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This page surveys information about quality of life in the developing world. The purpose is primarily to answer the question, “If a donor’s funds save a live, what sort of life is saved?”
We make no attempt to fully convey what life is like; instead, we focus on what facts are available from relatively broad, large-sample, plausibly representative studies. We restrict ourselves to basic questions such as “What health problems are common and how common are they?”, or “What problems do people in the developing world generally list as particularly important?”
For someone seeking a more qualitative (and less representative) picture, we suggest a visit to the developing world.
- Income and self-reported well-being
- Income and assets
- Mortality and Morbidity: what are the major health problems in the developing world?
- What problems do people in the developing world believe are most pressing?
- Self-reported life satisfaction: People in poor countries report that they are on average less satisfied with their lives than people in rich countries. The average resident of a low-income country rated their satisfaction as 4.3 using a subjective 1-10 scale, while the average was 6.7 among residents of G8 countries. We interpret this as a large satisfaction gap.
- Incomes: A large proportion of the population in developing countries live on under $1 or $2 per day. The poor spend a large proportion of their incomes on food, may lack access to basic infrastructure, and own few productive assets. However, they do make consumption choices that involve spending on things other than food and use a variety of instruments to manage erratic income streams. Ownership of televisions and radios and access to electricity and sanitation varies widely.
- Mortality: On one hand, people in Sub-Saharan Africa are much worse off, and much more likely to die prematurely, than people in wealthier parts of the world. On the other hand, those who live past the age of 5 have strong chances of living to age 60 or so; saving a life even from a single cause of death means saving a person who is likely to live quite a while longer.
- Morbidity: A third of children under five in developing countries show evidence of long-term malnutrition. Malnutrition can cause low energy, diarrhea, anemia, hypothyroidism, poor vision, and pneumonia, as well as increased susceptibility to many other diseases. Prevalence of parasitic worm infection is very high in many poor regions. Malaria causes frequent sickness among children under 5, who average over 4 days of sickness with the disease per year.
- Development Priorities: Sub-Saharan Africans rank reducing poverty and hunger as the two most pressing Millennium Development Goals. Health goals are also prioritized.
Income and self-reported well-being
Are people in poor countries less satisfied with their lives?
The Gallup World Poll asks a representative sample of people from 132 countries to answer questions about their well-being. Examples include asking respondents to rank their life satisfaction on a scale from 0 to 10 and to answer the question "are you satisfied or dissatisfied with your personal health?" This data has been used to look at the relationship between level of economic development (income, health status, etc.) and self-reported well-being.1
The 2006 Gallup World Poll data shows a positive correlation between per capita income in a country and average self-reported life satisfaction. One report on the World Poll data concluded, "high-income countries have greater life satisfaction than low-income countries...there is no evidence that the cross-country effects of greater income fade out or vanish as countries increase their income."2
In the chart below, average life satisfaction (as measured by the Gallup World Poll) is plotted against income for the 38 of the 43 low-income economies (as classified by the World Bank)3 for which World Poll data is available, as well as for the members of the G8.4 Relatively high-income countries report satisfaction levels between 6 and 8 (on a scale from 0 to 10); low-income countries report satisfaction levels between 3 and 5.5.
The difference between satisfaction in the average low-income country and the average G8 country is about 2.4, or a little less than a quarter of the scale (which ranges from 0 to 10, with 0 representing the worst possible life and 10 representing the best possible life).
Income and assets
Global poverty rates
Poverty rates have been decreasing in many parts of the world, but the number of people living below the international poverty line remains high, especially in Sub-Saharan Africa.5 Data on the number of people living on less than $1.25 per day (the international standard of extreme poverty)6 and on less than $2.00 per day (another international poverty benchmark) is based on dissimilar national studies from a limited number of countries,7 and thus should be approached with caution. Recent World Bank data estimates the number of people living on under $1.25 a day at about 1.4 billion worldwide.8 About half of Sub-Saharan Africans live on under $1.25 a day.9 Many more live just above this line. Over 2.5 billion people live on less than $2 a day, with nearly three-quarters of the population of Sub-Saharan Africa falling into this category.10 (Note: These figures are calculated for purchasing power parity (PPP), meaning that someone earning "$2 a day" does not literally earn this much but the equivalent of what 2 U.S. dollars could buy in the United States.11)
What does it mean to live on under 1 or 2 dollars per day?
Most of the points below are taken from analysis by Abhijit Banerjee and Esther Duflo of survey data from 13 countries.12 We also consider information from Portfolios of the Poor,13 which tracked the financial lives of over 250 households in 3 countries at a high level of detail.
- Most of income is spent on food. People living on less than $1 or $2 per day reported spending a large proportion (between 55 and 80%) of their incomes on food. The proportion of income spent on food was not substantially different between the under $1 and under $2 per day groups.14
- There is little ownership of "productive assets." People living on under $1 a day generally reported owning few “productive” assets such as bicycles, sewing machines, phones, or tractors,15 though in some areas a large proportion of poor households own small plots of land.16
- Varying ownership of TV and radios. Ownership of non-productive assets also varied widely across countries and between urban and rural areas. In Tanzania, for example, almost no one living on under $1 a day reported owning a television, while 57% of those living on the same (adjusted) income in Hyderabad, India owned one. Rates of radio ownership were higher than those for television. About 70% of those living on under $1 a day in Peru, South Africa, and Nicaragua own radios, and in several other places ownership rates were over 40%.17
- Varying access to electricity, water and sanitation. The poor often lacked access to basic infrastructure, and as with assets, there was large variability among households around the world. In Mexico and Indonesia, for example, electricity access was nearly universal, but in-house tap water and ownership of a toilet or latrine were far less prevalent in Indonesia (data for Mexico not available). In Tanzania, the pattern was quite different: nearly every poor household owned a toilet and very few had access to electricity or in-house tap water.18
A poor urban community in Cape Town, South Africa with access to electricity but without household latrines or in-house tap water.
- Poor health. The poor reported often being sick. Among the surveys cited by Banerjee and Duflo (2006), no surveys yielded an average 'percent of household members sick' (in the month before the survey) of below 10%, and many reported rates above 25%.19
- Multiple occupations. Banerjee and Duflo (2006) also looked into how the poor earn their incomes. One pattern they found in many parts of the world was the tendency of the poor to engage in multiple occupations. Common occupations were running very small businesses, small-plot agriculture, and day labor.20 The authors argue that by spreading themselves across a variety of occupations and operating their businesses at such small scales, the poor miss out on gains from specialization and scale economies.21 They believe that this poverty-perpetuating behavior comes from the desire of the poor to minimize risk as well as their inability to raise the capital needed to operate more efficiently.22
- Unpredictability and risk. Banerjee and Duflo (2007) argue that what often separates the 'middle class' (which they define as living on between $2 and $10 per day) from the poor in developing countries are steady well-paying jobs, not greater success at running small businesses.23 Banerjee and Duflo hypothesize that more reliable income flows may be the reason the middle class invest more of their income in the future than the poor do.24 (However, we note that it is also possible that, to some degree, people who are more future-oriented in general are the same people who end up with higher incomes.)
Portfolios of the Poor suggests that in addition to having small incomes, the poor often have irregular and unpredictable incomes.25 The book reports on Collins, et al.'s studies of how the poor in India, Bangladesh, and South Africa manage the fact that "the reality of living on two dollars a day is that you don’t literally earn that sum each day."26
Mortality and Morbidity: what are the major health problems in the developing world?
On one hand, people in low-income countries are much worse off, and much more likely to die prematurely, than people in wealthier parts of the world. On the other hand, it's important to note that those who live past age 5 have strong chances of living to age ~60; saving a life from even a single cause of death means saving a person who is likely to live significantly longer.27
Children under 5 in low-income countries primarily die of preventable and treatable diseases such as malaria, respiratory infections, diarrhea, perinatal conditions, measles, and HIV/AIDS. Between ages 5 and 60, the major causes of death in low-income countries (relative to higher-income countries) are HIV/AIDS, tuberculosis, and maternal mortality (i.e., deaths in childbirth). After age 60, there are large differences in the mortality rates for many of the same causes of death that affect those under 5, as well as for many conditions that require advanced medical attention (heart disease, cancer, diabetes).28
The table below shows the differences between low-income and high-income countries, in terms of deaths per 1,000, by age range and cause of death. It is color-coded: yellow squares represent causes of death for which mortality rates are greater in low-income countries by at least 0.5 deaths per 1,000 people, orange squares represent causes of death for which mortality rates are greater in low-income countries by at least 1 deaths per 1,000 people), and red squares represent causes of death for which mortality rates are greater in low-income countries by at least 2.5 deaths per 1,000 people.29
Note that conditions vary within the developing world. Mortality rates for many causes are higher in Sub-Saharan Africa than in the group of low-income countries (which includes some highly populous Asian countries, such as India, Pakistan, and Bangladesh). For more information, see our discussion of life expectancy in Sub-Saharan Africa.
Non-fatal health problems
Household surveys of those living on under $1 or $2 per day show that the poor are often sick. In the surveys cited by Banerjee and Duflo (2006), in every country for which data was available an average of over 10% of households reported at least one member needed to see a doctor in the month prior to the survey. In many areas the average exceeded 25%; parts of India, Mexico, and Nicaragua had averages above 35%.30 Here we do not discuss all health problems in detail, but we present three prevalent conditions (malnutrition, parasitic worms, and malaria) which are both direct causes of symptoms and risk factors for other conditions. In addition, we present data on the prevalence of a selection of health problems that are common in low-income countries and compare prevalence rates in these countries to rates in high-income countries.
Malnutrition is a widespread problem in the developing world. It is estimated that in 2000-2002, over 800 million people in the developing world were undernourished (insufficient energy intake),31 and 2 billion are micronutrient deficient.32 In 2005, approximately 32% of children under five in developing countries were stunted (had a height-for age that was more than two standard deviations below the global average), which likely reflects chronic undernutrition throughout life.33 Malnourishment may be both caused by disease (such as parasitic worms) and increase susceptibility to disease.34 Lacking certain nutrients has been associated with a wide range of health problems including low energy, diarrhea, anemia, hypothyroidism, poor vision, and pneumonia.35 We do not know how common or severe these symptoms generally are among malnourished people.
Malnutrition is sometimes associated with infection with parasitic worms.36 It is estimated that there are more than 1.2 billion roundworm infections globally, ~700-800 million infections with each hookworm and whipworm, and 250 million infections with schistosomiasis.37 While most infections do not cause symptoms,38 heavy worm infection can cause anemia, dysentery, and growth retardation.39 In the long run, worm infection "impair[s] physical and mental growth in childhood, thwart[s] educational advancement, and hinder[s] economic development."40 Death from worm infection can occur, but is fairly rare.41 (More on specific types of infections at our discussion of schistosomiasis and our discussion of soil-transmitted helminths.)
Another major cause of disability and suffering is malaria. The Disease Control Priorities Project estimates that there were 213 million cases of malaria in 2000, resulting in over 1.1 million deaths.42 This means that while malaria is a leading cause of death, the vast majority of cases are not fatal, but do cause suffering and disability. Like many other diseases, risk of malaria infection and complications are increased by malnutrition.43 As can be seen in the chart here, children under five average over 4 days of sickness with malaria per year, and older children fall sick every 2-3 years for an average of 2.3 days. Uncomplicated malaria is characterized by fever, headaches, and nausea.44 Severe malaria can cause cognitive impairment, seizures, coma, respiratory distress, and heart problems.45
Other conditions. The table below compares prevalence rates for a selection of additional common causes of morbidity in low-income countries. Prevalence rates in high-income countries and for HIV/AIDS are included for comparison purposes.
While prevalence rates are generally higher in low-income than in high-income countries (except for asthma and hearing loss), these conditions, aside from anemia and schistosomiasis, are rare across low-income countries. For many of the infectious conditions, endemic areas may exist where large proportions of the population suffer from the disease, but the average person in the developing world is unlikely to be suffering from these diseases.46
|% affected in low-income countries||% affected in high income countries||Who is affected?|
|Anemia||Mostly women and young children.47|
|Schistosomiasis||Primarily affects the poor.48|
|Vision impairment||Primarily affects those over 40. Higher prevalence in poor areas.49|
|Hearing loss||About a quarter of severe cases affect children.50|
|Lymphatic filariasis||Prevalence increases with age. Disproportionately affects the poor.51|
|HIV/AIDS||Primarily affects adults. About 8% of HIV infections are among children.52|
|Vitamin A deficiency||More likely to affect the poor as it results from lack of meat product, fruit and vegetable, and fat consumption.53|
|Trachoma||Primarily affects young children and adult women.54|
|Onchocerciasis||Intensity increases with age.55|
What problems do people in the developing world believe are most pressing?
In 2006, the Gallup World Poll asked a representative sample from 26 Sub-Saharan Africa countries to rank the Millennium Development Goals (MDGs) in order of importance to them.56 The MDGs are a set of targets established by the United Nations in 2000 on a range of human development goals including poverty, education, health, gender equality, and the environment.57 Respondents consistently ranked reducing poverty and reducing hunger as the two most important goals.58 Health goals followed the top two, with 'Reducing the spread of HIV' ranking third and reducing under five mortality, maternal mortality and 'Reducing the spread of malaria and TB' coming in at 5, 6, and 8, respectively, out of a total of 12 goals. One argument for why health goals are not ranked higher than they are, argued by Deaton (2008), is that Africans report being more satisfied with their health than we might expect because they are more used to being sick.59
The youth-focused goals of 'Providing more jobs for youths' and 'Achieving primary education for all' were also considered important by many respondents and were ranked 4 and 7, respectively. The goals of improving access to clean water and sanitation, achieving gender equality, and increasing access to new technology were least important to those surveyed.60
Each respondent was asked to rank order six of the twelve goals. A value of 1 was assigned to the top-ranked goal, through 6 for the lowest-ranked goal. Thus the averages below fall in the range of 1 to 6.
|Millennium Development Goal||Weighted Average Score|
|Reducing the spread of HIV/AIDS||3.05|
|Providing more jobs for youth||3.17|
|Reducing the death rate among children under five||3.34|
|Reducing the number of women dying during childbirth||3.38|
|Achieving primary education for all||3.62|
|Reducing the spread of malaria and TB||3.64|
|Improving access to safe drinking water||3.75|
|Improving access to sanitation facilities||4.09|
|Achieving gender equality and empowering women||4.38|
|Providing access to new technology||4.65|
There were few differences in how men and women, urban and rural dwellers, employed and unemployed adults, or different age and education cohorts ranked the goals.61 Rankings did vary across countries and regions, but reducing hunger and poverty were the top two goals for all but 6 of the 26 countries polled. Of these six, four were Southern African countries where HIV prevalence is very high; all four ranked 'Reducing the spread of HIV' as their top priority. Kenya and Uganda also ranked this goal in their top two. Larger differences between countries were seen in rankings of lower priority goals.62
- Awasthi, Shally , D. A. P. Bundy, and Lorenzo Savioli. 2003. Helminthic infections. British Medical Journal 327: 431-433.
- Banerjee, Abhijit, and Esther Duflo. 2006. The economic lives of the poor (PDF).
- Banerjee, Abhijit, and Esther Duflo. 2007. What is middle class about the middle classes around the world? (PDF).
- Black, Robert E., et al. 2008. Maternal and child undernutrition: Global and regional exposures and health consequences. Lancet 371: 243–60.
- Centers for Disease Control and Prevention. Malaria: Disease. http://www.cdc.gov/malaria/about/disease.html (accessed April 27, 2010). Archived by WebCite® at http://www.webcitation.org/5pIz0gCDp.
- Collins, Daryl, et al. 2009. Portfolios of the poor: How the world's poor live on $2 a day. Princeton, NJ: Princeton University Press. Selections at http://books.google.com/books?id=KE0H8B7NBNYC&lpg=PP1&dq=portfolios%20of... (accessed April 29, 2010).
- de Silva, Nilanthi R., et al. 2003. Soil-transmitted helminth infections: Updating the global picture. Trends in Parasitology 19: 547-551.
- Deaton, Angus. 2008. Income, health, and well-being around the world: Evidence from the Gallup World Poll (PDF). Washington, DC: Gallup.
- Edwin, Michael. 2000. The population dynamics and epidemiology of lymphatic filariasis. In Lymphatic filariasis, ed. Thomas B. Nutman, 41-81. London: Imperial College Press.
- Food and Agriculture Organization of the United Nations. Glossary (list). http://faostat.fao.org/site/375/default.aspx (accessed June 10, 2010). Archived by WebCite® at http://www.webcitation.org/5qNmnFEfJ.
- GiveWell. Mortality by income group with calculations (XLS).
- Global Network for Neglected Tropical Diseases. 2009. Trachoma (PDF).
- Jamison, Dean T., et al., eds. 2006. Disease control priorities in developing countries (PDF). 2nd ed. New York: Oxford University Press.
- Kumaraswami, V. 2000. The clinical manifestations of lymphatic filariasis. In Lymphatic filariasis, ed. Thomas B. Nutman, 103-125. London: Imperial College Press.
- Lopez, Alan D., et al., eds. 2006. Table 3B.7: Deaths by cause, sex, and age in the Sub-Saharan Africa region, 2001 (thousands). In Global burden of disease and risk factors. New York: Oxford University Press. http://www.dcp2.org/pubs/GBD/3/Table/3.B7 (accessed April 27, 2010). Archived by WebCite® at http://www.webcitation.org/5pIf0sYLp.
- Lopez, Alan D., et al., eds. 2006. Table 3B.8: Deaths by cause, sex, and age in high-income countries, 2001 (thousands). In Global burden of disease and risk factors. New York: Oxford University Press. http://www.dcp2.org/pubs/GBD/3/Table/3.B8 (accessed April 27, 2010). Archived by WebCite® at http://www.webcitation.org/5pIf1qxjx.
- Mathers, Colin D., Majid Ezzati, and Alan D. Lopez. 2007. Measuring the burden of neglected tropical diseases: The global burden of disease framework (PDF). PLoS Neglected Tropical Diseases 1, no. 2.
- Müller, Olaf, and Michael Krawinkel. 2005. Malnutrition and health in developing countries (PDF). Canadian Medical Association Journal 173: 279-286.
- Olds, Richard G. 1998. Infections caused by helminths. In Internal medicine. 5th ed. Ed. Jay H. Stein, 1696-1706. St. Louis: Mosby.
- Simonsen, Paul E. 2009. Filariases. In Manson’s tropical diseases. 22nd ed. Ed. Gordon C. Cook and Alimuddin I. Zumla, 1477-1513. London: Saunders.
- Tortora, Robert D. 2009. Sub-Saharan Africans rank the Millennium Development Goals (MDGs) (PDF). Washington, DC: Gallup.
- UNAIDS. 2007. AIDS epidemic update (PDF).
- World Bank. 2006. World Development Indicators 2006. Washington, DC: World Bank.
- World Bank. 2008. Poverty data: A supplement to World Development Indicators 2008 (PDF). Washington, DC: World Bank.
- World Bank. Country and lending groups: Low income economies. http://data.worldbank.org/about/country-classifications/country-and-lend... (accessed May 26, 2010). Archived by WebCite® at http://www.webcitation.org/5pHSuWN38.
- World Health Organization. Disease and injury regional estimates for 2004: Deaths for World Bank income groups (XLS).
- World Health Organization. Disease and injury regional estimates for 2004: Prevalence for World Bank income groups (XLS).
"Here I focus on the life satisfaction question about life at the present time, measured on an 11-point scale from 0 (“the worst possible life”) to 10 (“the best possible life”), and the health satisfaction question (“are you satisfied or dissatisfied with your personal health?”). I look at how the answers to these questions vary with age and with the objective circumstances of the country, particularly the levels and rates of change of per capita income and life expectancy." Deaton 2008, Pg 2.
Deaton 2008, Pg 3.
For classification, see World Bank, "Country and Lending Groups: Low Income Economies."
"Global poverty measured at the $1.25 a day line has been decreasing since the 1980s. the number of people living in extreme poverty fell from 1.9 billion in 1981 to 1.8 billion in 1990 to about 1.4 billion in 2005 (figure 6). this substantial reduction in extreme poverty over the past quarter century, however, disguises large regional differences...The poverty rate fell only slightly in Sub-Saharan Africa—going from 54 percent in 1981 to 59 percent in 1999 then down to 51 percent in 2005. But the number of people living below the poverty line has nearly doubled." World Bank 2008, Pg 10.
"The $1.25 a day poverty line measured in 2005 prices replaces the $1.08 a day poverty line measured in 1993 prices. often described as “$1 a day,” $1.08 has been widely accepted as the international standard for extreme poverty and was incorporated in the first of the Millennium Development Goals." World Bank 2008, Pg 1.
"Data coverage is improving in all regions, but Sub-Saharan Africa continues to lag, with only 28 of 48 countries having at least one data set available...Household surveys can differ widely, for example, in the number of consumer goods they identify. And even similar surveys may not be strictly comparable because of differences in timing or the quality and training of survey enumerators." World Bank 2006, Pg 74.
People living on less than 2005 PPP $1.25 a day (millions) - Total: 1,374.
Data from World Bank 2008, Pg 11, Table 3.
Share of people living on less than 2005 PPP $1.25 a day (%) - sub-Saharan Africa: 50.9%.
Data from World Bank 2008, Pg 11, Table 3.
Share of people living on less than 2005 PPP $2.00 a day (%) - sub-Saharan Africa: 72.9%.
People living on less than 2005 PPP $2.00 a day (millions) - Total: 2,564.
Data from World Bank 2008, Pg 11, Table 3.
"PPP can be defined as the number of units of a country’s currency needed to buy the same amount of goods and services in that country as one U.S. dollar would buy in the United States." World Bank 2008, Pg 2.
"Our discussion of the economic lives of the extremely poor builds on household surveys conducted in 13 countries listed in Table 1: Cote d’Ivoire, Guatemala, India, Indonesia, Mexico, Nicaragua, Pakistan, Panama, Papua New Guinea, Peru, South Africa, Tanzania, and Timor Leste. We mainly use the Living Standard Measurement Surveys (LSMS) conducted by the World Bank and the “Family Life Surveys” conducted by the Rand Corporation, all of which are publicly available. In addition, we also use two surveys that we conducted in India with our collaborators." Banerjee and Duflo 2006, Pg 2.
Collins et al. 2009.
Banerjee and Duflo 2006, Pg 32, Table 3.
“Apart from land, extremely poor households in rural areas tend to own very little by way of durable goods, including productive assets: 34 percent own a bicycle in Cote d’Ivoire, but less than 14 percent in Udaipur, Nicaragua, Panama, Papua New Guinea, Peru, and East Timor. In Udaipur, where we have detailed asset data, we find that most extremely poor households have a bed or a cot but only about 10 percent have a chair or a stool and 5 percent have a table. About half have a clock or a watch. Less than 1 percent has an electric fan, a sewing machine, a bullock cart, a motorized cycle of any kind, or a tractor. No one has a phone." Banerjee and Duflo 2006, Pg 8.
"Among productive assets, land is the one that many people in the rural surveys seem to own though there are [sic] enormous country-to-country variation." Banerjee and Duflo 2006, Pg 7.
Banerjee and Duflo 2006, Pg 33, Table 4.
Banerjee and Duflo 2006, Pg 34, Table 5.
Banerjee and Duflo 2006, Pg 36, Table 7. See Pgs 8-9 for what seems to be interpretations of Table 7.
"All over the world, a substantial fraction of the poor act as entrepreneurs in the sense of raising the capital, carrying out the investment, and being the full residual claimants for the earnings.... Many poor households have multiple occupations.... This pattern of multiple occupations is stronger in rural areas. In Udaipur district, as we discussed earlier, almost everybody owns some land and almost everybody does at least some agriculture. Yet only 19 percent of the households describe self-employment in agriculture as the main source of their income.... The most common occupation for the poor in Udaipur is working as a daily laborer." Banerjee and Duflo 2006, Pg 10-11.
“Poor families do seek out economic opportunities, but they tend not to get too specialized. They do some agriculture, but not to the point where it would afford them a full living (for example by buying/renting/sharecropping more land). They also work outside, but only in short bursts—they do not move permanently to their place of occupation.” Banerjee and Duflo 2006, Pg 12.
“Many of these businesses are probably operating at too small a scale for efficiency.” Banerjee and Duflo 2006, Pg 13.
“Risk spreading is clearly one reason why the poor, who might find risk especially hard to bear, tend not to be too specialized in any one occupation.” Banerjee and Duflo 2006, Pg 20.
"A final, more compelling reason for doing multiple jobs is that the poor cannot raise the capital they would need to run a business that would fully occupy them." Banerjee and Duflo 2006, Pg 20.
"Nothing seems more middle class than the fact of having a steady well-paying job. While there are many petty entrepreneurs among the middle class, most of them do not seem to be capitalists in waiting. They run businesses, but, for the most part, only because they are still relatively poor and every little bit helps." Banerjee and Duflo 2007, Pg 21.
"Perhaps the sense of control over the future that one gets from knowing that there will be an income coming in every month -- and not just the income itself—is what allows the middle class to focus on building their own careers and those of their children." Banerjee and Duflo 2007, Pg 21.
"Of all the commonalities [among the poor], the most fundamental is that the households are coping with incomes that are not just low, but also irregular and unpredictable." Collins et al. 2009, Pg 16.
Collins et al. 2009, Pg 17.
Data from World Health Organization, "Disease and Injury Regional Estimates for 2004: Deaths for World Bank Income Groups." Calculations in GiveWell, "Mortality by Income Group with Calculations."
- Lopez et al. 2006, Table 3B.7: Deaths by Cause, Sex, and Age in the Sub-Saharan Africa Region, 2001 (Thousands).
- Lopez et al. 2006, Table 3B.8: Deaths by Cause, Sex, and Age in High-Income Countries, 2001 (Thousands).
Data is from World Health Organization, "Disease and injury regional estimates for 2004: Deaths for World Bank income groups." All data and calculations are in GiveWell, "Mortality by income group with calculations."
"Detailed information on health is not available in all the surveys we have, but most report health episodes that left a household member bedridden for a day or more, or required them to see a doctor. While this data is less than perfect, given that the poor may be less prone to recall and report such sicknesses than the rich, the general pattern is of a remarkably high level of morbidity. Among the rural poor living under $1 a day in Peru, South Africa, East Timor, Panama, and Tanzania, between 11 and 15 percent of households report having a member either being bedridden for at least a day or requiring a doctor. The number is between 21 and 28 percent in Pakistan, Indonesia, and Cote d’Ivoire, and between 35 and 46 percent in Nicaragua, Udaipur, and Mexico." Banerjee and Duflo 2006, Pg 8-9. See Banerjee and Duflo 2006, Pg 36, Table 7 for full results.
"An estimated 852 million people were undernourished in 2000–2002, with most (815 million) living in developing countries." Müller and Krawinkel 2005, Pg 279.
Müller and Krawikel cite the Food and Agriculture Organization of the United Nations, which defines undernourishment on its website as "the condition of people whose dietary energy consumption is continuously below a minimum dietary energy requirement for maintaining a healthy life and carrying out a light physical activity." Food and Agriculture Organization of the United Nations, "Glossary (List)."
"Micronutrient deficiencies affect at least 2 billion people worldwide." Müller and Krawinkel 2005, Pg 282.
"One indicator to monitor progress for this target is the proportion of children who are underweight—ie, low weight compared with that expected for a well-nourished child of that age and sex. This anthropometric indicator can indicate wasting (ie, low weight-for-height, indicating acute weight loss), or much more commonly, stunting (ie, low height-for-age, indicating chronic restriction of a child’s potential growth)." Black et al. 2008, Pg 244.
"For all developing countries, an estimated 32% (178 million) of children younger than 5 years had a height-for-age Z score of less than –2 in 2005 (table 1)." Black et al. 2008, Pg 245.
"The high prevalence of bacterial and parasitic diseases in developing countries contributes greatly to malnutrition there." Müller and Krawinkel 2005, Pg 279.
"It is globally the most important risk factor for illness and death." Müller and Krawinkel 2005, Pg 279.
"Iron is an essential part of hemoglobin, myoglobin and various enzymes. Its deficiency thus leads mainly to anemia, but also to several other adverse effects. Lack of iodine reduces the production of thyroid hormone and increases that of thyroid-stimulating hormone. As a result, the thyroid gland becomes hyperplastic and goitrous, and hypothyroidism develops. Vitamin A deficiency contributes to anemia by immobilizing iron in the reticuloendothelial system, reducing hemopoiesis and increasing susceptibility to infections. Vitamin A is essential for the functioning of the eyes as well as the immune system.... Zinc deficiency is a major determinant for diarrhea and pneumonia." Müller and Krawinkel 2005, Pg 283.
"Heavy burdens of both roundworm and whipworm are associated with protein energy malnutrition." Awasthi, Bundy, and Savioli 2003, Pg 432.
"These estimates indicate that ascariasis [roundworm] remains common with >1.2 billion infections globally... Trichuriasis [whipworm] and hookworm amount to 700–800 million infections each." de Silva et al. 2003, Pg 547.
Schistosomiasis estimate is from Mathers, Ezzati, and Lopez 2007, Pg 8, Table 3.
"Clinically, most infected individuals are asymptomatic." Olds 1998, Pg 1696.
"Heavy hookworm burdens have long been recognised as an important cause of iron deficiency anaemia. Intense whipworm infection in children may result in trichuris dysentery syndrome, the classic signs of which include growth retardation and anaemia." Awasthi, Bundy, and Savioli 2003, Pg 432.
Jamison et al. 2006, Pg 467.
"Crompton (1999) estimated that 155,000 deaths annually occur from these infections (case fatality rate of 0.08 percent), whereas Van der Werf and others (2003), using the limited data available from Africa, estimated the schistosomiasis mortality alone at 280,000 per year (case fatality rate of 0.014 percent)." Jamison et al. 2006, Pg 470.
Jamison et al. 2006, Pg 416, Table 21.3.
"Protein-calorie undernutrition and micronutrient deficiencies, particularly zinc and vitamin A, contribute substantially to the malaria burden (Caulfield, Richard,and Black 2004)." Jamison et al. 2006, Pg 414.
"More commonly, the patient presents with a combination of the following symptoms:
* Nausea and vomiting
* Body aches
* General malaise." Centers for Disease Control and Prevention, "Malaria: Disease."
"The manifestations of severe malaria include
* Cerebral malaria, with abnormal behavior, impairment of consciousness, seizures, coma, or other neurologic abnormalities
* Severe anemia due to hemolysis (destruction of the red blood cells)
* Hemoglobinuria (hemoglobin in the urine) due to hemolysis
* Acute respiratory distress syndrome (ARDS), an inflammatory reaction in the lungs that inhibits oxygen exchange, which may occur even after the parasite counts have decreased in response to treatment
* Abnormalities in blood coagulation
* Low blood pressure caused by cardiovascular collapse
* Acute kidney failure
* Hyperparasitemia, where more than 5% of the red blood cells are infected by malaria parasites
* Metabolic acidosis (excessive acidity in the blood and tissue fluids), often in association with hypoglycemia
* Hypoglycemia (low blood glucose). Hypoglycemia may also occur in pregnant women with uncomplicated malaria, or after treatment with quinine." Centers for Disease Control and Prevention, "Malaria: Disease."
Prevalence data in table from World Health Organization, "Disease and Injury Regional Estimates for 2004: Prevalence for World Bank Income Groups. Percentages calculated by dividing prevalence for each region by the regional population.
- 47. "More than 2 billion people, mostly women and young children, are thought to be iron deficient." Jamison et al. 2006, Pg 553.
"STH and schistosomiasis depend for transmission on environments contaminated with egg-carrying feces. Consequently, helminths are intimately associated with poverty, poor sanitation, and lack of clean water." Jamison et al. 2006, Pg 470.
"The overall prevalence of vision loss, which mainly affects the population above age 40, is a function of age. It is estimated that more than 82.2 percent of all blind individuals are 50 or older.... Childhood vision loss represents approximately 4 percent of the total number of visually impaired." Jamison et al. 2006, Pg 954.
"The burden of visual impairment is not distributed uniformly throughout the world; the least developed regions carry the largest share." Jamison et al. 2006, Pg 955.
"Mathers and others (2003) estimate that in 2002, 255 million people worldwide had disabling hearing loss (moderate or worse hearing loss in the better ear). Those 192 million people with adult-onset loss (age 20 years and above) and 63 million people with childhood-onset loss make up almost 4.1 percent of the world’s population and just over 40 percent of all people globally with hearing loss of any severity." Jamison et al. 2006, Pg 957.
"Filarial infection prevalences increase with age, with apparently only small reductions in infection in the oldest adult age classes" Edwin 2000, Pg 46.
"As filariasis is more prevalent in rural areas and in the less affluent members of urban areas" Kumaraswami 2000, Pg 108.
"Number of people living with HIV in 2007
Total 33.2 million [30.6–36.1 million]
Adults 30.8 million [28.2–33.6 million]
Women 15.4 million [13.9–16.6 million]
Children under 15 years 2.5 million [2.2–2.6 million]." UNAIDS 2007, Pg 1.
"VAD [vitamin A deficiency] results from inadequate intakes of vitamin A because of low intakes of animal foods; inadequate intakes of nonanimal sources of carotenoids that are converted to vitamin A; and inadequate intakes of fat, which facilitates the absorption of carotenoids. Dietary sources of preformed vitamin A include liver, milk, and egg yolks. Dark green leafy vegetables such as spinach, as well as yellow and orange noncitrus fruits (mangoes, apricots, papayas) and vegetables (pumpkins, squash, carrots), are common sources of carotenoids (vitamin A precursors), which are generally less bioavailable than preformed vitamin A but tend to be more affordable." Jamison et al. 2006, Pg 553.
"Trachoma is particularly common in young children under five and the adults – mainly women – who care for them.... Repeated exposure to the disease over time eventually causes the inside of the eyelid to turn inward -- a condition called trichiasis -- and the eyelashes to scrape and scar the cornea, leading to the formation of corneal opacities and painful and irreversible blindness. Adult women are three times more likely to develop the blindness associated with trachoma, attributed in part to their close proximity with very young children who are often carriers of the disease." Global Network for Neglected Tropical Diseases 2009, Pg 1.
"The prevalence and intensity of infection and the amount of clinical disease within the endemic community are generally low in young children and increase with age." Simonsen 2009, Pg 1498.
"In sub-Saharan Africa, 26 countries were included in the 2006 poll with random samples of at least 1,000 adults in each country, for a total sample size of 26,506 interviews...Respondents were asked to rank the United Nations Millennium Development Goals (MDGs) in order of importance to them as individuals. The United Nations introduced the MDGs in 2000 when world leaders convened to develop a plan to improve the quality of life in developing countries by taking steps to reduce poverty, hunger, illiteracy, and disease by 2015." Tortora 2009, Pg 1.
Twelve goals were ranked. The goals were: 1. Reducing poverty, 2. Reducing hunger, 3. Achieving primary education for all, 4. Achieving gender equality and empowering women, 5. Reducing the death rate among children under five, 6. Reducing the number of women dying during childbirth, 7. Reducing the spread of HIV/AIDS, 8. Reducing the spread of malaria and TB, 9. Improving access to safe drinking water, 10. Improving access to sanitation facilities, 11. Providing access to new technology, and 12. Providing more jobs for youth. From Tortora 2009, Pg 7.
"The Gallup World Poll findings reveal sub-Saharan Africans’ top priorities: poverty and hunger reduction." Tortora 2009, Pg 21.
“After all, countries with high rates of HIV prevalence do not systematically report poorer health satisfaction, a finding that is in line with earlier reports that self-reported health measures are often better in places where people are sicker, and presumably more used to being sick (Sen, 2002; Murray and Chen, 1992).” Deaton 2008, Pg 13.
Tortora 2009, Pg 8, Table 1.
"A demographic analysis of these rankings shows few differences in goal priorities by age, gender, and education level. Furthermore, when looking at the urban/rural split or employment status, the analysis also shows few variances." Tortora 2009, Pg 21.
Tortora 2009, Pgs 18-20, Tables 9-12.


from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Of or relating to the Moors or their culture.
- adj. Of, relating to, or being a style of Spanish architecture of the 8th to the 16th century, characterized by the horseshoe arch and ornate decoration.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. of or pertaining to the Moors or their culture
- adj. Of or pertaining to a style of Spanish architecture from the time of the Moors, characterized by the horseshoe arch and ornate, geometric decoration
from the GNU version of the Collaborative International Dictionary of English
- adj. Having the characteristics of a moor or heath.
- adj. Of or pertaining to Morocco or the Moors; in the style of the Moors.
from The Century Dictionary and Cyclopedia
- Marshy; resembling a. moor.
- Belonging to a moor; growing on a moor: as, moorish reeds.
- Having the qualities of a moor; characterless; barren.
- Of or pertaining to the Moors.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. relating to or characteristic of the Moors
- n. a style of architecture common in Spain from the 13th to 16th centuries; characterized by horseshoe-shaped arches
In fact, in Spain they were called Moorish skewers.
There was a Jewish scholar, Isaac ben Joshua, in Moorish Spain who said that the Book drove everyone who saw it crazy.
Inquisitorial system has deprived this kingdom by the total expulsion of the Jews, the conquered Moors and the baptized Moorish, we add about
It's probably fair to say that morris dancing, most likely a corruption of the word Moorish, has something of an image problem.
As far as the Liberty City group was concerned this was nonsense; the group of men, who were arrested for plotting to blow up the Sears Tower in Chicago, smoked a great deal of marijuana and subscribed to the obscure beliefs of an outfit called the Moorish Science Temple; so nascent were their terrorist plans that they never even bothered to travel to Chicago.
And perhaps neither of us saw the real truth of the problem underlying what we are pleased to call the Moorish Question.
Others wearing a kind of short brown vest, striped with blue and red, conveying the idea of Moorish garb.
EAST COWES CASTLE, which enjoys a truly enviable site (for it combines an uncommon degree of shelter with the most extensive and _animated_ prospect), is built in the bold style usually termed the Moorish, and has three handsome fronts of varied elevations, with a tasteful diversity of towers, mantled more or less by the most luxuriant ivy, and
Brannon's Picture of The Isle of Wight The Expeditious Traveller's Index to Its Prominent Beauties & Objects of Interest. Compiled Especially with Reference to Those Numerous Visitors Who Can Spare but Two or Three Days to Make the Tour of the Island.
There is a strange immobility about Andalusian beggars which recalls their Moorish ancestry.
It seems now established that it may not be called Moorish, as it has nothing in common with the Moorish architecture as exemplified in the Orient and Southern Spain, although it bears traces of the influence exercised by Moorish art over the Renaissance in Spain.


Machine Learning in Education
What insights about student learning can be revealed from data, and how can those insights be used to improve the efficacy of educational technology? This course will cover computational approaches to the task of modeling learning and improving outcomes in Intelligent Tutoring Systems (ITS) and Massive Open Online Courses (MOOCs). We will cover theories and methodologies underpinning current approaches to knowledge discovery and data mining in education and survey the latest developments in the broad field of human learning research.
This course will be project based, where teams will be introduced to online learning platforms and their datasets with the objective of pairing data analysis with theory or implementation. Literature review will serve to add context and grounding to projects.
Suggested background includes one programming course and familiarity with one statistical/computational software package.
The study of learning in online environments is an interdisciplinary pursuit, and therefore all majors are welcomed and encouraged to bring complimentary backgrounds.
NOTE: This course is cross-listed as Education C260F. Machine Learning in Education.
(Previously offered as Info 290 & Educ 290A.)


Breakfast Myths Busted: Skipping the first meal DOES NOT affect our health
You must have heard that skipping your breakfast is not good for your health. As your stomach is empty for a long time before breakfast, so the first meal of the day should be the heaviest. At that moment, the sugar level in your body is also extremely low for being in the fasted state. So, breakfast should always be heaviest of all the three prime meals of a day. Researches also say that having a proper breakfast helps you to lose your weight. It provides you with all the important nutrients which are lacking due to the fasting period.
On the other hand, it is said that skipping breakfast is highly unhealthy because we are keeping our stomach empty for a longer period. And this also makes us eat more during lunch which directly contributes in weight gain. But are they really genuine? Is it really too bad to skip breakfast? Well, some advanced studies have started to question about this pattern. And they have also researched about breakfast and the effects of skipping it. Let’s find out.
Effects of Skipping Breakfast: Is it bad for our health?
Breakfast eaters are healthier
It is often said that people who eat timely breakfast are healthier than others. But a recent study said that it is an observational study as it has been observed some people who eat breakfast regularly on a particular time. But it’s not rational to say that it's because of the breakfast. They must be living a healthy lifestyle. For example, they tend to workout regularly, don’t smoke or drink that much and eat healthy, etc. And one should also add nutritious and fibre rich foods in the breakfast for staying healthy. These all together contribute in a person’s health, not the breakfast alone. So, the bottom line is you need to maintain an overall healthy lifestyle. And it doesn’t have anything to do with only the breakfast.
Does breakfast improve metabolism?
People believe that having healthy breakfast can boost their metabolism, which is a myth. There is no connection between breakfast and metabolism as metabolism depends a lot on the total amount of food that we consume throughout the day. Studies have shown that people who eat and skip breakfast burn the equal amount of calories.
Does skipping breakfast cause weight gain?
There is no evidence of it. It’s natural to eat more during lunch if you have skipped your breakfast as it makes you more hungry and so you try to adjust it in your lunch. But the study shows, eating more at lunch cannot compensate for your breakfast. On the other hand, skipping breakfast can actually reduce your calorie intake on a day as you are removing an entire meal from your diet plan every day.
This has been experimented on overweight and obese people. Some of them have taken breakfast and some skipped it. There was no difference in their weight after the study was over. So, we really cannot rely on this point that having breakfast aids in weight loss.
Does skipping breakfast have any health benefits?
We are not allowed to eat breakfast in many intermittent fasting diet methods. This type of diet has shown to be effectively reducing calorie intake, aiding in weight loss and increasing body metabolism. But this fasting diet doesn’t suit everyone. Some people get benefited with it, while others may experience headache, sugar fall, etc. So, talk to your dietician before starting the intermittent diet.
Breakfast can be optional
There are lot of myths associated with breakfast. But skipping it cannot make you gain weight overnight. And it is also not connected to increased metabolism rate. Breakfast is optional. But if you feel hungry in the morning and like to have something, then you can definitely eat some protein-rich foods like boiled eggs. The only thing is staying on an empty stomach for a long time may form gas which can cause acid. So, be careful about that.


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The brain's lower-level structures consist of the brain stem and spinal cord, along with the cerebellum.
With the exception of the spinal cord, hese structures are largely located within the hindbrain, diencephalon (or interbrain), and midbrain.
The brain evolved from back to front, such that the structures at the base of the brain, including the hindbrain and midbrain, are more geared towards basic body processes than those in the front.
The hindbrain, which includes the medulla oblongata, the pons, and the cerebellum, is responsible some of the oldest and most primitive body functions.
Each of these structures is described below.
The medulla oblongata sits at the transition zone between the brain and the spinal cord.
It is the first region that formally belongs to the brain and is the control center for respiratory, cardiovascular and digestive functions.
The pons connects the medulla oblongata with the midbrain region.
The pons houses the control centers for respiration and inhibitory functions.
Attached to the dorsal aspect of the pons is the cerebellum.
The cerebellum is a separate region of the brain located behind the medulla oblongata and pons.
It is attached to the rest of the brain by three stalks (called pedunculi), and coordinates skeletal muscles to produce smooth, graceful motions.
The cerebellum receives information from our eyes, ears, muscles, and joints about the body's current positioning (referred to as proprioception).
It also receives output from the cerebral cortex about where these body parts should be.
After processing this information, the cerebellum sends motor impulses from the brain stem to the skeletal muscles so that they can move.
The main function of the cerebellum is coordination; however it is also responsible for balance and posture and it assists us when we are learning a new motor skill, such as playing a sport or musical instrument.
Recent research shows that apart from motor functions the cerebellum also has some role in emotional sensitivity.
The midbrain is located between the hind- and forebrain.
It displays the same basic functional composition as found in the spinal cord and the hindbrain.
Ventral areas control motor function and accommodate tracts that convey motor information from the cerebral cortex.
Dorsal regions of the midbrain are implicated in sensory information circuits.
The Diencephalon ("interbrain")
The diencephalon is the region of the embryonic vertebrate neural tube which gives rise to posterior forebrain structures.
In adults, the diencephalon appears at the upper end of the brain stem, situated between the cerebrum and the brain stem.
It is made up of four distinct components: the thalamus, the subthalamus, the hypothalamus and the epithalamus.
The thalamus is part of the limbic system and consists of two lobes of grey matter along the bottom of the cerebral cortex.
Lesions or stimulation to the thalamus are associated with changes in emotional reactivity.
However, the importance of this structure on the regulation of emotional behavior is not due to the thalamus itself, but to the connections between the thalamus with other limbic system structures.
The hypothalamus is a small part of the brain located just below the thalamus.
Lesions of the hypothalamus interfere with several so-called motivated behaviors like sexuality, combativeness, and hunger.
The hypothalamus also plays a role in emotion.
Specifically, parts of the thalamus seem to be involved with pleasure and rage, while the central part is linked to aversion, displeasure, and a tendency towards uncontrollable and loud laughing.
When external stimuli are presented (for example, a dangerous stimuli), the hypothalamus sends signals to other limbic areas to trigger feeling states in response to the stimuli (in this case, fear).
The Spinal Cord
The spinal cord is a tail-like structure that is embedded in the vertebral canal of the spine.
The adult spinal cord has a length of 40 cm and weighs approximately 30g.
The spinal cord is attached to the underside of the medulla oblongata, and is organized to serve four distinct tasks:
to convey mainly sensory information to the brain,
to carry centrally information generated in the brain to control peripheral targets like skeletal muscles,
to control nearby organs via the autonomic nervous system, and
to enable sensorimotor functions to to control posture and other fundamental movements.


Ever since superheroes became the best-selling movie characters, origin stories are all the rage. You didn’t think, though, that they are the only ones that have them, right? Every tradition, every habit we have has a story behind it, a reason why we do things the way we do them. Why would, say, foods be an exception?
If you ever wondered why some foods look the way they do, here is a bit of clarity about them.
The bagel originated in the Jewish communities in Poland around the 1600s. Over the years, it has become a staple for the Slavic nations, with its name transforming from the Yiddish beygal (meaning ring or bracelet) to the term we know today.
But why does it have a hole in the middle? Actually, there is a fun origin story about the mystery of the bagel hole, and it involves a wise rabbi and the tzar.
Legend has it, the people of Chelm – a city in Poland – were required to surrender a tenth of all the bread they baked. Not just any bread, though – the middle tenth of each loaf because it was the softest part with the least crust. So, the wise men of Chelm got together and found a solution: they baked small loaves with holes in the middle, and the holes represented exactly one-tenth of each loaf. And when the tzar’s soldiers came to collect the royal tithe, they had no choice but to leave with… nothing.
The sandwich is perhaps the most self-evident food: take two pieces of bread, put stuff in between, hold it in your hand and bite. In the 1700s, in turn, it apparently wasn’t. At least not until Lord John Montagu came along. The lord, like many others at the time, was a prolific gambler. He was often so absorbed in his games that he couldn’t be called away from the tables, not even to eat. Instead, he grabbed a piece of roast beef and ate it with his bare hands. Doing so, he redefined the term “playing dirty”, messing up the cards in the process.
To avoid this, he used two pieces of bread to hold the meat. The idea was great, and others soon followed suit. And, since Lord John Montagu was the Earl of Sandwich, the name given to this new way to eat was obvious.
Unlike the other two foods above, coffee wasn’t invented – it was discovered. The credit for this amazing discovery that gives energy to an entire world goes to… a goat. An Ethiopian one.
Legend has it, the first human to discover coffee was a 15th-century Ethiopian goat herder called Kaldi who saw his goats go berserk whenever they have eaten the fruits of a shrub. Moreover, they didn’t want to sleep at night.
The berries were first brewed into a drink by the abbot of a local monastery to keep him alert through the night prayer. From there, the berries were taken to Arabia, from there, it spread to Egypt, Syria, and Turkey, and, by the 17th century, to Europe. And from there, it conquered the entire world, becoming the second most consumed beverage of the globe.


- The keyword mnemonic is undoubtedly an effective means of learning the words of a foreign language.
- How well you remember depends on how well you learned them, not on whether you have learned the words using a keyword mnemonic or rote repetition or some other method.
- Even using a keyword mnemonic, you still need to rehearse the information to be learned.
- The keyword mnemonic is not always the best method of learning particular words.
- Skilled learners may be best to use the keyword mnemonic selectively, for particularly difficult words.
- The keyword mnemonic requires individual instruction and practice, to use effectively.
- Using a verbal (sentence) link is at least as effective as an image, and is easier for many people.
- Whether using a sentence or an image, the critical factor is that the keyword interact with the definition or own-language word.
In the mid-seventies, Raugh and Atkinson had remarkable results using the keyword method to teach Russian vocabulary to college students. While later studies have not tended to find such dramatic results, nevertheless, a large number of studies have demonstrated an advantage in using the keyword mnemonic to learn vocabulary.
Some researchers have become huge fans of the strategy. Others have suggested a number of limitations. Let’s look at these.
Remembering for the long term
The keyword method is undeniably an effective method for accelerating learning of suitable material. Nor is there any doubt that it improves immediate recall. Which can be useful in itself. However, what people want is long-term recall, and it is there that the advantages of the keyword method are most contentious1.
While many studies have found good remembering a week or two after learning using the keyword mnemonic, others have found that remembering is no better one or two weeks later whether people have used the keyword mnemonic or another strategy. Some have found it worse.
It has been suggested that, although the keyword may be a good retrieval cue initially, over time earlier associations may regain their strength and make it harder to retrieve the keyword image. This seems very reasonable to me — any keyword is, by its nature, an easily retrieved, familiar word; therefore, it will already have a host of associations. When you’re tested immediately after learning the keyword, this new link will of course be fresh in your mind, and easily retrieved. But as time goes on, and the advantage of recency is lost, what is there to make the new link stronger than the other, existing, links? Absolutely nothing — unless you strengthen it. How? By repetition.
Note that it is not the keyword itself that fails to be remembered. It is the image. The weakness then, is in the link between keyword and image. (For example, the Tagalog word araw, meaning sun, is given the keyword arrow; when tested, araw easily recalls the keyword arrow, but the image connecting arrow with sun is gone). This is the link you must strengthen.
The question of the relative forgetting curves of the keyword mnemonic and other learning strategies is chiefly a matter of theoretical interest — I don’t think any researcher would deny that repetition is always necessary. But the “magic” of the keyword mnemonic, as espoused by some mnemonic enthusiasts, downplays this necessity. For practical purposes, it is merely sufficient to remember that, for long-term learning, you must strengthen this link between keyword and image (or sentence) through repeated retrieval (but probably not nearly as often as the repetition needed to “fix” meaningless information that has no such mnemonic aid).
One final point should be made. If the material to be learned is mastered to the same standard, the durability of the memory — how long it is remembered for — will, it appears, be the same, regardless of the method used to learn it2.
Are some keyword mnemonics easier to remember than others?
A number of factors may affect the strength of a keyword mnemonic. One that’s often suggested is whether or not the mnemonic is supplied to the student, or thought up by them. Intuitively, we feel that a mnemonic you’ve thought up yourself will be stronger than one that is given to you.
One study that compared the effectiveness of keywords provided versus keywords that are self-generated, found that participants who were required to make up their own keywords performed much worse than those who were given keywords3. This doesn’t answer the question of the relative durability, but it does point to how much more difficult the task of generating keywords is. This has been confirmed in other studies.
The quality of the keyword mnemonic may affect its durability. Mnemonics that emphasize distinctiveness, that increase the vividness and concreteness of the word to be learned, are remembered less well over time than mnemonics that emphasize relational and semantic information (which is why the emphasis in recent times is on making interactive images or sentences, in which the keyword and definition interact in some way). Having bizarre images seems to help remembering immediately after learning (when there is a mix of bizarre and less unusual images), but doesn’t seem to help particularly over the long term.
The advantage of a semantic connection may be seen in the following example, taken from an experimental study3. Students in a free control condition (those told to use their own methods to remember), almost all used a keyword-type technique to learn some items. Unlike those in the keyword group, the keywords chosen by these subjects typically had some semantic connection as well. (The use of somewhat arbitrary keywords is characteristic of the strategy as originally conceived by Atkinson). Thus, for the Spanish word pestana, meaning eyelash, several people used the phrase paste on as a link, reflecting an existing association (pasting on false eyelashes). The keyword supplied to the keyword group, on the other hand, was pest, which has no obvious connection to eyelash. (It is also worth noting that verbal links were more commonly used by control subjects, rather than mental images.)
It has been suggested that keywords that are semantically as well as acoustically related to the word to be learned might prove more durable.
For experimental reasons, the information to be learned is usually presented at a fixed rate, item by item. There is some suggestion that an unpaced situation, where people are simply presented with all the information to be learned and given a set time to study it, allows better learning, most particularly for the repetition strategy. The performance of rote repetition may have been made poorer by constraining it in this way in some experimental studies.
An unpaced study time is of course the more normal situation.
The importance of one-to-one instruction and the need for practice
What is clear from the research is that instruction in the technique is vitally important. Most particularly, the superiority of the keyword mnemonic tends to be found only when the students have been treated individually, not when they have been instructed as a group. At least, this is true for adults and adolescents, but not, interestingly, for children. Children can benefit from group instruction in the technique. Why this is, is not clear. However, I would speculate that it may have something to do with older students having already developed their own strategies and ideas. More individually-oriented instruction might be needed to counteract this depository of knowledge.
It might also be that children are given more direction in the using of the technique. That is, they are given the keywords; the images may be described to them, and even drawn. Clearly this is much simpler than being required to think up your own keywords, create your own links.
It does seem clear that durable keyword images require quite a lot of practice to create. It has been suggested that initially people tend to simply focus on creating distinctive images. It may only be with extensive practice that you become able to reliably create images that effectively integrate the relational qualities of the bits of information.
It has been suggested that the keyword mnemonic works effectively only on concrete words. For the most part, researchers only use concrete words (which are easily imageable). Studies which have compared the two are rare. The weight of the evidence is probably against the view that the mnemonic should be restricted to concrete words, but it may well be more difficult to come up with good, concrete images for abstract words. However, verbal mnemonics (a sentence can link the keyword with the definition) don’t suffer the same drawback.
In experimental studies, the words are usually vetted to make sure they’re not “easy” to learn because of obvious acoustic or graphic similarities with familiar words. The implication of this for real world learning, is that there is no reason to think that such words require a keyword mnemonic.
How important is the image?
Most research has focused on using an image to link the keyword with the definition. One study which compared the using of an image with the use of a sentence (in a study of children’s learning of Spanish words) found no difference (the sentence mnemonic in fact scored higher, but the difference was not significant)4.
Is the keyword mnemonic of greater benefit to less able students?
Several researchers have suggested that the keyword mnemonic might be of greater benefit to less able students, that the keyword mnemonic may be a means by which differences in learning ability might be equalised. One study that failed to find any superiority in the keyword mnemonic among college students, pointed to the high SAT scores of their students. They suggested that those studies which have found a keyword superiority using college students, have used students who were less verbally able5.
What seems likely, is that teaching the keyword mnemonic to more able students has less impact than teaching it to less able students, because the more able students already have a variety of effective strategies that they use. It is worth noting that, just because students are instructed to use a particular strategy, that doesn’t mean that they will. In one experimental study, for example, when subjects were asked about the strategies they used, 17 out of the 40 control subjects (instructed to use their own methods) used the keyword method for at least some items, while every keyword subject used the keyword method for at least seven items (implying they didn’t always). In that study, it was found that, for the control subjects, the probability of recalling keyword-elaborated items was .81 vs .45 for other items; while for the keyword group, the probability of recall for keyword-elaborated items was .80 vs .16 for those items for which they didn’t use a keyword mnemonic6.
Comparing the keyword mnemonic to other strategies
As a general rule, experimental studies into the effectiveness of the keyword mnemonic have compared it to, most often, rote repetition, or, less often, “trying your hardest to remember” (i.e., your own methods). It is not overwhelmingly surprising that the keyword mnemonic should be superior to rote repetition, and the study quoted just above reveals why comparisons with “free” controls might show inconsistent (and uninformative) results.
Studies which have directly compared the keyword method to other elaborative strategies are more helpful.
A number of studies have compared the keyword strategy against the context method of learning vocabulary (much loved by teachers; students experience the word to be learned in several different meaningful contexts). Theory suggests that the context method should encourage multiple connections to the target word, and is thus expected to be a highly effective strategy. However, the studies have found that the keyword method produces better learning than the context method.
It has been suggested that students might benefit more from the context method if they had to work out the meaning of the word themselves, from the context. However, a study which explored this possibility, found that participants using the context method performed significantly worse than those using the keyword mnemonic5. This was true even when subjects were given a test that would be thought to give an advantage to the context method — namely, subjects being required to produce meaningful sentences with the target words.
The same researchers later pursued the possibility that the context method might, nevertheless, prove superior in long-term recall — benefiting from the multiple connections / retrieval paths to the target word. In an experiment where both keyword and context groups learned the words until they had mastered them, recall was no better for the context group than it was for the keyword group, when tested one week later (on the other hand, it was no worse either)2.
Two more recent studies have confirmed the superiority of the keyword mnemonic over the context method7.
Another study looked at the question of whether a combined keyword – repetition strategy (in which subjects were told to use repetition as well as imagery when linking the keyword to the English translation of the word to be learned) was better than the keyword strategy on its own. They failed to find any benefit to using repetition on top of the imagery8.
Given the procedures used, I can see why this might occur. Imagine you’re trying to learn that carta is Spanish for letter. The obvious keyword is cart. Accordingly, you form an image of a cart full of letters. However, having constructed this image, you are now told to repeat the salient words “carta - letter” over and over to yourself. It’s not hard to see that many people might completely lose track of the image while they are doing this. Thus the repetition component of the strategy would not be so much augmenting the imagery link, as replacing it. Repetition of the link you are supposed to be augmenting (a cart full of letters) might be more useful (in fact, I personally would repeat to myself: “carta – letter; a cart full of letters”).
The value of the keyword mnemonic is of course, in forward recall — that is, in the above example, you learned that carta meant letter. When you see the word carta, the keyword mnemonic will help you remember that it means letter. But if you are asked for the Spanish for letter, how helpful will the keyword mnemonic be then?
A study that looked at this question found that the keyword mnemonic was no worse for backward recall than the other strategies they employed8. On the other hand, it was no better, either — and this despite being superior for forward recall (remembering the English when given the Spanish). The failure of the method was not due to any difficulty in recalling the keyword itself. Remember, the English meaning and the keyword are tied together in the mnemonic image, so it is not surprising that remembering the keyword given the English was as high as remembering the English given the keyword. But the problem is, of course, that generating the (unfamiliar) Spanish word from the keyword is much harder than remembering the (familiar) keyword from the Spanish.
Using the keyword mnemonic to remember gender
One other aspect of vocabulary learning for many languages is that of gender. The keyword mnemonic has successfully been used to remember the gender of nouns, by incorporating a gender tag in the image9. This may be as simple as including a man or a woman (or some particular object, when the language also contains a neutral gender), or you could use some other code — for example, if learning German, you could use the image of a deer for the masculine gender.
Why should the keyword mnemonic be an effective strategy?
Let’s think about the basic principles of how memory works.
The strength of memory codes, and thus the ease with which they can be found, is a function largely of repetition. Quite simply, the more often you experience something (a word, an event, a person, whatever), the stronger and more easily recalled your memory for that thing will be.
This is why the most basic memory strategy — the simplest, and the first learned — is rote repetition.
Repetition is how we hold items in working memory, that is, “in mind”. When we are told a phone number and have to remember it long enough to either dial it or write it down, most of us repeat it frantically.
Spaced repetition — repetition at intervals of time — is how we cement most of our memory codes in our long-term memory store. If you make no deliberate attempt to learn a phone number, yet use it often, you will inevitably come to know it (how many repetitions that will take is a matter of individual variability).
But most of us come to realize that repetition is not, on its own, the most effective strategy, and when we deliberately wish to learn something, we generally incorporate other, more elaborative, strategies.
Why do we do that? If memory codes are strengthened by repetition, why isn’t it enough to simply repeat?
Well, it is. Repetition IS enough. But it’s boring. That’s point one.
Point two is that making memory codes more easily found (which is after all the point of the exercise) is not solely achieved by making the memory codes stronger. Also important is making lots of connections. Memory codes are held in a network. We find a particular one by following a trail of linked codes. Clearly, the more trails lead to the code you’re looking for, the more likely you are to find it.
Elaborative strategies — mnemonic strategies, organizational strategies — work on this aspect. They are designed to increase the number of links (connections) a memory code has. Thus, when we note that lamprey is an “eel-like aquatic vertebrate with sucker mouth”, we will probably make links with eels, with fish, with the sea. If we recall that Henry I was said to have died from a surfeit of lampreys, we have made another link. Which in turn might bring in yet another link, that Ngaio Marsh once wrote a mystery entitled “A surfeit of lampreys”. And if you’ve read the book, this will be a good link, being itself rich in links. (As the earlier link would be if you happen to be knowledgeable about Henry I).
On the other hand, in the absence of any knowledge about lampreys, you could have made a mnemonic link with the word “lamp”, and imagined an eel-like fish with lamps in its eyes, or balanced on its head.
So, both types of elaborative strategy have the same goal — to increase the number of connections. But mnemonic links are weaker in the sense that they are arbitrary. Their value comes in those circumstances when either you lack the knowledge to make meaningful connections, or there is in fact no meaningful connection to be made (this is why mnemonics are so popular for vocabulary learning, and for the learning of lists and other ordered information).
Where does that leave us?
- Memory codes are made stronger by repetition
- Repetition is enough on it’s own to make a strong memory code
- Achieving enough repetitions, however, is a lengthy and often boring process
- Memory codes are also made easier to find by increasing the number of links they have to other memory codes
- Elaborative strategies work on this principle of making connections with existing codes
- Some elaborative strategies make meaningful connections between memory codes — these are stronger
- Mnemonic strategies make connections that are not meaningful
- Mnemonic strategies are most useful in situations where there are no meaningful connections to be made, or you lack the knowledge to make meaningful connections
Mnemonic strategies have therefore had particular success in the learning of other languages. However, if you can make a meaningful connection, that will be more effective. For example, in Spanish the word surgir means to appear, spout, arise. If you connect this to the word surge, from the Latin surgere, to rise, then you have a meaningful connection, and you won’t, it is clear, have much trouble when you come across the word. However, if your English vocabulary does not include the word surge, you might make instead a mnemonic connection, such as surgir sounds like sugar, so you make a mental image involving spouting sugar. Now, imagine each of these situations. Imagine you don’t come across the word again for a month. When you do, which of these connections is more likely to bring forth the correct meaning?
But of course, it is not always possible to make meaningful connections.
The thing to remember however, is that you haven’t overcome the need for repetition. These strategies are adjuncts. The basic principle must always be remembered: Memory codes are made stronger by repetition. Links are made stronger by repetition. If you don’t practice the mnemonic, it won’t be remembered. The same is true for any connection, but meaningful connections are inherently stronger, so they don’t need as many repetitions.
I would also note that the experimental research invariably involves very limited numbers of words to be learned. While this is entirely understandable, it does raise the question of the extent to which these findings are applicable to real world learning situations. If you are learning a new language, you are going to have to learn at least 2000 new words. Does the keyword mnemonic hold up in those circumstances? The keyword mnemonic has been used in real world situations (intensive language courses), but these are not experimental situations, and we must be wary of the conclusions we draw from them. The keyword strategy does take time and effort to implement, and may well have disadvantages if used to excess. Some words lend themselves to other techniques. At least for more experienced students (who will have a number of effective strategies, and are capable of applying them appropriately) the keyword strategy is probably best used selectively, perhaps for particularly difficult items.
1. Wang, A.Y. & Thomas, M.H. 1992. The Effect of Imagery-Based Mnemonics on the Long-Term Retention of Chinese Characters.
Wang, A.Y. et al. 1989. Do Mnemonic Devices Lessen Forgetting? Paper presented at the Annual Meeting of the American Psychological Association (97th, New Orleans, LA, August 11-15, 1989).
Wang, A.Y. et al. 1992. Keyword Mnemonic and Retention of Second-Language Vocabulary Words.
Wang, A.Y. & Thomas, M.H. 1995. Effect of keywords on long-term retention: help or hindrance? Journal of Educational Psychology, 87, 468-75.
Gruneberg, M.M.1998. A commentary on criticism of the keyword method of learning foreign languages. Applied Cognitive Psychology , 12, 529-532.
Wang, A.Y. & Thomas, M.H. 1999. In defence of keyword experiments: a reply to Gruneberg's commentary
2. McDaniel, M.A., Pressley, M. & Dunay, P.K. 1987. Long-term retention of vocabulary after keyword and context learning. Journal of Educational Psychology, 79, 87-9.
3. Hall, J.W., Wilson, K.P. & Patterson, R.J. 1981. Mnemotechnics: Some limitations of the mnemonic keyword method for the study of foreign language vocabulary. Journal of Educational Psychology, 73, 345-57.
4. Pressley, M., Levin, J.R. & Miller, G.E. 1981. The keyword method and children’s learning of foreign vocabulary with abstract meanings. Canadian Journal of Psychology, 34, 283-87.
5. McDaniel, M.A. & Pressley, M. 1984. Putting the keyword method in context. Journal of Educational Psychology, 76, 598-609.
6. Pressley, M., Levin, J.R., Digdon, N., Bryant, S.L. & Ray, K. 1983. Does method of item presentation affect keyword method effectiveness? Journal of Educational Psychology, 75, 686-91.
7. Jones, M.S., Levin, M.E., Levin, J.R. & Beitzel, B.D. 2000. Can vocabulary-learning strategies and pair-learning formats be profitably combined? Journal of Educational Psychology, 92, 256-62.
Shing, Y.S. & Heyworth, R.M. 1992. Teaching English Vocabulary to Cantonese-speaking Students with the Keyword Method. Education Journal, 20, 113-129.
8. Pressley, M., Levin, J.R., Hall, J.W., Miller, G.E. & Berry, J.K. 1980. The keyword method and foreign word acquisition. Journal of Experimental Psychology: Human Learning and Memory, 6, 163-73.
9. Desrochers, A., Gelinas & Wieland, L.D. 1989. An application of the mnemonic keyword method to the acquisition of German nouns and their grammatical gender. Journal of Educational Psychology, 81, 25-32.


Year 6 Science Investigation
What enable us to see? How does light reflect? Why can you see yourself in a mirror? These are just some of the scientific questions that Year 6 are exploring in their study of the topic of 'Light' this half term.
This week 6LY built periscopes to explore how the reflection of light off a mirror can be used in practical applications in every day life. They discovered that for their periscopes to work effectively the angle of the mirror was very important, 45 degrees was the crucial measurement. Once they had constructed their periscope accurately the pupils were able to have great fun spying over desks and peeping round corners, as you can see from the photos in our latest gallery.
Thank you to everyone who sent in empty juice cartons to make this investigation possible. 6KW and 6CW will be building their periscopes next week - we still need approximataly 20 more juice cartons for them to go ahead so please do keep on sending in the cartons until Wednesday of next week. Thank you so much!