Towards Opening the Black Box of Neural Machine Translation: Source and Target Interpretations of the Transformer

Javier Ferrando, Gerard I. Gállego, Belen Alastruey, Carlos Escolano, Marta R. Costa-jussà


Abstract
In Neural Machine Translation (NMT), each token prediction is conditioned on the source sentence and the target prefix (what has been previously translated at a decoding step). However, previous work on interpretability in NMT has mainly focused solely on source sentence tokens’ attributions. Therefore, we lack a full understanding of the influences of every input token (source sentence and target prefix) in the model predictions. In this work, we propose an interpretability method that tracks input tokens’ attributions for both contexts. Our method, which can be extended to any encoder-decoder Transformer-based model, allows us to better comprehend the inner workings of current NMT models. We apply the proposed method to both bilingual and multilingual Transformers and present insights into their behaviour.
Anthology ID:
2022.emnlp-main.599
Volume:
Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing
Month:
December
Year:
2022
Address:
Abu Dhabi, United Arab Emirates
Editors:
Yoav Goldberg, Zornitsa Kozareva, Yue Zhang
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
8756–8769
Language:
URL:
https://aclanthology.org/2022.emnlp-main.599
DOI:
10.18653/v1/2022.emnlp-main.599
Bibkey:
Cite (ACL):
Javier Ferrando, Gerard I. Gállego, Belen Alastruey, Carlos Escolano, and Marta R. Costa-jussà. 2022. Towards Opening the Black Box of Neural Machine Translation: Source and Target Interpretations of the Transformer. In Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing, pages 8756–8769, Abu Dhabi, United Arab Emirates. Association for Computational Linguistics.
Cite (Informal):
Towards Opening the Black Box of Neural Machine Translation: Source and Target Interpretations of the Transformer (Ferrando et al., EMNLP 2022)
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PDF:
https://preview.aclanthology.org/landing_page/2022.emnlp-main.599.pdf