In-Context Example Selection via Similarity Search Improves Low-Resource Machine Translation

Armel Randy Zebaze, Benoît Sagot, Rachel Bawden


Abstract
The ability of generative large language models (LLMs) to perform in-context learning has given rise to a large body of research into how best to prompt models for various natural language processing tasks. In this paper, we focus on machine translation (MT), a task that has been shown to benefit from in-context translation examples. However no systematic studies have been published on how best to select examples, and mixed results have been reported on the usefulness of similarity-based selection over random selection, although these results have mainly been shown for high-resource languages only. We provide a study covering multiple LLMs and in-context example retrieval strategies. Contrarily to previously published results, we find that retrieval based on sentence embedding similarity can improve MT, especially for low-resource language directions, and we also discuss the balance between selection pool diversity and quality. Code and outputs will be made freely available.
Anthology ID:
2025.findings-naacl.68
Volume:
Findings of the Association for Computational Linguistics: NAACL 2025
Month:
April
Year:
2025
Address:
Albuquerque, New Mexico
Editors:
Luis Chiruzzo, Alan Ritter, Lu Wang
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
1222–1252
Language:
URL:
https://preview.aclanthology.org/fix-sig-urls/2025.findings-naacl.68/
DOI:
Bibkey:
Cite (ACL):
Armel Randy Zebaze, Benoît Sagot, and Rachel Bawden. 2025. In-Context Example Selection via Similarity Search Improves Low-Resource Machine Translation. In Findings of the Association for Computational Linguistics: NAACL 2025, pages 1222–1252, Albuquerque, New Mexico. Association for Computational Linguistics.
Cite (Informal):
In-Context Example Selection via Similarity Search Improves Low-Resource Machine Translation (Zebaze et al., Findings 2025)
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PDF:
https://preview.aclanthology.org/fix-sig-urls/2025.findings-naacl.68.pdf