Distilling Causal Effect from Miscellaneous Other-Class for Continual Named Entity Recognition

Junhao Zheng, Zhanxian Liang, Haibin Chen, Qianli Ma


Abstract
Continual Learning for Named Entity Recognition (CL-NER) aims to learn a growing number of entity types over time from a stream of data. However, simply learning Other-Class in the same way as new entity types amplifies the catastrophic forgetting and leads to a substantial performance drop. The main cause behind this is that Other-Class samples usually contain old entity types, and the old knowledge in these Other-Class samples is not preserved properly. Thanks to the causal inference, we identify that the forgetting is caused by the missing causal effect from the old data.To this end, we propose a unified causal framework to retrieve the causality from both new entity types and Other-Class.Furthermore, we apply curriculum learning to mitigate the impact of label noise and introduce a self-adaptive weight for balancing the causal effects between new entity types and Other-Class. Experimental results on three benchmark datasets show that our method outperforms the state-of-the-art method by a large margin. Moreover, our method can be combined with the existing state-of-the-art methods to improve the performance in CL-NER.
Anthology ID:
2022.emnlp-main.236
Volume:
Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing
Month:
December
Year:
2022
Address:
Abu Dhabi, United Arab Emirates
Editors:
Yoav Goldberg, Zornitsa Kozareva, Yue Zhang
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
3602–3615
Language:
URL:
https://aclanthology.org/2022.emnlp-main.236
DOI:
10.18653/v1/2022.emnlp-main.236
Bibkey:
Cite (ACL):
Junhao Zheng, Zhanxian Liang, Haibin Chen, and Qianli Ma. 2022. Distilling Causal Effect from Miscellaneous Other-Class for Continual Named Entity Recognition. In Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing, pages 3602–3615, Abu Dhabi, United Arab Emirates. Association for Computational Linguistics.
Cite (Informal):
Distilling Causal Effect from Miscellaneous Other-Class for Continual Named Entity Recognition (Zheng et al., EMNLP 2022)
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PDF:
https://aclanthology.org/2022.emnlp-main.236.pdf