An Exploration of Encoder-Decoder Approaches to Multi-Label Classification for Legal and Biomedical Text

Yova Kementchedjhieva, Ilias Chalkidis


Abstract
Standard methods for multi-label text classification largely rely on encoder-only pre-trained language models, whereas encoder-decoder models have proven more effective in other classification tasks. In this study, we compare four methods for multi-label classification, two based on an encoder only, and two based on an encoder-decoder. We carry out experiments on four datasets—two in the legal domain and two in the biomedical domain, each with two levels of label granularity— and always depart from the same pre-trained model, T5. Our results show that encoder-decoder methods outperform encoder-only methods, with a growing advantage on more complex datasets and labeling schemes of finer granularity. Using encoder-decoder models in a non-autoregressive fashion, in particular, yields the best performance overall, so we further study this approach through ablations to better understand its strengths.
Anthology ID:
2023.findings-acl.360
Volume:
Findings of the Association for Computational Linguistics: ACL 2023
Month:
July
Year:
2023
Address:
Toronto, Canada
Editors:
Anna Rogers, Jordan Boyd-Graber, Naoaki Okazaki
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
5828–5843
Language:
URL:
https://aclanthology.org/2023.findings-acl.360
DOI:
10.18653/v1/2023.findings-acl.360
Bibkey:
Cite (ACL):
Yova Kementchedjhieva and Ilias Chalkidis. 2023. An Exploration of Encoder-Decoder Approaches to Multi-Label Classification for Legal and Biomedical Text. In Findings of the Association for Computational Linguistics: ACL 2023, pages 5828–5843, Toronto, Canada. Association for Computational Linguistics.
Cite (Informal):
An Exploration of Encoder-Decoder Approaches to Multi-Label Classification for Legal and Biomedical Text (Kementchedjhieva & Chalkidis, Findings 2023)
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PDF:
https://preview.aclanthology.org/naacl24-info/2023.findings-acl.360.pdf