Parameter Sharing Methods for Multilingual Self-Attentional Translation Models

Devendra Sachan, Graham Neubig


Abstract
In multilingual neural machine translation, it has been shown that sharing a single translation model between multiple languages can achieve competitive performance, sometimes even leading to performance gains over bilingually trained models. However, these improvements are not uniform; often multilingual parameter sharing results in a decrease in accuracy due to translation models not being able to accommodate different languages in their limited parameter space. In this work, we examine parameter sharing techniques that strike a happy medium between full sharing and individual training, specifically focusing on the self-attentional Transformer model. We find that the full parameter sharing approach leads to increases in BLEU scores mainly when the target languages are from a similar language family. However, even in the case where target languages are from different families where full parameter sharing leads to a noticeable drop in BLEU scores, our proposed methods for partial sharing of parameters can lead to substantial improvements in translation accuracy.
Anthology ID:
W18-6327
Volume:
Proceedings of the Third Conference on Machine Translation: Research Papers
Month:
October
Year:
2018
Address:
Brussels, Belgium
Venues:
EMNLP | WMT | WS
SIG:
SIGMT
Publisher:
Association for Computational Linguistics
Note:
Pages:
261–271
Language:
URL:
https://aclanthology.org/W18-6327
DOI:
10.18653/v1/W18-6327
Bibkey:
Cite (ACL):
Devendra Sachan and Graham Neubig. 2018. Parameter Sharing Methods for Multilingual Self-Attentional Translation Models. In Proceedings of the Third Conference on Machine Translation: Research Papers, pages 261–271, Brussels, Belgium. Association for Computational Linguistics.
Cite (Informal):
Parameter Sharing Methods for Multilingual Self-Attentional Translation Models (Sachan & Neubig, 2018)
Copy Citation:
PDF:
https://preview.aclanthology.org/update-css-js/W18-6327.pdf
Code
 DevSinghSachan/multilingual_nmt