all the techniques in this book, you may feel overwhelmed and uncertain of what to do next. Don\'t worry --- just choose a few techniques to "map your way to lucidity", decide on a few things you will want to do from this page, and start! If you are still unsure of what to do, don't worry --- you might happen to have a lucid dream tonight! If you are beginning to feel a compulsive thirst for more information about dreams, head over to the Further Reading section for the sites to satisfy your cravings. Remember to come back occasionally and help make the wikibook grow! ```{=html} <div style="text-align: right; font-size: small"> ``` top ```{=html} </div> ``` es:Sueño lúcido/Uso it:Sogno lucido/Uso
# Lucid Dreaming/Glossary CAT :See Cycle Adjustment Technique.\ Cycle Adjustment Technique : Adjusting your sleep cycles to increase the likelihood of having a lucid dream. DC :See Dream character.\ DILD :See Dream-Initiated Lucid Dream.\ Dream character : Any character inside your dream. Some people believe they are real people or spirit guides, others that they\'re just products of the dreaming mind. Dream-Initiated Lucid Dream : A lucid dream that begins during a \"normal\", non-lucid dream. Dream recall : The ability to remember details of one\'s dreams. Dream Result : Result from a reality check that indicates that one is dreaming. Ex: Breathing through your nose while pinching your nostrils. Dreamscape : The landscape and scenery of one\'s dreams. Hypnagogic imagery : The images, sounds, etc. that you perceive as you fall asleep. Not to be confused with phosphenes. EILD :See Erotically induced lucid dream\ Erotically induced lucid dream : A lucid dream with sexual activity. They may trigger a real orgasm, a phenomenon know as nocturnal emission or wet dream. HI :See Hypnagogic imagery.\ LD :See Lucid dream.\ LILD :See Lucid Induction of Lucid Dreams.\ Lucid dream : A dream in which you are aware that you are dreaming. Lucid Induction of Lucid Dreams : The technique in which you do something in a lucid dream that theoretically will remind you that you\'re dreaming in your next dream. MILD :See Mnemonic Induction of Lucid Dreams.\ Mnemonic Induction of Lucid Dreams : The technique in which you mentally repeat to yourself, as you fall asleep, your future intention to realize that you\'re dreaming. Named Subconscious Technique : (See \"Getting more help with MILD from your subconscious\", in the forum links box in the MILD section.) This technique is a useful aid to the MILD and autosuggestion techniques where the dreamer actively engages his or her subconscious for dream results. NST :See Named Subconscious Technique.\ Oneironaut : A skilled lucid dreamer. Phosphenes : Patches of colour (usually red or blue) that you can constantly see while your eyes are closed. Rapid Eye Movement : The stage of the sleep cycle that your most vivid dreams occur in. RC :See Reality check.\ Reality check : A simple and quick method of determining if one is dreaming. Ex: Breathing with your nose shut, faulty light switches, etc. Real-life result : A reality check result which indicates one is may not be dreaming. Ex: Being unable to will oneself to fly. REM :See Rapid Eye Movement.\ Sleep paralysis (SP) : The body\'s natural phenomenon of paralyzing the limbs of the body while asleep. This may be experienced consciously, either by accident or during the WILD technique. VILD :See Visual Induction of Lucid Dreams.\ Visual Induction of Lucid Dreams : The technique in which you incubate a dream that reminds you to do a reality check and become lucid. Vivid dream (VD) : A dream with a notably higher level of detail. Wake-Back-To-Bed : The technique in which you wake up for a bit after a few hours of sleep and go back to sleep again. Usually used in combination with other techniques. Wake-Initiated Lucid Dream : A lucid dream triggered by consciously falling asleep. WBTB :See Wake-Back-To-Bed.\ WILD :See Wake-Initiated Lucid Dream.
# Tcl Programming/Introduction ### Introduction #### So what is Tcl? The name Tcl is derived from \"Tool Command Language\" and is pronounced \"tickle\". Tcl is a radically simple open-source interpreted programming language that provides common facilities such as variables, procedures, and control structures as well as many useful features that are not found in any other major language. Tcl runs on almost all modern operating systems such as Unix, Macintosh, and Windows (including Windows Mobile). While Tcl is flexible enough to be used in almost any application imaginable, it does excel in a few key areas, including: automated interaction with external programs, embedding as a library into application programs, language design, and general scripting. Tcl was created in 1988 by John Ousterhout and is distributed under a BSD style license (which allows you everything GPL does, plus closing your source code). The current stable version, in February 2008, is 8.5.1 (8.4.18 in the older 8.4 branch). The first major GUI extension that works with Tcl is Tk, a toolkit that aims to rapid GUI development. That is why Tcl is now more commonly called Tcl/Tk. The language features far-reaching introspection, and the syntax, while simple, is very different from the Fortran/Algol/C++/Java world. Although Tcl is a string based language there are quite a few object-oriented extensions for it like Snit, incr Tcl, and XOTcl to name a few. Tcl was originally developed as a reusable command language for experimental computer aided design (CAD) tools. The interpreter is implemented as a C library that could be linked into any application. It is very easy to add new functions to the Tcl interpreter, so it is an ideal reusable \"macro language\" that can be integrated into many applications. However, Tcl is a programming language in its own right, which can be roughly described as a cross-breed between - LISP/Scheme (mainly for its tail-recursion capabilities), - C (control structure keywords, expr syntax) and - Unix shells (but with more powerful structuring). #### One language, many styles Although a language where \"everything is a command\" appears like it must be \"imperative\" and \"procedural\", the flexibility of Tcl allows one to use functional or object-oriented styles of programming very easily. See \"Tcl examples\" below for ideas what one can do. The traditional, \"procedural\" approach would be ``` tcl proc mean list { set sum 0. foreach element $list {set sum [expr {$sum + $element}]} return [expr {$sum / [llength $list]}] } ``` Here is yet another style (not very fast on long lists, but depends on nothing but Tcl). It works by building up an expression, where the elements of the lists are joined with a plus sign, and then evaluating that: ``` tcl proc mean list {expr double([join $list +])/[llength $list]} ``` From Tcl 8.5, with math operators exposed as commands, and the expand operator, this style is better: ``` tcl proc mean list {expr {[tcl::mathop::+ {}$list]/double([llength $list])}} ``` or, if you have imported the tcl::mathop operators, just ``` tcl proc mean list {expr {[+ {}$list]/double([llength $list])}} ``` Note that all of the above are valid stand alone Tcl scripts. It is also very easy to implement other programming languages (be they (reverse) polish notation, or whatever) in Tcl for experimenting. One might call Tcl a \"CS Lab\". For instance, here\'s how to compute the average of a list of numbers in Tcl (after first writing somewhat more Tcl to implement a J-like functional language - see Tacit programming in examples): ``` tcl Def mean = fork /. sum llength ``` or, one could implement a RPN language similar to FORTH or Postscript and write: ``` tcl : mean dup sum swap size double / ; ``` A more practical aspect is that Tcl is very open for \"language-oriented programming\" - when solving a problem, specify a (little) language which most simply describes and solves that problem - then go implement that language\... #### Why should I use Tcl? Good question. The general recommendation is: \"Use the best tool for the job\". A good craftsman has a good set of tools, and knows how to use them best. Tcl is a competitor to other scripting languages like awk, Perl, Python, PHP, Visual Basic, Lua, Ruby, and whatever else will come along. Each of these has strengths and weaknesses, and when some are similar in suitability, it finally becomes a matter of taste. Points in favour of Tcl are: - simplest syntax (which can be easily extended) - cross-platform availability: Mac, Unix, Windows, \... - strong internationalization support: everything is a Unicode string - robust, well-tested code base - the Tk GUI toolkit speaks Tcl natively - BSD license, which allows open-source use like GPL, as well as closed-source - a very helpful community, reachable via newsgroup, Wiki, or chat :) Tcl is not the best solution for every problem. It is however a valuable experience to find out what is possible with Tcl. #### Example: a tiny web server Before spoon-feeding the bits and pieces of Tcl, a slightly longer example might be appropriate, just so you get the feeling how it looks. The following is, in 41 lines of code, a complete little web server that serves static content (HTML pages, images), but also provides a subset of CGI functionality: if an URL ends with .tcl, a Tcl interpreter is called with it, and the results (a dynamically generated HTML page) served. Note that no extension package was needed - Tcl can, with the socket command, do such tasks already pretty nicely. A socket is a channel that can be written to with puts. The fcopy copies asynchronously (in the background) from one channel to another, where the source is either a process pipe (the \"exec tclsh\" part) or an open file. This server was tested to work pretty well even on 200MHz Windows 95 over a 56k modem, and serving several clients concurrently. Also, because of the brevity of the code, this is an educational example for how (part of) HTTP works. ``` tcl # DustMotePlus - with a subset of CGI support set root c:/html set default index.htm set port 80 set encoding iso8859-1 proc bgerror msg {puts stdout "bgerror: $msg\n$::errorInfo"} proc answer {sock host2 port2} { fileevent $sock readable [list serve $sock] } proc serve sock { fconfigure $sock -blocking 0 gets $sock line if {[fblocked $sock]} { return } fileevent $sock readable "" set tail / regexp {(/[^ ?])(\?[^ ])?} $line -> tail args if {[string match / $tail]} { append tail $::default } set name [string map {%20 " " .. NOTALLOWED} $::root$tail] if {[file readable $name]} { puts $sock "HTTP/1.0 200 OK" if {[file extension $name] eq ".tcl"} { set ::env(QUERY_STRING) [string range $args 1 end] set name [list \|tclsh $name] } else { puts $sock "Content-Type: text/html;charset=$::encoding\n" } set inchan [open $name] fconfigure $inchan -translation binary fconfigure $sock -translation binary fcopy $inchan $sock -command [list done $inchan $sock] } else { puts $sock "HTTP/1.0 404 Not found\n" close $sock } } proc done {file sock bytes {msg {}}} { close $file close $sock } socket -server answer $port puts "Server ready..." vwait forever ``` And here\'s a little \"CGI\" script I tested it with (save as time.tcl): ``` tcl # time.tcl - tiny CGI script. if {![info exists env(QUERY_STRING)]} { set env(QUERY_STRING) "" } puts "Content-type: text/html\n" puts "<html><head><title>Tiny CGI time server</title></head> <body><h1>Time server</h1> Time now is: [clock format [clock seconds]] <br> Query was: $env(QUERY_STRING) <hr> <a href=index.htm>Index</a> </body></html>" ``` #### Where to get Tcl/Tk On most Linux systems, Tcl/Tk is already installed. You can find out by typing tclsh* at a console prompt (xterm or such). If a \"%\" prompt appears, you\'re already set. Just to make sure, type info pa at the % prompt to see the patchlevel (e.g. 8.4.9) and info na to see where the executable is located in the file system. Tcl is an open source project. The sources are available from <http://tcl.sourceforge.net/> if you want to build it yourself. For all major platforms, you can download a binary ActiveTcl distribution from ActiveState. Besides Tcl and Tk, this also contains many popular extensions - it\'s called the canonical \"Batteries Included\" distribution. Alternatively, you can get Tclkit: a Tcl/Tk installation wrapped in a single file, which you don\'t need to unwrap. When run, the file mounts itself as a virtual file system, allowing access to all its parts. January 2006, saw the release of a new and promising one-file vfs distribution of Tcl; eTcl. Free binaries for Linux, Windows, and Windows Mobile 2003 can be downloaded from <http://www.evolane.com/software/etcl/index.html> . Especially on PocketPCs, this provides several features that have so far been missing from other ports: sockets, window \"retreat\", and can be extended by providing a startup script, and by installing pure-Tcl libraries. #### First steps To see whether your installation works, you might save the following text to a file hello.tcl and run it (type tclsh hello.tcl at a console on Linux, double-click on Windows): ``` tcl package require Tk pack [label .l -text "Hello world!"] ``` It should bring up a little grey window with the greeting. To make a script directly executable (on Unix/Linux, and Cygwin on Windows), use this first line (the \# being flush left): ``` tcl #!/usr/bin/env tclsh ``` or (in an older, deprecated tricky style): ``` tcl #! /bin/sh # the next line restarts using tclsh \ exec tclsh "$0" ${1+"$@"} ``` This way, the shell can determine which executable to run the script with. An even simpler way, and highly recommended for beginners as well as experienced users, is to start up tclsh or wish interactively. You will see a % prompt in the console, can type commands to it, and watch its responses. Even error messages are very helpful here, and don\'t cause a program abort - don\'t be afraid to try whatever you like! Example: `$ tclsh` ``` tcl info patchlevel ``` `8.4.12` ``` tcl expr 67 ``` `42` ``` tcl expr 42/0 ``` `divide by zero` You can even write programs interactively, best as one-liners: ``` tcl proc ! x {expr {$x<=2? $x: $x[! [incr x -1]]}} ! 5 ``` `120` For more examples, see the chapter \"A quick tour\". ------------------------------------------------------------------------ ### Syntax Syntax is just the rules how a language is structured. A simple syntax of English could say (ignoring punctuation for the moment): - A text consists of one or more sentences - A sentence consists of one or more words Simple as this is, it also describes Tcl\'s syntax very well - if you say \"script\" for \"text\", and \"command\" for \"sentence\". There\'s also the difference that a Tcl word can again contain a script or a command. So ``` tcl if {$x < 0} {set x 0} ``` is a command consisting of three words: if, a condition in braces, a command (also consisting of three words) in braces. ``` tcl Take this for example ``` is a well-formed Tcl command: it calls Take (which must have been defined before) with the three arguments \"this\", \"for\", and \"example\". It is up to the command how it interprets its arguments, e.g. ``` tcl puts acos(-1) ``` will write the string \"acos(-1)\" to the stdout channel, and return the empty string \"\", while ``` tcl expr acos(-1) ``` will compute the arc cosine of -1 and return 3.14159265359 (an approximation of Pi), or ``` tcl string length acos(-1) ``` will invoke the string command, which again dispatches to its length sub-command, which determines the length of the second argument and returns 8. #### Quick summary A Tcl script is a string that is a sequence of commands, separated by newlines or semicolons. A command is a string that is a list of words, separated by blanks. The first word is the name of the command, the other words are passed to it as its arguments. In Tcl, \"everything is a command\" - even what in other languages would be called declaration, definition, or control structure. A command can interpret its arguments in any way it wants - in particular, it can implement a different language, like expr. A word is a string that is a simple word, or one that begins with { and ends with the matching } (braces), or one that begins with \" and ends with the matching \". Braced words are not evaluated by the parser. In quoted words, substitutions can occur before the command is called: - \$\[A-Za-z0-9\_\]+ substitutes the value of the given variable. Or, if the variable name contains characters outside that regular expression, another layer of bracing helps the parser to get it right: `puts "Guten Morgen, ${Schüler}!"` If the code would say \$Schüler, this would be parsed as the value of variable \$Sch, immediately followed by the constant string üler. - (Part of) a word can be an embedded script: a string in \[\] brackets whose contents are evaluated as a script (see above) before the current command is called. In short: Scripts and commands contain words. Words can again contain scripts and commands. (This can lead to words more than a page long\...) Arithmetic and logic expressions are not part of the Tcl language itself, but the language of the expr command (also used in some arguments of the if, for, while commands) is basically equivalent to C\'s expressions, with infix operators and functions. See separate chapter on expr below. ------------------------------------------------------------------------ #### The man page: 11 rules Here is the complete manpage for Tcl (8.4) with the \"endekalogue\", the 11 rules. (From 8.5 onward there is a twelfth rule regarding the {\} feature). The following rules define the syntax and semantics of the Tcl language: (1) Commands* A Tcl script is a string containing one or more commands. Semi-colons and newlines are command separators unless quoted as described below. Close brackets are command terminators during command substitution (see below) unless quoted. (2) Evaluation A command is evaluated in two steps. First, the Tcl interpreter breaks the command into words and performs substitutions as described below. These substitutions are performed in the same way for all commands. The first word is used to locate a command procedure to carry out the command, then all of the words of the command are passed to the command procedure. The command procedure is free to interpret each of its words in any way it likes, such as an integer, variable name, list, or Tcl script. Different commands interpret their words differently. (3) Words Words of a command are separated by white space (except for newlines, which are command separators). (4) Double quotes If the first character of a word is double-quote (\") then the word is terminated by the next double-quote character. If semi-colons, close brackets, or white space characters (including newlines) appear between the quotes then they are treated as ordinary characters and included in the word. Command substitution, variable substitution, and backslash substitution are performed on the characters between the quotes as described below. The double-quotes are not retained as part of the word. (5) Braces If the first character of a word is an open brace ({) then the word is terminated by the matching close brace (}). Braces nest within the word: for each additional open brace there must be an additional close brace (however, if an open brace or close brace within the word is quoted with a backslash then it is not counted in locating the matching close brace). No substitutions are performed on the characters between the braces except for backslash-newline substitutions described below, nor do semi-colons, newlines, close brackets, or white space receive any special interpretation. The word will consist of exactly the characters between the outer braces, not including the braces themselves. (6) Command substitution If a word contains an open bracket (\[) then Tcl performs command substitution. To do this it invokes the Tcl interpreter recursively to process the characters following the open bracket as a Tcl script. The script may contain any number of commands and must be terminated by a close bracket (\]). The result of the script (i.e. the result of its last command) is substituted into the word in place of the brackets and all of the characters between them. There may be any number of command substitutions in a single word. Command substitution is not performed on words enclosed in braces. (7) Variable substitution If a word contains a dollar-sign (\$) then Tcl performs variable substitution: the dollar-sign and the following characters are replaced in the word by the value of a variable. Variable substitution may take any of the following forms: \$name Name is the name of a scalar variable; the name is a sequence of one or more characters that are a letter, digit, underscore, or namespace separators (two or more colons). \$name(index) Name gives the name of an array variable and index gives the name of an element within that array. Name must contain only letters, digits, underscores, and namespace separators, and may be an empty string. Command substitutions, variable substitutions, and backslash substitutions are performed on the characters of index. \${name} Name is the name of a scalar variable. It may contain any characters whatsoever except for close braces. There may be any number of variable substitutions in a single word. Variable substitution is not performed on words enclosed in braces. (8) Backslash substitution If a backslash (\\) appears within a word then backslash substitution occurs. In all cases but those described below the backslash is dropped and the following character is treated as an ordinary character and included in the word. This allows characters such as double quotes, close brackets, and dollar signs to be included in words without triggering special processing. The following table lists the backslash sequences that are handled specially, along with the value that replaces each sequence. \\a : Audible alert (bell) (0x7). \\b : Backspace (0x8). \\f : Form feed (0xc). \\n : Newline (0xa). \\r : Carriage-return (0xd). \\t : Tab (0x9). \\v : Vertical tab (0xb). \\`<newline>`{=html}whiteSpace : A single space character replaces the backslash, newline, and all spaces and tabs after the newline. This backslash sequence is unique in that it is replaced in a separate pre-pass before the command is actually parsed. This means that it will be replaced even when it occurs between braces, and the resulting space will be treated as a word separator if it isn\'t in braces or quotes. \\\\ : Literal backslash (\\), no special effect. \\ooo : The digits ooo (one, two, or three of them) give an eight-bit octal value for the Unicode character that will be inserted. The upper bits of the Unicode character will be 0. \\xhh : The hexadecimal digits hh give an eight-bit hexadecimal value for the Unicode character that will be inserted. Any number of hexadecimal digits may be present; however, all but the last two are ignored (the result is always a one-byte quantity). The upper bits of the Unicode character will be 0. \\uhhhh : The hexadecimal digits hhhh (one, two, three, or four of them) give a sixteen-bit hexadecimal value for the Unicode character that will be inserted. Backslash substitution is not performed on words enclosed in braces, except for backslash-newline as described above. (9) Comments If a hash character (#) appears at a point where Tcl is expecting the first character of the first word of a command, then the hash character and the characters that follow it, up through the next newline, are treated as a comment and ignored. The comment character only has significance when it appears at the beginning of a command. (10) Order of substitution Each character is processed exactly once by the Tcl interpreter as part of creating the words of a command. For example, if variable substitution occurs then no further substitutions are performed on the value of the variable; the value is inserted into the word verbatim. If command substitution occurs then the nested command is processed entirely by the recursive call to the Tcl interpreter; no substitutions are performed before making the recursive call and no additional substitutions are performed on the result of the nested script. Substitutions take place from left to right, and each substitution is evaluated completely before attempting to evaluate the next. Thus, a sequence like ``` tcl set y [set x 0][incr x][incr x] ``` will always set the variable y to the value, 012. (11) Substitution and word boundaries Substitutions do not affect the word boundaries of a command. For example, during variable substitution the entire value of the variable becomes part of a single word, even if the variable\'s value contains spaces. #### Comments The first rule for comments is simple: comments start with \# where the first word of a command is expected, and continue to the end of line (which can be extended, by a trailing backslash, to the following line): ``` tcl # This is a comment \ going over three lines \ with backslash continuation ``` One of the problems new users of Tcl meet sooner or later is that comments behave in an unexpected way. For example, if you comment out part of code like this: ``` tcl # if {$condition} { puts "condition met!" # } ``` This happens to work, but any unbalanced braces in comments may lead to unexpected syntax errors. The reason is that Tcl\'s grouping (determining word boundaries) happens before the \# characters are considered. To add a comment behind a command on the same line, just add a semicolon: ``` tcl puts "this is the command" ;# that is the comment ``` Comments are only taken as such where a command is expected. In data (like the comparison values in switch), a \# is just a literal character: ``` tcl if $condition {# good place switch -- $x { #bad_place {because switch tests against it} some_value {do something; # good place again} } } ``` To comment out multiple lines of code, it is easiest to use \"if 0\": ``` tcl if 0 { puts "This code will not be executed" This block is never parsed, so can contain almost any code - except unbalanced braces :) } ``` ### Data types In Tcl, all values are strings, and the phrase \"Everything is a string\" is often used to illustrate this fact. But just as `2` can be interpreted in English as \"the number 2\" or \"the character representing the number 2\", two different functions in Tcl can interpret the same value in two different ways. The command `expr`, for example, interprets \"2\" as a number, but the command `string length` interprets \"2\" as a single character. All values in Tcl can be interpreted either as characters or something else that the characters represent. The important thing to remember is that every value in Tcl is a string of characters, and each string of characters might be interpreted as something else, depending on the context. This will become more clear in the examples below. For performance reasons, versions of Tcl since 8.0 keep track of both the string value and how that string value was last interpreted. This section covers the various \"types\" of things that Tcl values (strings) get interpreted as. #### Strings A string is a sequence of zero or more characters (where all 16-bit Unicodes are accepted in almost all situations, see in more detail below). The size of strings is automatically administered, so you only have to worry about that if the string length exceeds the virtual memory size. In contrast to many other languages, strings in Tcl don\'t need quotes for markup. The following is perfectly valid: ``` tcl set greeting Hello! ``` Quotes (or braces) are rather used for grouping: ``` tcl set example "this is one word" set another {this is another} ``` The difference is that inside quotes, substitutions (like of variables, embedded commands, or backslashes) are performed, while in braces, they are not (similar to single quotes in shells, but nestable): ``` tcl set amount 42 puts "You owe me $amount" ;#--> You owe me 42 puts {You owe me $amount} ;#--> You owe me $amount ``` In source code, quoted or braced strings can span multiple lines, and the physical newlines are part of the string too: ``` tcl set test "hello world in three lines" ``` To reverse a string, we let an index i first point at its end, and decrementing i until it\'s zero, append the indexed character to the end of the result res: ``` tcl proc sreverse str { set res "" for {set i [string length $str]} {$i > 0} {} { append res [string index $str [incr i -1]] } set res } sreverse "A man, a plan, a canal - Panama" ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text amanaP - lanac a ,nalp a ,nam A ``` ```{=html} </dd> ``` ```{=html} </dl> ``` Hex-dumping a string: ``` tcl proc hexdump string { binary scan $string H* hex regexp -all -inline .. $hex } hexdump hello ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text 68 65 6c 6c 6f ``` ```{=html} </dd> ``` ```{=html} </dl> ``` Finding a substring in a string can be done in various ways: ``` tcl string first $substr $str ;# returns the position from 0, or -1 if not found ``` ``` tcl string match $substr $str ;# returns 1 if found, 0 if not ``` ``` tcl regexp $substr $str ;# the same ``` The matching is done with exact match in string first, with glob-style match in string match, and as a regular expression in regexp. If there are characters in substr that are special to glob or regular expressions, using string first is recommended. #### Lists Many strings are also well-formed lists. Every simple word is a list of length one, and elements of longer lists are separated by whitespace. For instance, a string that corresponds to a list of three elements: ``` tcl set example {foo bar grill} ``` Strings with unbalanced quotes or braces, or non-space characters directly following closing braces, cannot be parsed as lists directly. You can explicitly split them to make a list. The \"constructor\" for lists is of course called list. It\'s recommended to use when elements come from variable or command substitution (braces won\'t do that). As Tcl commands are lists anyway, the following is a full substitute for the list command: ``` tcl proc list args {set args} ``` Lists can contain lists again, to any depth, which makes modelling of matrixes and trees easy. Here\'s a string that represents a 4 x 4 unit matrix as a list of lists. The outer braces group the entire thing into one string, which includes the literal inner braces and whitespace, including the literal newlines. The list parser then interprets the inner braces as delimiting nested lists. ``` tcl {{1 0 0 0} {0 1 0 0} {0 0 1 0} {0 0 0 1}} ``` The newlines are valid list element separators, too. Tcl\'s list operations are demonstrated in some examples: ``` tcl set x {foo bar} llength $x ;#--> 2 lappend x grill ;#--> foo bar grill lindex $x 1 ;#--> bar (indexing starts at 0) lsearch $x grill ;#--> 2 (the position, counting from 0) lsort $x ;#--> bar foo grill linsert $x 2 and ;#--> foo bar and grill lreplace $x 1 1 bar, ;#--> foo bar, grill ``` Note that only lappend, above is mutating. To change an element of a list (of a list\...) in place, the lset command is useful - just give as many indexes as needed: ``` tcl set test {{a b} {c d}} ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text {a b} {c d} ``` ```{=html} </dd> ``` ```{=html} </dl> ``` ``` tcl lset test 1 1 x ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text {a b} {c x} ``` ```{=html} </dd> ``` ```{=html} </dl> ``` The lindex command also takes multiple indexes: ``` tcl lindex $test 1 1 ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text x ``` ```{=html} </dd> ``` ```{=html} </dl> ``` Example: To find out whether an element is contained in a list (from Tcl 8.5, there\'s the in operator for that): ``` tcl proc in {list el} {expr {[lsearch -exact $list $el] >= 0}} in {a b c} b ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text 1 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` ``` tcl in {a b c} d ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text #ignore this line, which is only here because there is currently a bug in wikibooks rendering which makes the 0 on the following line disappear when it is alone 0 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` Example: remove an element from a list variable by value (converse to lappend), if present: ``` tcl proc lremove {_list el} { upvar 1 $_list list set pos [lsearch -exact $list $el] set list [lreplace $list $pos $pos] } set t {foo bar grill} ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text foo bar grill ``` ```{=html} </dd> ``` ```{=html} </dl> ``` ``` tcl lremove t bar ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text foo grill ``` ```{=html} </dd> ``` ```{=html} </dl> ``` ``` tcl set t ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text foo grill ``` ```{=html} </dd> ``` ```{=html} </dl> ``` A simpler alternative, which also removes all occurrences of el: ``` tcl proc lremove {_list el} { upvar 1 $_list list set list [lsearch -all -inline -not -exact $list $el] } ``` Example: To draw a random element from a list L, we first determine its length (using llength), multiply that with a random number \> 0.0 and \< 1.0, truncate that to integer (so it lies between 0 and length-1), and use that for indexing (lindex) into the list: ``` tcl proc ldraw L { lindex $L [expr {int(rand()[llength $L])}] } ``` Example: Transposing a matrix (swapping rows and columns), using integers as generated variable names: ``` tcl proc transpose matrix { foreach row $matrix { set i 0 foreach el $row {lappend [incr i] $el} } set res {} set i 0 foreach e [lindex $matrix 0] {lappend res [set [incr i]]} set res } transpose {{1 2} {3 4} {5 6}} ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text {1 3 5} {2 4 6} ``` ```{=html} </dd> ``` ```{=html} </dl> ``` Example: pretty-printing a list of lists which represents a table: ``` tcl proc fmtable table { set maxs {} foreach item [lindex $table 0] { lappend maxs [string length $item] } foreach row [lrange $table 1 end] { set i 0 foreach item $row max $maxs { if {[string length $item]>$max} { lset maxs $i [string length $item] } incr i } } set head + foreach max $maxs {append head -[string repeat - $max]-+} set res $head\n foreach row $table { append res \| foreach item $row max $maxs {append res [format " %-${max}s \|" $item]} append res \n } append res $head } ``` Testing: ``` tcl fmtable { {1 short "long field content"} {2 "another long one" short} {3 "" hello} } ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text +---+------------------+--------------------+ \| 1 \| short \| long field content \| \| 2 \| another long one \| short \| \| 3 \| \| hello \| +---+------------------+--------------------+ ``` ```{=html} </dd> ``` ```{=html} </dl> ``` Enumerations:* Lists can also be used to implement enumerations (mappings from symbols to non-negative integers). Example for a nice wrapper around lsearch/lindex: ``` tcl proc makeEnum {name values} { interp alias {} $name: {} lsearch $values interp alias {} $name@ {} lindex $values } makeEnum fruit {apple blueberry cherry date elderberry} ``` This assigns \"apple\" to 0, \"blueberry\" to 1, etc. ``` tcl fruit: date ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text 3 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` ``` tcl fruit@ 2 ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text cherry ``` ```{=html} </dd> ``` ```{=html} </dl> ``` #### Numbers Numbers are strings that can be parsed as such. Tcl supports integers (32-bit or even 64-bit wide) and \"double\" floating-point numbers. From Tcl 8.5 on, bignums (integers of arbitrarily large precision) are supported. Arithmetics is done with the expr command, which takes basically the same syntax of operators (including ternary x?y:z), parens, and math functions as C. See below for detailed discussion of expr. Control the display format of numbers with the format command which does appropriate rounding: ``` tcl expr 2/3. ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text 0.666666666667 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` ``` tcl format %.2f [expr 2/3.] ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text 0.67 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` Up to the 8.4 version (the present version is 8.5), Tcl honored the C convention that an integer starting with 0 is parsed as octal, so `0377 == 0xFF == 255` This changes in 8.5, though - too often people stumbled over \"08\" meant as hour or month, raised a syntax error, because 8 is no valid octal number. In the future you\'d have to write 0o377 if you really mean octal. You can do number base conversions with the format command, where the format is %x for hex, %d for decimal, %o for octal, and the input number should have the C-like markup to indicate its base: ``` tcl format %x 255 ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` tcl ff ``` ```{=html} </dd> ``` ```{=html} </dl> ``` ``` tcl format %d 0xff ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` tcl 255 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` ``` tcl format %o 255 ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text 377 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` ``` tcl format %d 0377 ``` ```{=html} <dl> ``` ```{=html} <dd> ``` : ``` text 255 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` Variables with integer value can be most efficiently modified with the incr command: ``` tcl incr i ;# default increment is 1 incr j 2 incr i -1 ;# decrement with negative value incr j $j ;# double the value ``` The maximal positive integer can be determined from the hexadecimal form, with a 7 in front, followed by several \"F\" characters. Tcl 8.4 can use \"wide integers\" of 64 bits, and the maximum integer there is ``` tcl expr 0x7fffffffffffffff ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text 9223372036854775807 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` Demonstration: one more, and it turns into the minimum integer: ``` tcl expr 0x8000000000000000 ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text -9223372036854775808 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` Bignums: from Tcl 8.5, integers can be of arbitrary size, so there is no maximum integer anymore. Say, you want a big factorial: ``` tcl proc tcl::mathfunc::fac x {expr {$x < 2? 1: $x * fac($x-1)}} expr fac(100) ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text 93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` IEEE special floating-point values: Also from 8.5, Tcl supports a few special values for floating-point numbers, namely Inf (infinity) and NaN (Not a Number): ``` tcl set i [expr 1/0.] ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text Inf ``` ```{=html} </dd> ``` ```{=html} </dl> ``` ``` tcl expr {$i+$i} ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text Inf ``` ```{=html} </dd> ``` ```{=html} </dl> ``` ``` tcl expr {$i+1 == $i} ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text 1 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` ``` tcl set j NaN ;# special because it isn't equal to itself ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text NaN ``` ```{=html} </dd> ``` ```{=html} </dl> ``` ``` tcl expr {$j == $j} ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text #ignore this line, which is only here because there is currently a bug in wikibooks rendering which makes the 0 on the following line disappear when it is alone 0 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` #### Booleans Tcl supports booleans as numbers in a similar fashion to C, with 0 being false and any other number being true. It also supports them as the strings \"true\", \"false\", \"yes\" and \"no\" and few others (see below). The canonical \"true\" value (as returned by Boolean expressions) is 1. ``` tcl foreach b {0 1 2 13 true false on off no yes n y a} {puts "$b -> [expr {$b?1:0}]"} ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text 0 -> 0 1 -> 1 2 -> 1 13 -> 1 true -> 1 false -> 0 on -> 1 off -> 0 no -> 0 yes -> 1 n -> 0 y -> 1 expected boolean value but got "a" ``` ```{=html} </dd> ``` ```{=html} </dl> ``` #### Characters Characters are abstractions of writing elements (e.g. letters, digits, punctuation characters, Chinese ideographs, ligatures\...). In Tcl since 8.1, characters are internally represented with Unicode, which can be seen as unsigned integers between 0 and 65535 (recent Unicode versions have even crossed that boundary, but the Tcl implementation currently uses a maximum of 16 bits). Any Unicode U+XXXX can be specified as a character constant with an \\uXXXX escape. It is recommended to only use ASCII characters (\\u0000-\\u007f) in Tcl scripts directly, and escape all others. Convert between numeric Unicode and characters with ``` tcl set char [format %c $int] set int [scan $char %c] ``` Watch out that int values above 65535 produce \'decreasing\' characters again, while negative int even produces two bogus characters. format does not warn, so better test before calling it. Sequences of characters are called strings (see above). There is no special data type for a single character, so a single character is just a string on length 1 (everything is a string). In UTF-8, which is used internally by Tcl, the encoding of a single character may take from one to three bytes of space. To determine the bytelength of a single character: ``` tcl string bytelength $c ;# assuming [string length $c]==1 ``` String routines can be applied to single characters too, e.g \[string toupper\] etc. Find out whether a character is in a given set (a character string) with ``` tcl expr {[string first $char $set]>=0} ``` As Unicodes for characters fall in distinct ranges, checking whether a character\'s code lies within a range allows a more-or-less rough classification of its category: ``` tcl proc inRange {from to char} { # generic range checker set int [scan $char %c] expr {$int>=$from && $int <= $to} } interp alias {} isGreek {} inRange 0x0386 0x03D6 interp alias {} isCyrillic {} inRange 0x0400 0x04F9 interp alias {} isHangul {} inRange 0xAC00 0xD7A3 ``` This is a useful helper to convert all characters beyond the ASCII set to their \\u\.... escapes (so the resulting string is strict ASCII): ``` tcl proc u2x s { set res "" foreach c [split $s ""] { scan $c %c int append res [expr {$int<128? $c :"\\u[format %04.4X $int]"}] } set res } ``` #### Internal representation In the main Tcl implementation, which is written in C, each value has both a string representation (UTF-8 encoded) and a structured representation. This is an implementation detail which allows for better performance, but has no semantic impact on the language. Tcl tracks both representations, making sure that if one is changed, the other one is updated to reflect the change the next time it is used. For example, if the string representation of a value is \"8\", and the value was last used as a number in an \[expr\] command, the structured representation will be a numeric type like a signed integer or a double-precision floating point number. If the value \"one two three\" was last used in one of the list commands, the structured representation will be a list structure. There are various other \"types\" on the C side which may be used as the structured representation. As of Tcl 8.5, only the most recent structured representation of a value is stored, and it is replaced with a different representation when necessary. This \"dual-porting\" of values helps avoid, repeated parsing or \"stringification\", which otherwise would happen often because each time a value is encountered in source code, it is interpreted as a string prior to being interpreted in its current context. But to the programmer, the view that \"everything is a string\" is still maintained. These values are stored in reference-counted structures termed objects (a term that has many meanings). From the perspective of all code that uses values (as opposed to code implementing a particular representation), they are immutable. In practice, this is implemented using a copy-on-write strategy. ### Variables Variables can be local or global, and scalar or array. Their names can be any string not containing a colon (which is reserved for use in namespace separators) but for the convenience of \$-dereference one usually uses names of the pattern \[A-Za-z0-9\_\]+, i.e. one or more letters, digits, or underscores. Variables need not be declared beforehand. They are created when first assigned a value, if they did not exist before, and can be unset when no longer needed: ``` tcl set foo 42 ;# creates the scalar variable foo set bar(1) grill ;# creates the array bar and its element 1 set baz $foo ;# assigns to baz the value of foo set baz [set foo] ;# the same effect info exists foo ;# returns 1 if the variable foo exists, else 0 unset foo ;# deletes the variable foo ``` Retrieving a variable\'s value with the \$foo notation is only syntactic sugar for \[set foo\]. The latter is more powerful though, as it can be nested, for deeper dereferencing: ``` tcl set foo 42 set bar foo set grill bar puts [set [set [set grill]]] ;# gives 42 ``` Some people might expect \$\$\$grill to deliver the same result, but it doesn\'t, because of the Tcl parser. When it encounters the first and second \$ sign, it tries to find a variable name (consisting of one or more letters, digits, or underscores) in vain, so these \$ signs are left literally as they are. The third \$ allows substitution of the variable grill, but no backtracking to the previous \$\'s takes place. So the evaluation result of \$\$\$grill is \$\$bar. Nested \[set\] commands give the user more control. #### Local vs. global A local variable exists only in the procedure where it is defined, and is freed as soon as the procedure finishes. By default, all variables used in a proc are local. Global variables exist outside of procedures, as long as they are not explicitly unset. They may be needed for long-living data, or implicit communication between different procedures, but in general it\'s safer and more efficient to use globals as sparingly as possible. Example of a very simple bank with only one account: ``` tcl set balance 0 ;# this creates and initializes a global variable proc deposit {amount} { global balance set balance [expr {$balance + $amount}] } proc withdraw {amount} { set ::balance [expr {$::balance - $amount}] } ``` This illustrates two ways of referring to global variables - either with the global command, or by qualifying the variable name with the :: prefix. The variable amount is local in both procedures, and its value is that of the first argument to the respective procedure. Introspection: ``` tcl info vars ;#-- lists all visible variables info locals info globals ``` To make all global variables visible in a procedure (not recommended): ``` tcl eval global [info globals] ``` #### Scalar vs. array All of the value types discussed above in Data types can be put into a scalar variable, which is the normal kind. Arrays are collections of variables, indexed by a key that can be any string, and in fact implemented as hash tables. What other languages call \"arrays\" (vectors of values indexed by an integer), would in Tcl rather be lists. Some illustrations: ``` tcl #-- The key is specified in parens after the array name set capital(France) Paris #-- The key can also be substituted from a variable: set country France puts $capital($country) #-- Setting several elements at once: array set capital {Italy Rome Germany Berlin} #-- Retrieve all keys: array names capital ;#-- Germany Italy France -- quasi-random order #-- Retrieve keys matching a glob pattern: array names capital F* ;#-- France ``` A fanciful array name is \"\" (the empty string, therefore we might call this the \"anonymous array\" :) which makes nice reading: ``` tcl set (example) 1 puts $(example) ``` Note that arrays themselves are not values. They can be passed in and out of procedures not as \$capital (which would try to retrieve the value), but by reference. The dict type (available from Tcl 8.5) might be better suited for these purposes, while otherwise providing hash table functionality, too. #### System variables At startup, tclsh provides the following global variables: argc : number of arguments on the command line\ argv : list of the arguments on the command line\ argv0 : name of the executable or script (first word on command line)\ auto_index : array with instructions from where to load further commands\ auto_oldpath : (same as auto_path ?)\ auto_path : list of paths to search for packages\ env : array, mirrors the environment variables\ errorCode : type of the last error, or {}, e.g. ARITH DIVZERO {divide by zero}\ errorInfo : last error message, or {}\ tcl_interactive : 1 if interpreter is interactive, else 0\ tcl_libPath : list of library paths\ tcl_library : path of the Tcl system library directory\ tcl_patchLevel : detailed version number, e.g. 8.4.11\ tcl_platform : array with information on the operating system\ tcl_rcFileName : name of the initial resource file\ tcl_version : brief version number, e.g. 8.4 One can use temporary environment variables to control a Tcl script from the command line, at least in Unixoid systems including Cygwin. Example scriptlet: ``` tcl set foo 42 if [info exists env(DO)] {eval $env(DO)} puts foo=$foo ``` This script will typically report ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text foo=42 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` To remote-control it without editing, set the DO variable before the call: ``` bash DO='set foo 4711' tclsh myscript.tcl ``` which will evidently report ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text foo=4711 ``` ```{=html} </dd> ``` ```{=html} </dl> ``` #### Dereferencing variables A reference is something that refers, or points, to another something (if you pardon the scientific expression). In C, references are done with \pointers\ (memory addresses); in Tcl, references are strings (everything is a string), namely names of variables, which via a hash table can be resolved (dereferenced) to the \"other something\" they point to: ``` tcl puts foo ;# just the string foo puts $foo ;# dereference variable with name of foo puts [set foo] ;# the same ``` This can be done more than one time with nested set commands. Compare the following C and Tcl programs, that do the same (trivial) job, and exhibit remarkable similarity: ``` c #include <stdio.h> int main(void) { int i = 42; int * ip = &i; int ipp = &ip; int ippp = &ipp; printf("hello, %d\n", **ippp); return 0; } ``` \...and Tcl: ``` tcl set i 42 set ip i set ipp ip set ippp ipp puts "hello, [set [set [set [set ippp]]]]" ``` The asterisks in C correspond to calls to `set` in Tcl dereferencing. There is no corresponding operator to the C `&` because, in Tcl, special markup is not needed in declaring references. The correspondence is not perfect; there are four `set` calls and only three asterisks. This is because mentioning a variable in C is an implicit dereference. In this case, the dereference is used to pass its value into printf. Tcl makes all four dereferences explicit (thus, if you only had 3 set calls, you\'d see hello, i). A single dereference is used so frequently that it is typically abbreviated with \$varname, e.g. ``` tcl puts "hello, [set [set [set $ippp]]]" ``` has set where C uses asterisks, and \$ for the last (default) dereference. The hashtable for variable names is either global, for code evaluated in that scope, or local to a proc. You can still \"import\" references to variables in scopes that are \"higher\" in the call stack, with the upvar and global commands. (The latter being automatic in C if the names are unique. If there are identical names in C, the innermost scope wins). #### Variable traces One special feature of Tcl is that you can associate traces with variables (scalars, arrays, or array elements) that are evaluated optionally when the variable is read, written to, or unset. Debugging is one obvious use for that. But there are more possibilities. For instance, you can introduce constants where any attempt to change their value raises an error: ``` tcl proc const {name value} { uplevel 1 [list set $name $value] uplevel 1 [list trace var $name w {error constant ;#} ] } const x 11 incr x ``` ```{=html} <dl> ``` ```{=html} <dd> ``` ``` text can't set "x": constant ``` ```{=html} </dd> ``` ```{=html} </dl> ``` The trace callback gets three words appended: the name of the variable; the array key (if the variable is an array, else \"\"), and the mode: - r - read - w - write - u - unset If the trace is just a single command like above, and you don\'t want to handle these three, use a comment \";#\" to shield them off. Another possibility is tying local objects (or procs) with a variable - if the variable is unset, the object/proc is destroyed/renamed away.
# Tcl Programming/Functions ### Commands ------------------------------------------------------------------------ Commands are basically divided into C-defined ones, procedures, and aliases (and, from Tcl 8.5 onwards, ensembles). You can rename any command with `rename oldname newname` To delete a command (make it no more reachable), use the empty string as new name: `rename oldname {}` Introspection: Get a list of all defined commands with `info commands` #### C-defined commands These are implemented in C and registered to be available in the Tcl interpreter. They can come from the Tcl core, or a loaded shared library (DLL) - for instance Tk. To get a list of built-in commands, subtract the result of info procs from that of info commands: `set builtins {}`\ `set procs [info procs]`\ `foreach cmd [info commands] {`\ ` if {[lsearch -exact $procs $cmd] == -1} {lappend builtins $cmd}`\ `}` The following C-defined commands are available in a fresh tclsh. For detailed documentation, see the respective man pages, e.g. at <http://www.tcl.tk/man/tcl8.5/TclCmd/> - I will characterize each only very briefly: after : group of commands for timed events\ after msec ?script? : waits, or executes the script after, some time\ append varName arg..: appends the arguments to a string variable\ array : group of commands for arrays\ binary : group of commands for binary scanning and formatting\ break : terminate current loop\ case : deprecated, use switch\ catch script ?varName? : catch possible error in script\ cd path : change working directory\ clock : group of commands dealing with date and time\ close handle : closes a channel (file, socket, etc.)\ concat list.. : make one space-separated list of the arguments\ continue : start next turn of current loop\ encoding : group of commands dealing with character set encoding\ eof handle : 1 if channel is at end of file, else 0\ error message ?info? ?code? : raise an error with the given message\ eval arg.. : evaluate the arguments as script\ exec file arg.. : execute a separate process\ exit ?int? : terminate this process, return status 0..127\ expr arg.. : arithmetic and logic engine, using C-like syntax and functions (variables referenced with \$name). In addition, from Tcl 8.4 there are eq and ne operators for string equal or not; from 8.5, also in and ni operators for list inclusion or not `expr {"foo" in {foo bar grill}} == 1` The argument to expr should in most cases be {braced}. This prevents the Tcl parser from substituting variables in advance, while expr itself has to parse the value from the string. In a braced expression expr can parse variable references itself, and get their numeric value directly where possible. Much faster, usually. The only exception, where bracing should not be used, is if you want to substitute operators from variables: `foreach op {+ - * /} {puts [expr 1 $op 2]}` fblocked handle : returns 1 if the last input operation exhausted all available input, else 0\ fconfigure handle -option value\... : configure a channel, e.g. its encoding or line-end translation\ fcopy handle1 handle2 : copy data from handle1 to handle2\ file : group of commands dealing with files\ fileevent : group of commands dealing with events from channels (readable, writable) but not files\ flush handle : make sure the channel\'s buffer is written out. Useful after puts -nonewline\ for initbody condition stepbody body : loop, somehow similar to C\'s for\ foreach varlist list ?varlist list\...? body : loop over one or more lists, The varlists can be a single or multiple varNames. Example: `% foreach {x y} {1 0 1 2 0 2 0 0} {puts "x:$x, y:$y"}`\ `x:1, y:0`\ `x:1, y:2`\ `x:0, y:2`\ `x:0, y:0` format fstring arg.. : put the arguments %-formatted into fstring, similar to C\'s sprintf()\ gets handle ?varName? : read a line from handle. If variable is given, assigns the line to it and returns the number of characters read; else returns the line. Guaranteed to be safe against buffer overflows\ glob ?-options? pattern.. : list of files matching the glob pattern (which can contain \* and ? wildcards)\ global varName.. : declare the given variable(s) as global\ history : list the last interactive commands\ if condition ?then? body1 ?elseif condition body2\...? ??else? bodyN? : conditional\ incr varName ?amount? : increments the integer variable by given amount (defaults to 1). Use negative amount to decrement\ info : group of commands for introspection\ interp : group of commands for interpreters\ join list ?separator? : Turn a list into a string, with separator between elements (defaults to \" \")\ lappend varName arg.. : appends the arguments to the list variable. Can also be used to make sure a variable exists: `lappend x ;# corresponds to: if {![info exists x]} {set x ""}` lindex list int.. : retrieve an element from the list by integer index(es)\ linsert list int arg.. : inserts the arguments at int position into list\ list ?arg..? : creates a list from the arguments\ llength list : length of the list\ load filename ?name? : loads a shared library (DLL)\ lrange list from to : returns a sublist at integer indexes from-to\ lreplace list from to arg.. : replaces the sublist in list with the arguments\ lsearch ?-options? list element : searches the list for the element, returns its integer index, or -1 if not found. Can be used to select a subset of elements from a list (using the -all option)\ lset varName int.. value : sets an existing element in the named list variable, indexed by integer(s), to the given value\ lsort ?-options? list : sorts the list\ namespace : group of commands dealing with namespaces\ open name ?mode ?permissions?? : opens a file or pipe, returns the handle\ package : group of commands dealing with packages\ pid ?handle?: returns the id of the current process. Can also return the list of pids for a pipeline given the pipeline channel ```{=html} <!-- --> ``` proc name arglist body : defines a procedure\ puts ?-nonewline? ?channel? string : outputs a line to the given channel (default stdout) To prevent errors from closed pipe (like more or head), use `proc puts! str {if [catch {puts $str}] exit}` pwd : returns the current working directory\ read handle ?int? : reads int bytes from handle (all if int not given)\ regexp ?-options? re string ?varName\...? : regular expression matching of re in string, possibly assigning parenthesized submatches to the given variables\ regsub ?-options? re value substring ?varName?: substitutes occurrences of the regular expression re in value with substring. If varName is given, assigns the new value to it, and returns the number of substitutions; else returns the new value\ rename cmdName1 cmdName2: renames a command from cmdName1 to cmdName2, or deletes cmdName1 if cmdName2 is {}\ return ?value? : exits from the current proc or sourced script\ scan string format ?varName\...? : extracts values by %-format in string to the given variables. Similar to C\'s sscanf()\ seek channelId offset ?origin? : moves pointer in file to the given position\ set varName ?value? : sets variable to value if given, and returns the variable\'s value\ socket ?-myaddr addr? ?-myport myport? ?-async? host port : open the client side of a TCP connection as a channel\ socket -server command ?-myaddr addr? port : open the server side of a TCP connection, register a handler callbacvk command for client requests\ source filename : evaluate the contents of the given file\ split list ?charset? : splits a string into a list, using any of the characters in charset string as delimiters (defaults to \" \")\ string : group of commands dealing with strings\ subst ?-options? string : performs command, variable, and/or backslash substitutions in string\ switch ?-options? ?\--? value alternatives : performs one of the alternatives if the value matches\ tell handle : return the byte position inside a file\ time body ?int? : runs the body for int times (default 1), returns how many microseconds per iteration were used\ trace : group of commands to tie actions to variables or commands\ unset varName.. : delete the given variable(s)\ update ?idletasks? : services events\ uplevel ?level? body : evaluates the body up in the call stack\ upvar ?level? varName localVarName\... : ties the given variables up in the call stack to the given local variables. Used for calling by reference, e.g. for arrays\ variable varName ?value ?varName value\...?? : declare the variables as being non-local in a namespace\ vwait varName : suspend execution until the given variable has changed. Starts event loop, if not active yet\ while condition body: performs body as long as condition is not 0 #### Procedures Procedures in Tcl cover what other languages call procedures, subroutines, or functions. They always return a result (even if it is the empty string \"\"), so to call them functions might be most appropriate. But for historical reasons, the Tcl command to create a function is called proc and thus people most often call them procedures. `proc name argumentlist body` Examples: `proc sum {a b} {return [expr {$a+$b}]}` The return is redundant, as the proc returns anyway when reaching its end, and returning its last result: `proc sum {a b} {expr {$a+$b}}` The following variant is more flexible, as it takes any number of arguments (the special argument name args collects all remaining arguments into a list, which is the value of the parameter args): `proc sum args {`\ ` set res 0`\ ` foreach arg $args {set res [expr {$res + $arg}]}`\ ` return $res`\ `}` An elegant but less efficient alternative builds a string by joining the args with plus signs, and feeds that to expr: `proc sum args {expr [join $args +]}` If an argument in a proc definition is a list of two elements, the second is taken as default value if not given in the call (\"Sir\" in this example): `proc greet {time {person Sir}} {return "good $time, $person"}` `% greet morning John`\ `good morning, John`\ `% greet evening`\ `good evening, Sir` Introspection: Get the names of all defined procedures with `info procs` There are also info subcommands to get the argument list, and possible default arguments, and body of a proc. The following example combines them to recreate the textual form of a proc, given its name (corp being proc in reverse): `proc corp name {`\ ` set argl {}`\ ` foreach arg [info args $name] {`\ ` if [info default $name $arg def] {lappend arg $def}`\ ` lappend argl $arg`\ ` }`\ ` list proc $name $argl [info body $name]`\ `}` Using rename, you can overload any command, including the C-coded ones. First rename the original command to something else, then reimplement it with the same signature, where ultimately the original is called. Here is for instance an overloaded proc that reports if a procedure is defined more than once with same name: `rename proc _proc`\ `_proc proc {name argl body} {`\ ` if {[info procs $name] eq $name} {`\ ` puts "proc $name redefined in [info script]"`\ ` }`\ ` _proc $name $argl $body`\ `}` Named arguments: Arguments to commands are mostly by position. But it\'s very easy to add the behavior known from Python or Ada, that arguments can be named in function calls, which documents the code a bit better, and allows any order of arguments. The idea (as found in Welch\'s book) is to use an array (here called \"\" - the \"anonymous array\") keyed by argument names. Initially, you can set some default values, and possibly override them with the args of the proc (which has to be paired, i.e. contain an even number of elements): `proc named {args defaults} {`\ ` upvar 1 "" ""`\ ` array set "" $defaults`\ ` foreach {key value} $args {`\ ` if {![info exists ($key)]} {`\ ` set names [lsort [array names ""]]`\ ` error "bad option '$key', should be one of: $names"`\ ` }`\ ` set ($key) $value`\ ` }`\ `}` Usage example: `proc replace {s args} {`\ ` named $args {-from 0 -to end -with ""}`\ ` string replace $s $(-from) $(-to) $(-with)`\ `}` Testing: `% replace suchenwirth -from 4 -to 6 -with xx`\ `suchxxirth`\ `% replace suchenwirth -from 4 -to 6 -witha xx`\ `bad option '-witha', should be one of: -from -to -with` #### Argument passing by name or value Normally, arguments to commands are passed by value (as constants, or with \$ prefixed to a variable name). This securely prevents side-effects, as the command will only get a copy of the value, and not be able to change the variable. However, sometimes just that is wanted. Imagine you want a custom command to set a variable to zero. In this case, at call time specify the name of the variable (without \$), and in the proc use upvar to link the name (in the scope \"1 up\", i.e. the caller\'s) to a local variable. I usually put a \"\_\" before arguments that are variable names (e.g. \_var), and upvar to the same name without \"\_\" (e.g. var): `% proc zero _var {upvar 1 $_var var; set var 0}` `% set try 42`\ `42`\ `% zero try`\ `0`\ `% set try`\ `0` If you often use call by reference, you could indicate such arguments with a special pattern (e.g. &arg) and have the following code generate the necessary upvars: `proc use_refs { {char &}} {`\ ` foreach v [uplevel 1 {info locals}] {`\ ` if [string match $char* $v] {`\ ` uplevel 1 "upvar 1 \${$v} [string range $v 1 end]"`\ ` }`\ ` }`\ `}` That\'s all. This command is preferably called first inside a proc, and upvars all arguments that begin with a specific character, the default being \"&\" - it runs code like `upvar 1 ${&foo} foo` in the caller\'s scope. Testing: `proc test_refs {a &b} {`\ ` use_refs`\ ` puts a=$a,b=$b`\ ` set b new_value`\ `}`\ `% set bar 42`\ `42`\ `% test_refs foo bar`\ `a=foo,b=42` So the values of a (by value) and b (by reference) are readable; and the side effect of changing b in the caller did also happen: `% set bar`\ `new_value` #### Variable scope Inside procedures, variables are by default local. They exist only in the proc, and are cleared up on return. However, you can tie local variables to others higher in the call stack (e.g. in the caller), up to the topmost global scope. Examples: `proc demo arg {`\ ` global g`\ ` set g 0 ;# will effect a lasting change in g`\ ` set local 1 ;# will disappear soon`\ ` set ::anotherGlobal 2 ;# another way to address a global variable`\ ` upvar 1 $arg myArg ;# make myArg point at a variable 1-up`\ ` set myArg 3 ;# changes that variable in the calling scope`\ `}` #### Aliases One can also define a command as an alias to a sequence of one or more words, which will be substituted for it before execution. (The funny {} arguments are names of the source and target interpreter, which typically is the current one, named by the empty string {} or \"\"). Examples: `interp alias {} strlen {} string length`\ `interp alias {} cp {} file copy -force` Introspection: Get the names of all defined aliases with `interp aliases` ------------------------------------------------------------------------ ### Advanced concepts ------------------------------------------------------------------------ #### Interpreters Tcl being an interpreted (plus on-the-fly byte-compiled) language, an interpreter is of course a central kind of object. Every time Tcl is running, at least one interpreter is running, who takes scripts and evaluates them. One can also create further \"slave\" interpreters to encapsulate data and processes, which again can have their \"sub-slaves\", etc., ultimately forming a tree hierarchy. Examples: `% interp create helper`\ `helper`\ `% helper eval {expr 76}`\ `42`\ `% interp delete helper`\ `% helper eval {expr 1+2}`\ `invalid command name "helper"` By deleting an interpreter, all its global (and namespaced) variables are freed too, so you can use this for modularisation and encapsulation, if needed. In particular, safe interpreters* have intentionally limited capabilities (for instance, access to the file system or the Web) so that possibly malicious code from over the Web cannot create major havoc. Introspection: The following command lists the sub-interpreters (\"slaves\") of the current interpreter: `% interp slaves` #### Ensembles Ensembles, (from Tcl 8.5 on), are commands that are composed out of sub-commands according to a standard pattern. Examples include Tcl\'s built-in chan and clock commands. Dispatching of subcommands, as well as informative error message for non-existing subcommands, is built-in. Subcommands are in a dict structure called \"-map\", with alternating name and action. Very simple example: `namespace ensemble create -command foo -map \`\ ` {bar {puts Hello} grill {puts World}}` creates a command foo that can be called like `% foo bar`\ `Hello`\ `% foo grill`\ `World`\ `% foo help`\ `unknown or ambiguous subcommand "help": must be foo, or bar` Obviously, ensembles are also a good base for implementing object orientation, where the command is the name of the objects, and the map contains its methods. Introspection: Serialize an ensemble\'s map with `namespace ensemble configure $name -map` #### Namespaces Namespaces are containers for procedures, non-local variables, and other namespaces. They form a tree structure, with the root at the global namespace named \"::\". Their names are built with :: as separators too, so ::foo::bar is a child of ::foo, which is a child of :: (similar to pathnames on Unix, where / is the separator as well as the root). In a nutshell, a namespace is a separate area, or scope, where procedures and variables are visible and private to that scope. To create a namespace, just evaluate some script (which may be empty) in it: `namespace eval ::foo {}` Now you can use it to define procedures or variables: `proc ::foo::test {} {puts Hello!}`\ `set ::foo::var 42` To get rid of a namespace (and clean up all its variables, procs, and child namespaces): `namespace delete ::foo` Introspection: `namespace children ::`\ `info var namespace::`\ `info commands namespace::` The following code gives an approximate size in bytes consumed by the variables and children of a Tcl namespace (of which ::, the global namespace, is of particular interest - all the (grand)\children are also added). If you call this proc repeatedly, you can observe whether data are piling up: `proc namespace'size ns {`\ ` set sum [expr wide(0)]`\ ` foreach var [info vars ${ns}::] {`\ ` if {[info exists $var]} {`\ ` upvar #0 $var v`\ ` if {[array exists v]} {`\ ` incr sum [string bytelength [array get v]]`\ ` } else {`\ ` incr sum [string bytelength $v]`\ ` }`\ ` }`\ ` }`\ ` foreach child [namespace children $ns] {`\ ` incr sum [namespace'size $child]`\ ` }`\ ` set sum`\ `}` Usage example: `% puts [namespace'size ::]`\ `179914` #### Threads Tcl users have traditionally been skeptical about threads (lightweight concurrent sub-processes) - the event loop model has proved pretty powerful, and simpler to debug. Originally from Tk, the event loop has moved into Tcl and serves - fileevents (more on channels than real files) - timed events - UI events (mouse or keyboard actions by the user) However, there is a growing tendency to enable threads in Tcl builds. The underlying model is that every thread runs in an interpreter of its own, so it is mostly encapsulated from the rest of the world. Communication between threads must be done with explicit methods. ### Packages and extensions Packages are Tcl\'s recommended way to modularize software, especially supportive libraries. The user most often uses the command `package require name ?version?` One can write packages in pure Tcl, or as wrappers for extensions which come with one or more compiled shared libraries (plus optionally one or more Tcl scripts). Popular extensions are: - BWidget (adds useful widgets to Tk - more below) - Expect (supports remote execution over networks) - Img (adds support of additional image file formats to Tk) - snack (sound input/output) - Snit (OO extension, with support for \"megawidgets\" in Tk) - sqlite (a tiny yet powerful SQL database) - tcllib (a collection of pure-Tcl packages - see below) - TclOO (the canonical object-orientation extension from 8.5) - tcltcc (a built-in C compiler - see below) - TclX (collection of system-related extensions, like signal handling) - tdom (XML parser, SAX or DOM, with XPath query support) - Tk (the cross-platform GUI toolkit, see below) - tkcon (a vastly extended console) - XOTcl (advanced dynamic OO extension) #### A little example package The following script creates the trivial but educational package futil, which in a namespace of the same name implements two procs for reading and writing complete text files, and the little introspection helper function, futil::?. The command to register the package (package provide) is executed only after all went well - this way, buggy source code, which raises an error during package require, will not be registered. (Other bugs you\'d have to spot and fix for yourself\...) Common Tcl distribution practice has the good habit of profound testing, typically in a separate test directory. On the other hand, including a self-test in the same file with the code makes editing easier, so after the package provide comes a section only executed if this file is sourced as a top- level script, which exercises the commands defined in futil. Whether the string read should be equal to the string written is debatable - the present implementation appends \\n to the string if it doesn\'t end in one, because some tools complain or misbehave if they don\'t see a final newline. If the tests do not run into an error either, even the required construction of a package index is fired - assuming the simplified case that the directory contains only one package. Otherwise, you\'d better remove these lines, and take care of index creation yourself. A script that uses this package will only have to contain the two lines `lappend ::auto_path ``<directory of this file>`{=html}\ `package require futil` You can even omit the first line, if you install (copy) the directory with the source and pkgIndex.tcl below \${tcl_install_directory}/lib. } `namespace eval futil {`\ ` set version 0.1`\ `}` But now back to the single script that makes up the package (it would make sense to save it as futil.tcl). We provide a read and a write function in the futil namespace, plus a little introspection function ? that returns the names of available functions: `proc futil::read {filename} {`\ ` set fp [open $filename]`\ ` set string [::read $fp] ;# prevent name conflict with itself`\ ` close $fp`\ ` return $string`\ `}`\ `proc futil::write {filename string} {`\ ` set fp [open $filename w]`\ ` if {[string index $string end]!="\n"} {append string \n}`\ ` puts -nonewline $fp $string`\ ` close $fp`\ `}`\ `proc futil::? {} {lsort [info procs ::futil::]}`\ `# If execution comes this far, we have succeeded ;-)`\ `package provide futil $futil::version` `#--------------------------- Self-test code`\ `if {[info ex argv0] && [file tail [info script]] == [file tail $argv0]} {`\ ` puts "package futil contains [futil::?]"`\ ` set teststring {`\ ` This is a teststring`\ ` in several lines...}`\ ` puts teststring:'$teststring'`\ ` futil::write test.tmp $teststring`\ ` set string2 [futil::read test.tmp]`\ ` puts string2:'$string2'`\ ` puts "strings are [expr {$teststring==$string2? {}:{not}}] equal"`\ ` file delete test.tmp ;# don't leave traces of testing` ` # Simple index generator, if the directory contains only this package`\ ` pkg_mkIndex -verbose [file dirn [info scr]] [file tail [info scr]]`\ `}` #### Tcllib Tcllib is a collection of packages in pure Tcl. It can be obtained from sourceForge, but is also part of ActiveTcl. The following list of contained packages may not be complete, as Tcllib is steadily growing\... - aes - Advanced Encryption Standard. - asn - asn.1 BER encoder/decoder - http/autoproxy - code to automate the use of HTTP proxy servers - base64 - Base64 encoding and decoding of strings and files. - bee - BitTorrent serialization encoder/decoder. - bibtex - Neil Madden\'s parser for bibtex files. Not fully complete yet, therefore not set for installation. - calendar - Calendar operations (see also tcllib calendar module). - cmdline - Various form of command line and option processing. - comm - Socket based interprocess communication. Emulates the form of Tk\'s send command. - control - procedures for tcl flow structures such as assert, do/until, do/while, no-op - counter - procedures for counters and histograms - crc - Computation of various CRC checksums for strings and files. - csv - manipulate comma separated value data - des - Data Encryption Standard. ::DES::des (not yet installed) - dns - interact with the Domain Name Service. <dns::address>, <dns::cleanup>, <dns::cname>, <dns::configure>, <dns::name>, <dns::reset>, <dns::resolve>, <dns::status>, <dns::wait>, - doctools - System for writing manpages/documentation in a simple, yet powerful format. - exif - exif::analyze exif::fieldnames - fileutil - Utilities for operating on files, emulating various unix command line applications (cat, find, file(type), touch, \...). - ftp - Client side implementation of FTP (File Transfer Protocol). In dire need of a rewrite. - ftpd - Server side implementation of FTP - grammar_fa - Operations on finite automatons. - html - generate HTML from a Tcl script. html::author, html::author, html::bodyTag, html::cell, html::checkbox, html::checkSet, html::checkValue, html::closeTag, html::default, html::description, html::description, html::end, html::eval, html::extractParam, html::font, html::for, html::foreach, html::formValue, html::getFormInfo, html::getTitle, html::h, html::h1, html::h2, html::h3, html::h4, html::h5, html::h6, html::hdrRow, html::head, html::head, html::headTag, html::if, html::init, html::init, html::keywords, html::keywords, html::mailto, html::meta, html::meta, html::minorList, html::minorMenu, html::openTag, html::paramRow, html::passwordInput, html::passwordInputRow, html::radioSet, html::radioValue, html::refresh, html::refresh, html::row, html::select, html::selectPlain, html::set, html::submit, html::tableFromArray, html::tableFromList, html::tagParam, html::textarea, html::textInput, html::textInputRow, html::title, html::title, html::urlParent, html::varEmpty, html::while, - htmldoc - This is not a true module but the place where tcllib 1.3 installed the tcllib documentation in HTML format. - htmlparse - procedures to permit limited manipulation of strings containing HTML. ::htmlparse::parse, ::htmlparse::debugCallback, ::htmlparse::mapEscapes, ::htmlparse::2tree, ::htmlparse::removeVisualFluff, ::htmlparse::removeFormDefs, - ident - RFC 1413 ident client protocol implementation - imap4 - currently undocumented code for interacting with an IMAP server - inifile - code to manipulate an initialization file. ::ini::open, ::ini::close, ::ini::commit, ::ini::sections, ::ini::keys, ::ini::value - dns/ip - Manipulation of IP addresses. ::ip::version, ::ip::is, ::ip::normalize, ::ip::equal, ::ip::prefix - irc - Internet Relay Chat procedures. <irc::config>, <irc::connection>, - javascript - generate Javascript for including in HTML pages. <javascript::BeginJS>, <javascript::EndJS>, <javascript::MakeMultiSel>, <javascript::MakeClickProc>, <javascript::makeSelectorWidget>, <javascript::makeSubmitButton>, <javascript::makeProtectedSubmitButton>, <javascript::makeMasterButton>, <javascript::makeParentCheckbox>, <javascript::makeChildCheckbox> - jpeg - edit comment blocks, get image dimensions and information, read exif data of images in the JPG format - ldap - Client side implementation of LDAP (Lightweight Directory Access Protocol). - log - general procedures for adding log entries to files ::log::levels, ::log::logMsg, ::log::lv2longform, ::log::lv2color,::log::lv2priority, - logger - ::logger::walk, ::logger::services, ::logger::enable, ::logger::disable (part of the log module) - math - general mathematical procedures. ::math::calculus, ::math::combinatorics, ::math::cov, ::math::fibonacci, ::math::integrate, ::math::interpolate, ::math::max, ::math::mean, ::math::min, ::math::optimize, ::math::product, ::math::random, ::math::sigma, ::math::statistics, ::math::stats, ::math::sum - md4 - ::md4::md4, ::md4::hmac, ::md4::MD4Init, ::md4::MD4Update, ::md4::MD4Final - md5 - \[fill in the description of this module\] ::md5::md5, ::md5::hmac, ::md5::test, ::md5::time, ::md5::\<\<\< - md5crypt - ::md5crypt::md5crypt, ::md5crypt::aprcrypt - mime - ::mime::initialize, ::mime::parsepart, ::mime::finalize, ::<smtp::sendmessage> - multiplexer - \[fill in the external interfaces\] - ncgi - procedures for use in a CGI application. ::ncgi::reset, ::ncgi::urlStub, ::ncgi::urlStub - nntp - routines for interacting with a usenet news server. ::<nntp::nntp>, ::<nntp::NntpProc>, ::<nntp::NntpProc>, ::<nntp::okprint>, ::<nntp::message>, - ntp - network time protocol procedure ::ntp::time - png - edit comment blocks, get image dimensions and information for Portable Network Graphics format. - pop3 - Post Office Protocol functions for reading mail from a pop3 server. ::pop3::open, ::pop3::close, ::pop3::status, - pop3d - Post Office Protocol Server. pop3d::new - profiler - ::profiler::tZero, ::profiler::tMark, ::profiler::stats, ::profiler::Handler, ::profiler::profProc, ::profiler::init - rc4 - stream encryption. ::rc4::rc4 - report - format text in various report styles. ::report::report , ::report::defstyle, ::report::rmstyle, - sha1 - ::sha1::sha1, ::sha1::hmac - smtpd - ::smtpd::start, ::smtpd::stop, ::smtpd::configure, ::smtpd::cget - snit - Snit\'s Not Incr Tcl - OO package. Delegation based. ::snit::type, ::snit::widget, ::snit::widgetadaptor - soundex::knuth - string matching based on theoretical sound of the letters - stooop - OO package. stooop::class, stooop::virtual, stooop::new, stooop::delete, stooop::classof - struct1 - Version 1 of struct (see below), provided for backward compatibility. : : struct::list, ::struct::graph, ::struct::matrix, ::struct::queue, ::struct::stack, ::struct::Tree, ::struct::record, ::struct::skiplist, ::struct::prioqueue, new: ::struct::sets - tar - untar, list, and stat files in tarballs and create new tarballs - textutil - Utilities for working with larger bodies of texts. textutil::expand - the core for the expand macro processor. - tie - Persistence for Tcl arrays. - treeql - Tree Query Language, inspired by COST. - uri - Handling of uri/urls (splitting, joining, \...) - uuid - Creation of unique identifiers. #### TclOO TclOO is a loadable package to provide a foundation for object orientation, designed so that specific OO flavors like Itcl, Snit, or XOTcl can build on it. But it\'s a usable OO system in itself, offering classes, multiple inheritance, mixins and filters. Here is some example code to give you an impression: `#!/usr/bin/env tclsh85`\ `package require TclOO`\ `namespace import oo::`\ `class create Account {`\ ` constructor { {ownerName undisclosed}} {`\ ` my variable total overdrawLimit owner`\ ` set total 0`\ ` set overdrawLimit 10`\ ` set owner $ownerName`\ ` }`\ ` method deposit amount {`\ ` my variable total`\ ` set total [expr {$total + $amount}]`\ ` }`\ ` method withdraw amount {`\ ` my variable {}[info object vars [self]] ;# "auto-import" all variables`\ ` if {($amount - $total) > $overdrawLimit} {`\ ` error "Can't overdraw - total: $total, limit: $overdrawLimit"`\ ` }`\ ` set total [expr {$total - $amount}]`\ ` }`\ ` method transfer {amount targetAccount} {`\ ` my variable total`\ ` my withdraw $amount`\ ` $targetAccount deposit $amount`\ ` set total`\ ` }`\ ` destructor {`\ ` my variable total`\ ` if {$total} {puts "remaining $total will be given to charity"}`\ ` }`\ `}` #### tcltcc Tcltcc is a loadable package that wraps the Tiny C compiler (tcc) for use with Tcl. It can be used to - compile C code directly to memory - produce dynamic loadable libraries (DLLs) or executable files. Convenience functions generate wrapper code, so that the user needs only write the really substantial C code. Examples:* Wrap a C function into a Tcl command \"on the fly\" (here shown in an interactive session): `% package require tcc`\ `0.2`\ `% namespace import tcc::`\ `% cproc sigmsg {int i} char {return Tcl_SignalMsg(i);} `\ `% sigmsg 4`\ `illegal instruction` Produce a DLL with a fast implementation of Fibonacci numbers: `% set d [tcc::dll]`\ `% $d ccode {`\ ` static int fib(int n) {return n <= 2? 1 : fib(n-1) + fib(n-2);}`\ ` }`\ `% $d cproc fiboy {int n} int {return fib(n);}`\ `% $d write -name fiboy`\ `% load fiboy[info sharedlibextension]`\ `% fiboy 20`\ `6765` Produce a tclsh with an extra square command: `% set code [tcc::wrapCmd square {double x} double x_square {return xx;}]`\ `% append code {`\ ` int AppInit(Tcl_Interp interp) {`\ ` int rc;`\ ` rc = Tcl_CreateObjCommand(interp,"square",x_square,NULL,NULL);`\ ` return Tcl_Init(interp);`\ ` }`\ ` int main(int argc, char argv[]) {`\ ` Tcl_Main(argc, argv, AppInit);`\ ` return 0;`\ ` }`\ `}`\ `% tcc $::tcc::dir exe t`\ `% t add_file $::tcc::dir/c/crt1.c`\ `% t add_library tcl8.5`\ `% t compile $code`\ `% t output_file mytclsh.exe`\ `% exec mytclsh.exe {<<puts [square 5]}`\ `25.0` Tcltcc is open source, LGPL licensed, available at <http://code.google.com/p/tcltcc/> . The full functionality is at the current early stage (October 2007) only available on Windows 95/XP platforms, but in-memory compilation works on Linux too. #### tDOM tDOM is a popular extension for XML/HTML processing, allowing both SAX-style \"on-the-fly\" parsing and the DOM approach of representing a whole XML element in memory. Here is an example of a SAX-style application. The expat* parser that comes with tDOM is instrumented with callbacks for element start, character data, and processing instructions. Elements, attributes, characters and processing instructions are counted, plus a tally for each element type is done. ``` tcl #!/usr/bin/env tclsh package require tdom #--- Callbacks for certain parser events proc el {name attlist} { global g incr ::nEl incr ::nAtt [llength $attlist] inc g($name) } proc ch data { incr ::nChar [string length $data] } proc pi {target data} { incr ::nPi } proc inc {varName {increment 1}} { upvar 1 $varName var if {![info exists var]} {set var 0} incr var $increment } #--- "main" loop if ![llength $argv] {puts "usage: $argv0 file..."} foreach file $argv { foreach i {nEl nAtt nChar nPi} {set $i 0} ;# reset counters array unset g set p [expat -elementstartcommand el \ -characterdatacommand ch \ -processinginstructioncommand pi ] if [catch {$p parsefile $file} res] { puts "error:$res" } else { puts "$file:\n$nEl elements, $nAtt attributes, $nChar characters,\ $nPi processing instructions" foreach name [lsort [array names g]] { puts [format %-20s%7d $name $g($name)] } } $p free } ```