Learning from a Friend: Improving Event Extraction via Self-Training with Feedback from Abstract Meaning Representation

Zhiyang Xu, Jay Yoon Lee, Lifu Huang


Abstract
Data scarcity has been the main factor that hinders the progress of event extraction. To overcome this issue, we propose a Self-Training with Feedback (STF) framework that leverages the large-scale unlabeled data and acquires feedback for each new event prediction from the unlabeled data by comparing it to the Abstract Meaning Representation (AMR) graph of the same sentence. Specifically, STF consists of (1) a base event extraction model trained on existing event annotations and then applied to large-scale unlabeled corpora to predict new event mentions as pseudo training samples, and (2) a novel scoring model that takes in each new predicted event trigger, an argument, its argument role, as well as their paths in the AMR graph to estimate a compatibility score indicating the correctness of the pseudo label. The compatibility scores further act as feedback to encourage or discourage the model learning on the pseudo labels during self-training. Experimental results on three benchmark datasets, including ACE05-E, ACE05-E+, and ERE, demonstrate the effectiveness of the STF framework on event extraction, especially event argument extraction, with significant performance gain over the base event extraction models and strong baselines. Our experimental analysis further shows that STF is a generic framework as it can be applied to improve most, if not all, event extraction models by leveraging large-scale unlabeled data, even when high-quality AMR graph annotations are not available.
Anthology ID:
2023.findings-acl.662
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:
10421–10437
Language:
URL:
https://aclanthology.org/2023.findings-acl.662
DOI:
10.18653/v1/2023.findings-acl.662
Bibkey:
Cite (ACL):
Zhiyang Xu, Jay Yoon Lee, and Lifu Huang. 2023. Learning from a Friend: Improving Event Extraction via Self-Training with Feedback from Abstract Meaning Representation. In Findings of the Association for Computational Linguistics: ACL 2023, pages 10421–10437, Toronto, Canada. Association for Computational Linguistics.
Cite (Informal):
Learning from a Friend: Improving Event Extraction via Self-Training with Feedback from Abstract Meaning Representation (Xu et al., Findings 2023)
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PDF:
https://aclanthology.org/2023.findings-acl.662.pdf
Video:
 https://aclanthology.org/2023.findings-acl.662.mp4