CoTERM: A Consistency-Oriented Term Metric for MT System Evaluation

Amir Hazem, Kyo Kageura


Abstract
Proper treatment of terms is an important and critical aspect in machine translation. It is therefore necessary to use appropriate metrics to evaluate MT system outputs from terminology perspective. However, despite the great improvements witnessed in the recent NMT and LLM models, MT system evaluation metrics that shed light on specific aspects of term translations are yet to be fully explored. In this paper, we propose CoTERM, a new metric for automatic evaluation of term translations based on the Herfindahl-Hirshman Index (HHI). CoTERM measures target term closeness to one or more reference translations, taking into account the fundamental criteria for translating terms, i.e. (i) accuracy; (ii) consistency at document or corpus levels; and (iii) appropriateness to the domain conventions with regard to term variations. The proposed metric correlates strongly with human raters, and empirical evaluations of a wide range of NMTs and LLMs show that the best MT systems in standard metrics are not necessarily the best at treating terms. CoTERM is thus shown to be highly useful for diagnosing MT systems’ term translation performance and conveniently seen as complementary to generic measures for MT system evaluations.
Anthology ID:
2026.lrec-main.682
Volume:
Proceedings of the Fifteenth Language Resources and Evaluation Conference
Month:
May
Year:
2026
Address:
Palma de Mallorca, Spain
Editors:
Stelios Piperidis, Núria Bel, Henk van den Heuvel, Nancy Ide, Simon Krek, Antonio Toral
Venue:
LREC
SIG:
Publisher:
ELRA Language Resource Association
Note:
Pages:
8639–8661
Language:
URL:
https://preview.aclanthology.org/ingest-lrec/2026.lrec-main.682/
DOI:
Bibkey:
Cite (ACL):
Amir Hazem and Kyo Kageura. 2026. CoTERM: A Consistency-Oriented Term Metric for MT System Evaluation. International Conference on Language Resources and Evaluation, main:8639–8661.
Cite (Informal):
CoTERM: A Consistency-Oriented Term Metric for MT System Evaluation (Hazem & Kageura, LREC 2026)
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PDF:
https://preview.aclanthology.org/ingest-lrec/2026.lrec-main.682.pdf