Beyond Correlation: Interpretable Evaluation of Machine Translation Metrics

Stefano Perrella, Lorenzo Proietti, Pere-Lluís Huguet Cabot, Edoardo Barba, Roberto Navigli


Abstract
Machine Translation (MT) evaluation metrics assess translation quality automatically. Recently, researchers have employed MT metrics for various new use cases, such as data filtering and translation re-ranking. However, most MT metrics return assessments as scalar scores that are difficult to interpret, posing a challenge to making informed design choices. Moreover, MT metrics’ capabilities have historically been evaluated using correlation with human judgment, which, despite its efficacy, falls short of providing intuitive insights into metric performance, especially in terms of new metric use cases. To address these issues, we introduce an interpretable evaluation framework for MT metrics. Within this framework, we evaluate metrics in two scenarios that serve as proxies for the data filtering and translation re-ranking use cases. Furthermore, by measuring the performance of MT metrics using Precision, Recall, and F-score, we offer clearer insights into their capabilities than correlation with human judgments. Finally, we raise concerns regarding the reliability of manually curated data following the Direct Assessments+Scalar Quality Metrics (DA+SQM) guidelines, reporting a notably low agreement with Multidimensional Quality Metrics (MQM) annotations.
Anthology ID:
2024.emnlp-main.1152
Volume:
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2024
Address:
Miami, Florida, USA
Editors:
Yaser Al-Onaizan, Mohit Bansal, Yun-Nung Chen
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
20689–20714
Language:
URL:
https://aclanthology.org/2024.emnlp-main.1152
DOI:
Bibkey:
Cite (ACL):
Stefano Perrella, Lorenzo Proietti, Pere-Lluís Huguet Cabot, Edoardo Barba, and Roberto Navigli. 2024. Beyond Correlation: Interpretable Evaluation of Machine Translation Metrics. In Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing, pages 20689–20714, Miami, Florida, USA. Association for Computational Linguistics.
Cite (Informal):
Beyond Correlation: Interpretable Evaluation of Machine Translation Metrics (Perrella et al., EMNLP 2024)
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PDF:
https://aclanthology.org/2024.emnlp-main.1152.pdf