The Missing Parts: Augmenting Fact Verification with Half Truth Detection

Yixuan Tang, Jincheng Wang, Anthony Kum Hoe Tung


Abstract
Fact verification systems typically assess whether a claim is supported by retrieved evidence, assuming that truthfulness depends solely on what is stated. However, many real-world claims are half-truths, factually correct yet misleading due to the omission of critical context. Existing models struggle with such cases, as they are not designed to reason about omitted information. We introduce the task of half-truth detection, and propose PolitiFact-Hidden, a new benchmark with 15k political claims annotated with sentence-level evidence alignment and inferred claim intent. To address this challenge, we present TRACER, a modular re-assessment framework that identifies omission-based misinformation by aligning evidence, inferring implied intent, and estimating the causal impact of hidden content. TRACER can be integrated into existing fact-checking pipelines and consistently improves performance across multiple strong baselines. Notably, it boosts Half-True classification F1 by up to 16 points, highlighting the importance of modeling omissions for trustworthy fact verification. The benchmark and code are available via https://github.com/tangyixuan/TRACER.
Anthology ID:
2025.emnlp-main.1724
Volume:
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
EMNLP
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Publisher:
Association for Computational Linguistics
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Pages:
33967–33984
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URL:
https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-main.1724/
DOI:
Bibkey:
Cite (ACL):
Yixuan Tang, Jincheng Wang, and Anthony Kum Hoe Tung. 2025. The Missing Parts: Augmenting Fact Verification with Half Truth Detection. In Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing, pages 33967–33984, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
The Missing Parts: Augmenting Fact Verification with Half Truth Detection (Tang et al., EMNLP 2025)
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https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-main.1724.pdf
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