COMET for Low-Resource Machine Translation Evaluation: A Case Study of English-Maltese and Spanish-Basque

Júlia Falcão, Claudia Borg, Nora Aranberri, Kurt Abela


Abstract
Trainable metrics for machine translation evaluation have been scoring the highest correlations with human judgements in the latest meta-evaluations, outperforming traditional lexical overlap metrics such as BLEU, which is still widely used despite its well-known shortcomings. In this work we look at COMET, a prominent neural evaluation system proposed in 2020, to analyze the extent of its language support restrictions, and to investigate strategies to extend this support to new, under-resourced languages. Our case study focuses on English-Maltese and Spanish-Basque. We run a crowd-based evaluation campaign to collect direct assessments and use the annotated dataset to evaluate COMET-22, further fine-tune it, and to train COMET models from scratch for the two language pairs. Our analysis suggests that COMET’s performance can be improved with fine-tuning, and that COMET can be highly susceptible to the distribution of scores in the training data, which especially impacts low-resource scenarios.
Anthology ID:
2024.lrec-main.315
Volume:
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)
Month:
May
Year:
2024
Address:
Torino, Italia
Editors:
Nicoletta Calzolari, Min-Yen Kan, Veronique Hoste, Alessandro Lenci, Sakriani Sakti, Nianwen Xue
Venues:
LREC | COLING
SIG:
Publisher:
ELRA and ICCL
Note:
Pages:
3553–3565
Language:
URL:
https://aclanthology.org/2024.lrec-main.315
DOI:
Bibkey:
Cite (ACL):
Júlia Falcão, Claudia Borg, Nora Aranberri, and Kurt Abela. 2024. COMET for Low-Resource Machine Translation Evaluation: A Case Study of English-Maltese and Spanish-Basque. In Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024), pages 3553–3565, Torino, Italia. ELRA and ICCL.
Cite (Informal):
COMET for Low-Resource Machine Translation Evaluation: A Case Study of English-Maltese and Spanish-Basque (Falcão et al., LREC-COLING 2024)
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PDF:
https://aclanthology.org/2024.lrec-main.315.pdf