Hierarchical Modeling of Global Context for Document-Level Neural Machine Translation

Xin Tan, Longyin Zhang, Deyi Xiong, Guodong Zhou


Abstract
Document-level machine translation (MT) remains challenging due to the difficulty in efficiently using document context for translation. In this paper, we propose a hierarchical model to learn the global context for document-level neural machine translation (NMT). This is done through a sentence encoder to capture intra-sentence dependencies and a document encoder to model document-level inter-sentence consistency and coherence. With this hierarchical architecture, we feedback the extracted global document context to each word in a top-down fashion to distinguish different translations of a word according to its specific surrounding context. In addition, since large-scale in-domain document-level parallel corpora are usually unavailable, we use a two-step training strategy to take advantage of a large-scale corpus with out-of-domain parallel sentence pairs and a small-scale corpus with in-domain parallel document pairs to achieve the domain adaptability. Experimental results on several benchmark corpora show that our proposed model can significantly improve document-level translation performance over several strong NMT baselines.
Anthology ID:
D19-1168
Volume:
Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP)
Month:
November
Year:
2019
Address:
Hong Kong, China
Editors:
Kentaro Inui, Jing Jiang, Vincent Ng, Xiaojun Wan
Venues:
EMNLP | IJCNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
1576–1585
Language:
URL:
https://aclanthology.org/D19-1168
DOI:
10.18653/v1/D19-1168
Bibkey:
Cite (ACL):
Xin Tan, Longyin Zhang, Deyi Xiong, and Guodong Zhou. 2019. Hierarchical Modeling of Global Context for Document-Level Neural Machine Translation. In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP), pages 1576–1585, Hong Kong, China. Association for Computational Linguistics.
Cite (Informal):
Hierarchical Modeling of Global Context for Document-Level Neural Machine Translation (Tan et al., EMNLP-IJCNLP 2019)
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PDF:
https://aclanthology.org/D19-1168.pdf