Hyperspherical Multi-Prototype with Optimal Transport for Event Argument Extraction
Guangjun Zhang, Hu Zhang, YuJie Wang, Ru Li, Hongye Tan, Jiye Liang
Abstract
Event Argument Extraction (EAE) aims to extract arguments for specified events from a text. Previous research has mainly focused on addressing long-distance dependencies of arguments, modeling co-occurrence relationships between roles and events, but overlooking potential inductive biases: (i) semantic differences among arguments of the same type and (ii) large margin separation between arguments of the different types. Inspired by prototype networks, we introduce a new model named HMPEAE, which takes the two inductive biases above as targets to locate prototypes and guide the model to learn argument representations based on these prototypes.Specifically, we set multiple prototypes to represent each role to capture intra-class differences. Simultaneously, we use hypersphere as the output space for prototypes, defining large margin separation between prototypes to encourage the model to learn significant differences between different types of arguments effectively.We solve the “argument-prototype” assignment as an optimal transport problem to optimize the argument representation and minimize the absolute distance between arguments and prototypes to achieve compactness within sub-clusters. Experimental results on the RAMS and WikiEvents datasets show that HMPEAE achieves state-of-the-art performances.- Anthology ID:
- 2024.acl-long.502
- Volume:
- Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
- Month:
- August
- Year:
- 2024
- Address:
- Bangkok, Thailand
- Editors:
- Lun-Wei Ku, Andre Martins, Vivek Srikumar
- Venue:
- ACL
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 9271–9284
- Language:
- URL:
- https://aclanthology.org/2024.acl-long.502
- DOI:
- 10.18653/v1/2024.acl-long.502
- Cite (ACL):
- Guangjun Zhang, Hu Zhang, YuJie Wang, Ru Li, Hongye Tan, and Jiye Liang. 2024. Hyperspherical Multi-Prototype with Optimal Transport for Event Argument Extraction. In Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 9271–9284, Bangkok, Thailand. Association for Computational Linguistics.
- Cite (Informal):
- Hyperspherical Multi-Prototype with Optimal Transport for Event Argument Extraction (Zhang et al., ACL 2024)
- PDF:
- https://preview.aclanthology.org/dois-2013-emnlp/2024.acl-long.502.pdf