More Embeddings, Better Sequence Labelers?

Xinyu Wang, Yong Jiang, Nguyen Bach, Tao Wang, Zhongqiang Huang, Fei Huang, Kewei Tu

Abstract
Recent work proposes a family of contextual embeddings that significantly improves the accuracy of sequence labelers over non-contextual embeddings. However, there is no definite conclusion on whether we can build better sequence labelers by combining different kinds of embeddings in various settings. In this paper, we conduct extensive experiments on 3 tasks over 18 datasets and 8 languages to study the accuracy of sequence labeling with various embedding concatenations and make three observations: (1) concatenating more embedding variants leads to better accuracy in rich-resource and cross-domain settings and some conditions of low-resource settings; (2) concatenating contextual sub-word embeddings with contextual character embeddings hurts the accuracy in extremely low-resource settings; (3) based on the conclusion of (1), concatenating additional similar contextual embeddings cannot lead to further improvements. We hope these conclusions can help people build stronger sequence labelers in various settings.
Anthology ID:
2020.findings-emnlp.356
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2020
Month:
November
Year:
2020
Address:
Online
Editors:
Trevor Cohn, Yulan He, Yang Liu
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
3992–4006
Language:
URL:
https://aclanthology.org/2020.findings-emnlp.356
DOI:
10.18653/v1/2020.findings-emnlp.356
Bibkey:
Cite (ACL):
Xinyu Wang, Yong Jiang, Nguyen Bach, Tao Wang, Zhongqiang Huang, Fei Huang, and Kewei Tu. 2020. More Embeddings, Better Sequence Labelers?. In Findings of the Association for Computational Linguistics: EMNLP 2020, pages 3992–4006, Online. Association for Computational Linguistics.
Cite (Informal):
More Embeddings, Better Sequence Labelers? (Wang et al., Findings 2020)
Copy Citation:
PDF:
https://preview.aclanthology.org/dois-2013-emnlp/2020.findings-emnlp.356.pdf
Data
CoNLL, CoNLL 2003
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