Incremental Event Detection via Knowledge Consolidation Networks

Pengfei Cao, Yubo Chen, Jun Zhao, Taifeng Wang


Abstract
Conventional approaches to event detection usually require a fixed set of pre-defined event types. Such a requirement is often challenged in real-world applications, as new events continually occur. Due to huge computation cost and storage budge, it is infeasible to store all previous data and re-train the model with all previous data and new data, every time new events arrive. We formulate such challenging scenarios as incremental event detection, which requires a model to learn new classes incrementally without performance degradation on previous classes. However, existing incremental learning methods cannot handle semantic ambiguity and training data imbalance problems between old and new classes in the task of incremental event detection. In this paper, we propose a Knowledge Consolidation Network (KCN) to address the above issues. Specifically, we devise two components, prototype enhanced retrospection and hierarchical distillation, to mitigate the adverse effects of semantic ambiguity and class imbalance, respectively. Experimental results demonstrate the effectiveness of the proposed method, outperforming the state-of-the-art model by 19% and 13.4% of whole F1 score on ACE benchmark and TAC KBP benchmark, respectively.
Anthology ID:
2020.emnlp-main.52
Volume:
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)
Month:
November
Year:
2020
Address:
Online
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
707–717
Language:
URL:
https://aclanthology.org/2020.emnlp-main.52
DOI:
10.18653/v1/2020.emnlp-main.52
Bibkey:
Cite (ACL):
Pengfei Cao, Yubo Chen, Jun Zhao, and Taifeng Wang. 2020. Incremental Event Detection via Knowledge Consolidation Networks. In Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP), pages 707–717, Online. Association for Computational Linguistics.
Cite (Informal):
Incremental Event Detection via Knowledge Consolidation Networks (Cao et al., EMNLP 2020)
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PDF:
https://aclanthology.org/2020.emnlp-main.52.pdf
Video:
 https://slideslive.com/38938979