Translate Smart, not Hard: Cascaded Translation Systems with Quality-Aware Deferral

António Farinhas, Nuno M Guerreiro, Sweta Agrawal, Ricardo Rei, Andre Martins


Abstract
Larger models often outperform smaller ones but come with high computational costs. Cascading offers a potential solution. By default, it uses smaller models and defers only some instances to larger, more powerful models. However, designing effective deferral rules remains a challenge. In this paper, we propose a simple yet effective approach for machine translation, using existing quality estimation (QE) metrics as deferral rules. We show that QE-based deferral allows a cascaded system to match the performance of a larger model while invoking it for a small fraction (30% to 50%) of the examples, significantly reducing computational costs. We validate this approach through both automatic and human evaluation.
Anthology ID:
2025.emnlp-main.1358
Volume:
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
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Pages:
26730–26744
Language:
URL:
https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-main.1358/
DOI:
Bibkey:
Cite (ACL):
António Farinhas, Nuno M Guerreiro, Sweta Agrawal, Ricardo Rei, and Andre Martins. 2025. Translate Smart, not Hard: Cascaded Translation Systems with Quality-Aware Deferral. In Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing, pages 26730–26744, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
Translate Smart, not Hard: Cascaded Translation Systems with Quality-Aware Deferral (Farinhas et al., EMNLP 2025)
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https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-main.1358.pdf
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