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CopyMTL: Copy Mechanism for Joint Extraction of Entities and Relations with Multi-Task Learning

Proceedings of the AAAI Conference on Artificial IntelligencePublished 3 April 2020Open access
Daojian Zeng, Ranran Haoran Zhang, Qianying Liu
Citations199
SJR score0.13
SNIP0.00
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TL;DR

A detailed analysis of the reasons behind the inaccurate entity extraction problem is given, and a simple but extremely effective model structure is proposed to solve this problem, called CopyMTL, to allow the model to predict multi-token entities.

Abstract

Joint extraction of entities and relations has received significant attention due to its potential of providing higher performance for both tasks. Among existing methods, CopyRE is effective and novel, which uses a sequence-to-sequence framework and copy mechanism to directly generate the relation triplets. However, it suffers from two fatal problems. The model is extremely weak at differing the head and tail entity, resulting in inaccurate entity extraction. It also cannot predict multi-token entities (e.g. Steven Jobs). To address these problems, we give a detailed analysis of the reasons behind the inaccurate entity extraction problem, and then propose a simple but extremely effective model structure to solve this problem. In addition, we propose a multi-task learning framework equipped with copy mechanism, called CopyMTL, to allow the model to predict multi-token entities. Experiments reveal the problems of CopyRE and show that our model achieves significant improvement over the current state-of-the-art method by 9% in NYT and 16% in WebNLG (F1 score). Our code is available at https://github.com/WindChimeRan/CopyMTL

Keywords

Computer ScienceDecision Sciences