Nikola Ivačič


2024

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Comparing News Framing of Migration Crises using Zero-Shot Classification
Nikola Ivačič | Matthew Purver | Fabienne Lind | Senja Pollak | Hajo Boomgaarden | Veronika Bajt
Proceedings of the First Workshop on Reference, Framing, and Perspective @ LREC-COLING 2024

We present an experiment on classifying news frames in a language unseen by the learner, using zero-shot cross-lingual transfer learning. We used two pre-trained multilingual Transformer Encoder neural network models and tested with four specific news frames, investigating two approaches to the resulting multi-label task: Binary Relevance (treating each frame independently) and Label Power-set (predicting each possible combination of frames). We train our classifiers on an available annotated multilingual migration news dataset and test on an unseen Slovene language migration news corpus, first evaluating performance and then using the classifiers to analyse how media framed the news during the periods of Syria and Ukraine conflict-related migrations.

2023

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Analysis of Transfer Learning for Named Entity Recognition in South-Slavic Languages
Nikola Ivačič | Thi Hong Hanh Tran | Boshko Koloski | Senja Pollak | Matthew Purver
Proceedings of the 9th Workshop on Slavic Natural Language Processing 2023 (SlavicNLP 2023)

This paper analyzes a Named Entity Recognition task for South-Slavic languages using the pre-trained multilingual neural network models. We investigate whether the performance of the models for a target language can be improved by using data from closely related languages. We have shown that the model performance is not influenced substantially when trained with other than a target language. While for Slovene, the monolingual setting generally performs better, for Croatian and Serbian the results are slightly better in selected cross-lingual settings, but the improvements are not large. The most significant performance improvement is shown for the Serbian language, which has the smallest corpora. Therefore, fine-tuning with other closely related languages may benefit only the “low resource” languages.