Abstract
This paper investigates how Transformer language models (LMs) fine-tuned for acceptability classification capture linguistic features. Our approach is based on best practices of topological data analysis (TDA) in NLP: we construct directed attention graphs from attention matrices, derive topological features from them and feed them to linear classifiers. We introduce two novel features, chordality and the matching number, and show that TDA-based classifiers outperform fine-tuning baselines. We experiment with two datasets, CoLA and RuCoLA, in English and Russian, which are typologically different languages. On top of that, we propose several black-box introspection techniques aimed at detecting changes in the attention mode of the LM’s during fine-tuning, defining the LM’s prediction confidences, and associating individual heads with fine-grained grammar phenomena. Our results contribute to understanding the behaviour of monolingual LMs in the acceptability classification task, provide insights into the functional roles of attention heads, and highlight the advantages of TDA-based approaches for analyzing LMs.We release the code and the experimental results for further uptake.- Anthology ID:
- 2023.bsnlp-1.15
- Volume:
- Proceedings of the 9th Workshop on Slavic Natural Language Processing 2023 (SlavicNLP 2023)
- Month:
- May
- Year:
- 2023
- Address:
- Dubrovnik, Croatia
- Editors:
- Jakub Piskorski, Michał Marcińczuk, Preslav Nakov, Maciej Ogrodniczuk, Senja Pollak, Pavel Přibáň, Piotr Rybak, Josef Steinberger, Roman Yangarber
- Venue:
- BSNLP
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 123–137
- Language:
- URL:
- https://aclanthology.org/2023.bsnlp-1.15
- DOI:
- 10.18653/v1/2023.bsnlp-1.15
- Cite (ACL):
- Irina Proskurina, Ekaterina Artemova, and Irina Piontkovskaya. 2023. Can BERT eat RuCoLA? Topological Data Analysis to Explain. In Proceedings of the 9th Workshop on Slavic Natural Language Processing 2023 (SlavicNLP 2023), pages 123–137, Dubrovnik, Croatia. Association for Computational Linguistics.
- Cite (Informal):
- Can BERT eat RuCoLA? Topological Data Analysis to Explain (Proskurina et al., BSNLP 2023)
- PDF:
- https://preview.aclanthology.org/emnlp-22-attachments/2023.bsnlp-1.15.pdf