Improving Multilingual Models with Language-Clustered Vocabularies

Hyung Won Chung, Dan Garrette, Kiat Chuan Tan, Jason Riesa


Abstract
State-of-the-art multilingual models depend on vocabularies that cover all of the languages the model will expect to see at inference time, but the standard methods for generating those vocabularies are not ideal for massively multilingual applications. In this work, we introduce a novel procedure for multilingual vocabulary generation that combines the separately trained vocabularies of several automatically derived language clusters, thus balancing the trade-off between cross-lingual subword sharing and language-specific vocabularies. Our experiments show improvements across languages on key multilingual benchmark tasks TyDi QA (+2.9 F1), XNLI (+2.1%), and WikiAnn NER (+2.8 F1) and factor of 8 reduction in out-of-vocabulary rate, all without increasing the size of the model or data.
Anthology ID:
2020.emnlp-main.367
Volume:
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)
Month:
November
Year:
2020
Address:
Online
Editors:
Bonnie Webber, Trevor Cohn, Yulan He, Yang Liu
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
4536–4546
Language:
URL:
https://aclanthology.org/2020.emnlp-main.367
DOI:
10.18653/v1/2020.emnlp-main.367
Bibkey:
Cite (ACL):
Hyung Won Chung, Dan Garrette, Kiat Chuan Tan, and Jason Riesa. 2020. Improving Multilingual Models with Language-Clustered Vocabularies. In Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP), pages 4536–4546, Online. Association for Computational Linguistics.
Cite (Informal):
Improving Multilingual Models with Language-Clustered Vocabularies (Chung et al., EMNLP 2020)
Copy Citation:
PDF:
https://aclanthology.org/2020.emnlp-main.367.pdf
Video:
 https://slideslive.com/38939272
Data
XNLI