---
language: 
- hr
- bs
- sr
- cnr
- hbs

license: apache-2.0
---

# BERTić* [bert-ich] /bɜrtitʃ/ - A transformer language model for Bosnian, Croatian, Montenegrin and Serbian

* The name should resemble the facts (1) that the model was trained in Zagreb, Croatia, where diminutives ending in -ić (as in fotić, smajlić, hengić etc.) are very popular, and (2) that most surnames in the countries where these languages are spoken end in -ić (with diminutive etymology as well).

This Electra model was trained on more than 6 billion tokens of Bosnian, Croatian, Montenegrin and Serbian text.

Comparing this model to [multilingual BERT](https://huggingface.co/bert-base-multilingual-cased) and [CroSloEngual BERT](https://huggingface.co/EMBEDDIA/crosloengual-bert) on the tasks of part-of-speech tagging, named entity recognition, geolocation prediction and choice of plausible alternatives shows this model to be superior to the other two.

## Part-of-speech tagging

Evaluation metric is (seqeval) microF1. Reported are means of five runs. Best results are presented in bold. Statistical significance is calculated between two best-performing systems via a two-tailed t-test (&ast; p<=0.05, &ast;&ast; p<=0.01, &ast;&ast;&ast; p<=0.001, &ast;&ast;&ast;&ast;&ast; p<=0.0001).

Dataset  | Language | Variety | CLASSLA | mBERT | cseBERT | BERTić
---|---|---|---|---|---|---
hr500k | Croatian | standard | 93.87 | 94.60 | 95.74 | **95.81&ast;&ast;&ast;**
reldi-hr | Croatian | internet non-standard | - | 88.87 | 91.63 | **92.28&ast;&ast;&ast;**
SETimes.SR | Serbian | standard | 95.00 | 95.50 | **96.41** | 96.31
reldi-sr | Serbian | internet non-standard | - | 91.26 |  93.54 | **93.90&ast;&ast;&ast;**

## Named entity recognition

Evaluation metric is (seqeval) microF1. Reported are means of five runs. Best results are presented in bold. Statistical significance is calculated between two best-performing systems via a two-tailed t-test (&ast; p<=0.05, &ast;&ast; p<=0.01, &ast;&ast;&ast; p<=0.001, &ast;&ast;&ast;&ast;&ast; p<=0.0001).

Dataset  | Language | Variety | CLASSLA | mBERT | cseBERT | BERTić
---|---|---|---|---|---|---
hr500k | Croatian | standard | 80.13 | 85.67 | 88.98 | **89.21&ast;&ast;&ast;&ast;**
reldi-hr | Croatian | internet non-standard | - | 76.06 | 81.38 | **83.05&ast;&ast;&ast;&ast;**
SETimes.SR | Serbian | standard | 84.64 | **92.41** | 92.28 | 92.02
reldi-sr | Serbian | internet non-standard | - | 81.29 | 82.76 | **87.92&ast;&ast;&ast;&ast;**


## Geolocation prediction

Evaluation metrics are median and mean of distance between gold and predicted geolocations (lower is better). No statistical significance is computed due to large test set (39,723 instances). Centroid baseline predicts each text to be created in the centroid of the training dataset.

System | Median | Mean
---|---|---
centroid | 107.10 | 145.72 
mBERT | 42.25 | 82.05 
cseBERT | 40.76 | 81.88
BERTić | **37.96** | **79.30**

## Choice Of Plausible Alternatives (translation to Croatian)

Evaluation metric is accuracy. Best results are presented in bold. Statistical significance is calculated between two best-performing systems via a two-tailed t-test (&ast; p<=0.05, &ast;&ast; p<=0.01, &ast;&ast;&ast; p<=0.001, &ast;&ast;&ast;&ast;&ast; p<=0.0001).

System | Accuracy
---|---
random | 50.00
mBERT | 54.12
cseBERT | 61.80
BERTić | **65.76&ast;&ast;**