Generalised Unsupervised Domain Adaptation of Neural Machine Translation with Cross-Lingual Data Selection

Thuy-Trang Vu, Xuanli He, Dinh Phung, Gholamreza Haffari


Abstract
This paper considers the unsupervised domain adaptation problem for neural machine translation (NMT), where we assume the access to only monolingual text in either the source or target language in the new domain. We propose a cross-lingual data selection method to extract in-domain sentences in the missing language side from a large generic monolingual corpus. Our proposed method trains an adaptive layer on top of multilingual BERT by contrastive learning to align the representation between the source and target language. This then enables the transferability of the domain classifier between the languages in a zero-shot manner. Once the in-domain data is detected by the classifier, the NMT model is then adapted to the new domain by jointly learning translation and domain discrimination tasks. We evaluate our cross-lingual data selection method on NMT across five diverse domains in three language pairs, as well as a real-world scenario of translation for COVID-19. The results show that our proposed method outperforms other selection baselines up to +1.5 BLEU score.
Anthology ID:
2021.emnlp-main.268
Volume:
Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2021
Address:
Online and Punta Cana, Dominican Republic
Editors:
Marie-Francine Moens, Xuanjing Huang, Lucia Specia, Scott Wen-tau Yih
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
3335–3346
Language:
URL:
https://aclanthology.org/2021.emnlp-main.268
DOI:
10.18653/v1/2021.emnlp-main.268
Bibkey:
Cite (ACL):
Thuy-Trang Vu, Xuanli He, Dinh Phung, and Gholamreza Haffari. 2021. Generalised Unsupervised Domain Adaptation of Neural Machine Translation with Cross-Lingual Data Selection. In Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing, pages 3335–3346, Online and Punta Cana, Dominican Republic. Association for Computational Linguistics.
Cite (Informal):
Generalised Unsupervised Domain Adaptation of Neural Machine Translation with Cross-Lingual Data Selection (Vu et al., EMNLP 2021)
Copy Citation:
PDF:
https://preview.aclanthology.org/emnlp-22-attachments/2021.emnlp-main.268.pdf
Video:
 https://preview.aclanthology.org/emnlp-22-attachments/2021.emnlp-main.268.mp4
Code
 trangvu/guda