cushLEPOR: customising hLEPOR metric using Optuna for higher agreement with human judgments or pre-trained language model LaBSE

Lifeng Han, Irina Sorokina, Gleb Erofeev, Serge Gladkoff


Abstract
Human evaluation has always been expensive while researchers struggle to trust the automatic metrics. To address this, we propose to customise traditional metrics by taking advantages of the pre-trained language models (PLMs) and the limited available human labelled scores. We first re-introduce the hLEPOR metric factors, followed by the Python version we developed (ported) which achieved the automatic tuning of the weighting parameters in hLEPOR metric. Then we present the customised hLEPOR (cushLEPOR) which uses Optuna hyper-parameter optimisation framework to fine-tune hLEPOR weighting parameters towards better agreement to pre-trained language models (using LaBSE) regarding the exact MT language pairs that cushLEPOR is deployed to. We also optimise cushLEPOR towards professional human evaluation data based on MQM and pSQM framework on English-German and Chinese-English language pairs. The experimental investigations show cushLEPOR boosts hLEPOR performances towards better agreements to PLMs like LABSE with much lower cost, and better agreements to human evaluations including MQM and pSQM scores, and yields much better performances than BLEU. Official results show that our submissions win three language pairs including English-German and Chinese-English on News domain via cushLEPOR(LM) and English-Russian on TED domain via hLEPOR. (data available at https://github.com/poethan/cushLEPOR)
Anthology ID:
2021.wmt-1.109
Volume:
Proceedings of the Sixth Conference on Machine Translation
Month:
November
Year:
2021
Address:
Online
Venues:
EMNLP | WMT
SIG:
SIGMT
Publisher:
Association for Computational Linguistics
Note:
Pages:
1014–1023
Language:
URL:
https://aclanthology.org/2021.wmt-1.109
DOI:
Bibkey:
Cite (ACL):
Lifeng Han, Irina Sorokina, Gleb Erofeev, and Serge Gladkoff. 2021. cushLEPOR: customising hLEPOR metric using Optuna for higher agreement with human judgments or pre-trained language model LaBSE. In Proceedings of the Sixth Conference on Machine Translation, pages 1014–1023, Online. Association for Computational Linguistics.
Cite (Informal):
cushLEPOR: customising hLEPOR metric using Optuna for higher agreement with human judgments or pre-trained language model LaBSE (Han et al., WMT 2021)
Copy Citation:
PDF:
https://aclanthology.org/2021.wmt-1.109.pdf
Software:
 2021.wmt-1.109.Software.zip
Code
 poethan/cushLEPOR
Data
WMT 2020