On the Evaluation Metrics for Paraphrase Generation

Lingfeng Shen, Lemao Liu, Haiyun Jiang, Shuming Shi


Abstract
In this paper we revisit automatic metrics for paraphrase evaluation and obtain two findings that disobey conventional wisdom: (1) Reference-free metrics achieve better performance than their reference-based counterparts. (2) Most commonly used metrics do not align well with human annotation.Underlying reasons behind the above findings are explored through additional experiments and in-depth analyses.Based on the experiments and analyses, we propose ParaScore, a new evaluation metric for paraphrase generation. It possesses the merits of reference-based and reference-free metrics and explicitly models lexical divergence. Based on our analysis and improvements, our proposed reference-based outperforms than reference-free metrics.Experimental results demonstrate that ParaScore significantly outperforms existing metrics.
Anthology ID:
2022.emnlp-main.208
Volume:
Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing
Month:
December
Year:
2022
Address:
Abu Dhabi, United Arab Emirates
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
3178–3190
Language:
URL:
https://aclanthology.org/2022.emnlp-main.208
DOI:
Bibkey:
Cite (ACL):
Lingfeng Shen, Lemao Liu, Haiyun Jiang, and Shuming Shi. 2022. On the Evaluation Metrics for Paraphrase Generation. In Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing, pages 3178–3190, Abu Dhabi, United Arab Emirates. Association for Computational Linguistics.
Cite (Informal):
On the Evaluation Metrics for Paraphrase Generation (Shen et al., EMNLP 2022)
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PDF:
https://preview.aclanthology.org/ingestion-script-update/2022.emnlp-main.208.pdf