EGR-FV: Evidence-Grounded Remixing for Debiased Fact Verification via Counterfactual Necessity-Guided Training

Jun Yang, Dandan Song, Zhijing Wu, Yuhang Tian, Huipeng Ma, Chenhao Li, Yizhou Jin, Guangyuan Feng, Xudong Li


Abstract
Automatic fact verification (FV) predicts the veracity of a claim against retrieved evidence, yet modern verifiers often behave as shortcut-driven verifiers, predicting from surface regularities in the claim rather than the factual content of the evidence. Existing debiasing methods over-correct this by uniformly enforcing evidence reliance on every sample, thereby suppressing the valid information already carried by the claim itself. We propose Evidence-Grounded Remixing for Fact Verification (EGR-FV), which estimates a per-sample evidence necessity score by contrasting claim-with-evidence and claim-only predictions, and uses it to remix training batches so that debiasing is adapted to each sample’s actual reliance on evidence. On FEVER, PolitiHop, and HOVER together with their symmetric counterparts, EGR-FV achieves state-of-the-art accuracy and robustness, validating the effectiveness of EGR-FV.
Anthology ID:
2026.emnlp-main.813
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
18931–18945
Language:
URL:
https://aclanthology.org/2026.emnlp-main.813/
DOI:
Bibkey:
Cite (ACL):
Jun Yang, Dandan Song, Zhijing Wu, Yuhang Tian, Huipeng Ma, Chenhao Li, Yizhou Jin, Guangyuan Feng, and Xudong Li. 2026. EGR-FV: Evidence-Grounded Remixing for Debiased Fact Verification via Counterfactual Necessity-Guided Training. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 18931–18945, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
EGR-FV: Evidence-Grounded Remixing for Debiased Fact Verification via Counterfactual Necessity-Guided Training (Yang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.813.pdf