CLewR: Curriculum Learning with Restarts for Machine Translation Preference Learning

Alexandra Dragomir, Florin Brad, Radu Tudor Ionescu


Abstract
Large language models (LLMs) have demonstrated competitive performance in zero-shot multilingual machine translation (MT). Some follow-up works further improved MT performance via preference optimization, but they leave a key aspect largely underexplored: the order in which data samples are given during training. We address this topic by integrating curriculum learning into various state-of-the-art preference optimization algorithms to boost MT performance. We introduce a novel curriculum learning strategy with restarts (CLewR), which reiterates easy-to-hard curriculum multiple times during training to effectively mitigate the catastrophic forgetting of easy examples. We demonstrate consistent gains across several model families (Gemma2, Qwen2.5, Llama3.1) and preference optimization techniques. We publicly release our code at https://github.com/alexandra-dragomir/CLewR.
Anthology ID:
2026.findings-acl.1024
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
20485–20496
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1024/
DOI:
Bibkey:
Cite (ACL):
Alexandra Dragomir, Florin Brad, and Radu Tudor Ionescu. 2026. CLewR: Curriculum Learning with Restarts for Machine Translation Preference Learning. In Findings of the Association for Computational Linguistics: ACL 2026, pages 20485–20496, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
CLewR: Curriculum Learning with Restarts for Machine Translation Preference Learning (Dragomir et al., Findings 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1024.pdf
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