Nevena Grigorova
2025
Automatic Detection of the Bulgarian Evidential Renarrative
Irina Temnikova | Ruslana Margova | Stefan Minkov | Tsvetelina Stefanova | Nevena Grigorova | Silvia Gargova | Venelin Kovatchev
Journal Computational Linguistics in Bulgaria
Irina Temnikova | Ruslana Margova | Stefan Minkov | Tsvetelina Stefanova | Nevena Grigorova | Silvia Gargova | Venelin Kovatchev
Journal Computational Linguistics in Bulgaria
Manual and automatic verification of the trustworthiness of information is an important task. Knowing whether the author of a statement was an eyewitness to the reported event(s) is a useful clue. In linguistics, such information is expressed through “evidentiality”. Evidentials are especially important in Bulgarian, as Bulgarian journalists often use a specific type of evidential (“renarrative”) to report events that they did not directly observe, nor verify. Unfortunately, there are no automatic tools to detect Bulgarian renarrative. This article presents the first two automatic solutions for this task. Specifically - a fine-tuned BERT classifier (renarrative BERT detector, BGRenBERT), achieving 0.98 Accuracy on the test split, and a renarrative rulebased detector (BGRenRules), created with regular expressions, matching a parser’s output. Both solutions detect Bulgarian texts containing the most frequently encountered forms of renarrative. Additionally, we compare the results of the two detectors with the manual annotation of subsets of two Bulgarian fake text datasets. BGRenRules obtains substantially higher results than BGRenBERT. The error analysis shows that the errors from BGRenRules most frequently correspond to cases in which humans also have doubts. The training dataset (BgRenData), the annotated dataset subsets, and the two detectors are made publicly accessible on Zenodo, GitHub, and HuggingFace. We expect that these new resources will be of invaluable assistance to 1) Bulgarian-language researchers, 2) researchers of other languages with similar phenomena, especially those working on verifying information.
A Comparative Study of Hyperbole Detection Methods: From Rule-Based Approaches through Deep Learning Models to Large Language Models
Silvia Gargova | Nevena Grigorova | Ruslan Mitkov
Proceedings of the First Workshop on Comparative Performance Evaluation: From Rules to Language Models
Silvia Gargova | Nevena Grigorova | Ruslan Mitkov
Proceedings of the First Workshop on Comparative Performance Evaluation: From Rules to Language Models
We address hyperbole detection as a binary classification task, comparing rule-based methods, fine-tuned transformers (BERT, RoBERTa), and large language models (LLMs) in zero-shot and few-shot prompting (Gemini, LLaMA). Fine-tuned transformers achieved the best overall performance, with RoBERTa attaining an F1-score of 0.82. Rule-based methods performed lower (F1 = 0.58) but remain effective in constrained linguistic contexts. LLMs showed mixed results: zero-shot performance was variable, while few-shot prompting notably improved outcomes, reaching F1-scores up to 0.79 without task-specific training data. We discuss the trade-offs between interpretability, computational cost, and data requirements across methods. Our results highlight the promise of LLMs in low-resource scenarios and suggest future work on hybrid models and broader figurative language tasks.
2024
SM-FEEL-BG - the First Bulgarian Datasets and Classifiers for Detecting Feelings, Emotions, and Sentiments of Bulgarian Social Media Text
Irina Temnikova | Iva Marinova | Silvia Gargova | Ruslana Margova | Alexander Komarov | Tsvetelina Stefanova | Veneta Kireva | Dimana Vyatrova | Nevena Grigorova | Yordan Mandevski | Stefan Minkov
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)
Irina Temnikova | Iva Marinova | Silvia Gargova | Ruslana Margova | Alexander Komarov | Tsvetelina Stefanova | Veneta Kireva | Dimana Vyatrova | Nevena Grigorova | Yordan Mandevski | Stefan Minkov
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)
This article introduces SM-FEEL-BG – the first Bulgarian-language package, containing 6 datasets with Social Media (SM) texts with emotion, feeling, and sentiment labels and 4 classifiers trained on them. All but one dataset from these are freely accessible for research purposes. The largest dataset contains 6000 Twitter, Telegram, and Facebook texts, manually annotated with 21 fine-grained emotion/feeling categories. The fine-grained labels are automatically merged into three coarse-grained sentiment categories, producing a dataset with two parallel sets of labels. Several classification experiments are run on different subsets of the fine-grained categories and their respective sentiment labels with a Bulgarian fine-tuned BERT. The highest Acc. reached was 0.61 for 16 emotions and 0.70 for 11 emotions (incl. 310 ChatGPT 4-generated texts). The sentiments Acc. of the 11 emotions dataset was also the highest (0.79). As Facebook posts cannot be shared, we ran experiments on the Twitter and Telegram subset of the 11 emotions dataset, obtaining 0.73 Acc. for emotions and 0.80 for sentiments. The article describes the annotation procedures, guidelines, experiments, and results. We believe that this package will be of significant benefit to researchers working on emotion detection and sentiment analysis in Bulgarian.