Previous works mostly focus on either multilingual or multi-domain aspects of neural machine translation (NMT). This paper investigates whether the domain information can be transferred across languages on the composition of multi-domain and multilingual NMT, particularly for the incomplete data condition where in-domain bitext is missing for some language pairs. Our results in the curated leave-one-domain-out experiments show that multi-domain multilingual (MDML) NMT can boost zero-shot translation performance up to +10 gains on BLEU, as well as aid the generalisation of multi-domain NMT to the missing domain. We also explore strategies for effective integration of multilingual and multi-domain NMT, including language and domain tag combination and auxiliary task training. We find that learning domain-aware representations and adding target-language tags to the encoder leads to effective MDML-NMT.

本文讨论了如何在多领域和多语言神经机器翻译 (MDML-NMT) 中跨语言传输领域信息，以提高零样本翻译性能和帮助域缺失的多领域 NMT 的泛化。通过组合多语言和多领域 NMT 及添加编码器目标语言标签等有效策略，实现了学习到有针对性的表示和提高性能的目的。

多域多语言神经机器翻译中，能否跨语言进行域传递？