Counterfactual Debiasing for Fact Verification

Weizhi Xu, Qiang Liu, Shu Wu, Liang Wang


Abstract
Fact verification aims to automatically judge the veracity of a claim according to several pieces of evidence. Due to the manual construction of datasets, spurious correlations between claim patterns and its veracity (i.e., biases) inevitably exist. Recent studies show that models usually learn such biases instead of understanding the semantic relationship between the claim and evidence. Existing debiasing works can be roughly divided into data-augmentation-based and weight-regularization-based pipeline, where the former is inflexible and the latter relies on the uncertain output on the training stage. Unlike previous works, we propose a novel method from a counterfactual view, namely CLEVER, which is augmentation-free and mitigates biases on the inference stage. Specifically, we train a claim-evidence fusion model and a claim-only model independently. Then, we obtain the final prediction via subtracting output of the claim-only model from output of the claim-evidence fusion model, which counteracts biases in two outputs so that the unbiased part is highlighted. Comprehensive experiments on several datasets have demonstrated the effectiveness of CLEVER.
Anthology ID:
2023.acl-long.374
Volume:
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2023
Address:
Toronto, Canada
Editors:
Anna Rogers, Jordan Boyd-Graber, Naoaki Okazaki
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
6777–6789
Language:
URL:
https://aclanthology.org/2023.acl-long.374
DOI:
10.18653/v1/2023.acl-long.374
Bibkey:
Cite (ACL):
Weizhi Xu, Qiang Liu, Shu Wu, and Liang Wang. 2023. Counterfactual Debiasing for Fact Verification. In Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 6777–6789, Toronto, Canada. Association for Computational Linguistics.
Cite (Informal):
Counterfactual Debiasing for Fact Verification (Xu et al., ACL 2023)
Copy Citation:
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