Quality-Aware Translation Models: Efficient Generation and Quality Estimation in a Single Model

Christian Tomani, David Vilar, Markus Freitag, Colin Cherry, Subhajit Naskar, Mara Finkelstein, Xavier Garcia, Daniel Cremers


Abstract
Maximum-a-posteriori (MAP) decoding is the most widely used decoding strategy for neural machine translation (NMT) models. The underlying assumption is that model probability correlates well with human judgment, with better translations getting assigned a higher score by the model. However, research has shown that this assumption does not always hold, and generation quality can be improved by decoding to optimize a utility function backed by a metric or quality-estimation signal, as is done by Minimum Bayes Risk (MBR) or Quality-Aware decoding. The main disadvantage of these approaches is that they require an additional model to calculate the utility function during decoding, significantly increasing the computational cost. In this paper, we propose to make the NMT models themselves quality-aware by training them to estimate the quality of their own output. Using this approach for MBR decoding we can drastically reduce the size of the candidate list, resulting in a speed-up of two-orders of magnitude. When applying our method to MAP decoding we obtain quality gains similar or even superior to quality reranking approaches, but with the efficiency of single pass decoding.
Anthology ID:
2024.acl-long.836
Volume:
Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
August
Year:
2024
Address:
Bangkok, Thailand
Editors:
Lun-Wei Ku, Andre Martins, Vivek Srikumar
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
15660–15679
Language:
URL:
https://aclanthology.org/2024.acl-long.836
DOI:
10.18653/v1/2024.acl-long.836
Bibkey:
Cite (ACL):
Christian Tomani, David Vilar, Markus Freitag, Colin Cherry, Subhajit Naskar, Mara Finkelstein, Xavier Garcia, and Daniel Cremers. 2024. Quality-Aware Translation Models: Efficient Generation and Quality Estimation in a Single Model. In Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 15660–15679, Bangkok, Thailand. Association for Computational Linguistics.
Cite (Informal):
Quality-Aware Translation Models: Efficient Generation and Quality Estimation in a Single Model (Tomani et al., ACL 2024)
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PDF:
https://preview.aclanthology.org/autopr/2024.acl-long.836.pdf