Autoregressive Structured Prediction with Language Models

Tianyu Liu, Yuchen Eleanor Jiang, Nicholas Monath, Ryan Cotterell, Mrinmaya Sachan


Abstract
Recent years have seen a paradigm shift in NLP towards using pretrained language models (PLM) for a wide range of tasks. However, there are many difficult design decisions to represent structures (e.g. tagged text, coreference chains) in a way such that they can be captured by PLMs. Prior work on structured prediction with PLMs typically flattens the structured output into a sequence, which limits the quality of structural information being learned and leads to inferior performance compared to classic discriminative models. In this work, we describe an approach to model structures as sequences of actions in an autoregressive manner with PLMs, allowing in-structure dependencies to be learned without any loss. Our approach achieves the new state-of-the-art on all the structured prediction tasks we looked at, namely, named entity recognition, end-to-end relation extraction, and coreference resolution.
Anthology ID:
2022.findings-emnlp.70
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2022
Month:
December
Year:
2022
Address:
Abu Dhabi, United Arab Emirates
Editors:
Yoav Goldberg, Zornitsa Kozareva, Yue Zhang
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
993–1005
Language:
URL:
https://aclanthology.org/2022.findings-emnlp.70
DOI:
10.18653/v1/2022.findings-emnlp.70
Bibkey:
Cite (ACL):
Tianyu Liu, Yuchen Eleanor Jiang, Nicholas Monath, Ryan Cotterell, and Mrinmaya Sachan. 2022. Autoregressive Structured Prediction with Language Models. In Findings of the Association for Computational Linguistics: EMNLP 2022, pages 993–1005, Abu Dhabi, United Arab Emirates. Association for Computational Linguistics.
Cite (Informal):
Autoregressive Structured Prediction with Language Models (Liu et al., Findings 2022)
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PDF:
https://preview.aclanthology.org/nschneid-patch-5/2022.findings-emnlp.70.pdf