Exploring Linguistic Properties of Monolingual BERTs with Typological Classification among Languages

Elena Sofia Ruzzetti, Federico Ranaldi, Felicia Logozzo, Michele Mastromattei, Leonardo Ranaldi, Fabio Massimo Zanzotto


Abstract
The impressive achievements of transformers force NLP researchers to delve into how these models represent the underlying structure of natural language. In this paper, we propose a novel standpoint to investigate the above issue: using typological similarities among languages to observe how their respective monolingual models encode structural information. We aim to layer-wise compare transformers for typologically similar languages to observe whether these similarities emerge for particular layers. For this investigation, we propose to use Centered Kernel Alignment to measure similarity among weight matrices. We found that syntactic typological similarity is consistent with the similarity between the weights in the middle layers, which are the pretrained BERT layers to which syntax encoding is generally attributed. Moreover, we observe that a domain adaptation on semantically equivalent texts enhances this similarity among weight matrices.
Anthology ID:
2023.findings-emnlp.963
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2023
Month:
December
Year:
2023
Address:
Singapore
Editors:
Houda Bouamor, Juan Pino, Kalika Bali
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
14447–14461
Language:
URL:
https://aclanthology.org/2023.findings-emnlp.963
DOI:
10.18653/v1/2023.findings-emnlp.963
Bibkey:
Cite (ACL):
Elena Sofia Ruzzetti, Federico Ranaldi, Felicia Logozzo, Michele Mastromattei, Leonardo Ranaldi, and Fabio Massimo Zanzotto. 2023. Exploring Linguistic Properties of Monolingual BERTs with Typological Classification among Languages. In Findings of the Association for Computational Linguistics: EMNLP 2023, pages 14447–14461, Singapore. Association for Computational Linguistics.
Cite (Informal):
Exploring Linguistic Properties of Monolingual BERTs with Typological Classification among Languages (Ruzzetti et al., Findings 2023)
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PDF:
https://aclanthology.org/2023.findings-emnlp.963.pdf