Mind the Gap... or Not? How Translation Errors and Evaluation Details Skew Multilingual Results

Jan-Thorsten Peter, David Vilar, Tobias Domhan, Dan Malkin, Markus Freitag


Abstract
Most current large language models (LLMs) support a wide variety of languages in addition to English, including high-resource languages (e.g. German, Chinese, French), as well as low-resource ones (e.g. Swahili, Telugu). In addition they have shown impressive capabilities in different domains, like coding, science and math. In this paper, taking math as an example domain, we study the performance of different LLMs across languages. Experimental results show that there exists a non-negligible and consistent gap in the performance of the models across languages. Interestingly, and somewhat against expectations, the gap exists for both high- and low-resource languages. These results should impact further research into cross-lingual capability generalization for next generation LLMs. Or they would, if it weren’t for the fact that they are false. By analyzing one of the standard multilingual math benchmarks (MGSM), we determine that several translation errors are present in the data. Furthermore, the lack of standardized answer extraction from LLM outputs further influences the final results. We propose a method for semi-automatic quality assurance to address the first issue at scale, and give recommendations to address the second one. Combining these two approaches we show that the aforementioned language gap mostly disappears, leading to completely different conclusions from our research. We additionally release the corrected dataset to the community.
Anthology ID:
2026.gem-main.22
Volume:
Proceedings of the Fifth Workshop on Generation, Evaluation and Metrics (GEM)
Month:
July
Year:
2026
Address:
San Diego, California, USA
Editors:
Simon Mille, Sebastian Gehrmann, Patrícia Schmidtová, Ondřej Dušek, Marzieh Fadaee, Kyle Lo, Enrico Santus, Gabriel Stanovsky
Venues:
GEM | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
191–204
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.gem-main.22/
DOI:
Bibkey:
Cite (ACL):
Jan-Thorsten Peter, David Vilar, Tobias Domhan, Dan Malkin, and Markus Freitag. 2026. Mind the Gap... or Not? How Translation Errors and Evaluation Details Skew Multilingual Results. In Proceedings of the Fifth Workshop on Generation, Evaluation and Metrics (GEM), pages 191–204, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
Mind the Gap… or Not? How Translation Errors and Evaluation Details Skew Multilingual Results (Peter et al., GEM 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.gem-main.22.pdf