Towards Reliable Multilingual Judge Models: An Empirical Study

Irune Zubiaga, Aitor Soroa, Rodrigo Agerri


Abstract
Large language models (LLMs) are increasingly used for automatic evaluation of generated text, but most work focuses on English. Extending LLM-based evaluation to multilingual settings is challenging, especially for low-resource languages or when in-domain data is scarce. This work explores how an English evaluation corpus can serve to evaluate other languages, both when in-domain data is available for fine-tuning and when it is not. We systematically analyze English, Spanish, and Basque, representing high-, mid-, and low-resource languages, considering instruction translation, monolingual versus multilingual supervision, and model size. Our results reveal key trade-offs: When in-domain data is available, fine-tuned smaller models can achieve performance comparable to proprietary models, whereas zero-shot evaluation with larger models proves more effective in out-of-domain settings. We also observe that fine-tuning on out-of-domain data can adversely affect model performance. These findings provide practical guidance for building efficient, reliable multilingual evaluation pipelines. The data and code are publicly available at hitz-zentroa/mJudge .
Anthology ID:
2026.findings-emnlp.32
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
630–644
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.32/
DOI:
Bibkey:
Cite (ACL):
Irune Zubiaga, Aitor Soroa, and Rodrigo Agerri. 2026. Towards Reliable Multilingual Judge Models: An Empirical Study. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 630–644, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Towards Reliable Multilingual Judge Models: An Empirical Study (Zubiaga et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.32.pdf