Veri-R1: Toward Precise and Faithful Claim Verification via Online Reinforcement Learning
Qi He, Cheng Qian, Xiusi Chen, Bingxiang He, Yi R. Fung, Heng Ji
Abstract
Claim verification with large language models (LLMs) has recently attracted growing attention, due to their strong reasoning capabilities and transparent verification processes compared to traditional answer-only judgments. However, existing approaches to online claim verification, which requires iterative evidence retrieval and reasoning, still mainly rely on prompt engineering or pre-designed reasoning workflows, without unified training to improve necessary skills. Therefore, we introduce Veri-R1, an online reinforcement learning (RL) framework that enables an LLM to interact with a search engine and to receive reward signals that explicitly shape its planning, retrieval, and reasoning behaviors. The dynamic interaction between models and retrieval systems more accurately reflects real-world verification scenarios and fosters comprehensive verification skills. Empirical results show that Veri-R1 improves joint accuracy by up to 30% and doubles evidence score, often surpassing its larger-scale model counterparts. Ablation studies further reveal the impact of reward components, and the link between output logits and label accuracy. Our results highlight the effectiveness of online RL for precise and faithful claim verification, and provide a foundation for future research.- Anthology ID:
- 2026.findings-acl.1019
- Volume:
- Findings of the Association for Computational Linguistics: ACL 2026
- Month:
- July
- Year:
- 2026
- Address:
- San Diego, California, United States
- Editors:
- Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
- Venue:
- Findings
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 20372–20391
- Language:
- URL:
- https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1019/
- DOI:
- Cite (ACL):
- Qi He, Cheng Qian, Xiusi Chen, Bingxiang He, Yi R. Fung, and Heng Ji. 2026. Veri-R1: Toward Precise and Faithful Claim Verification via Online Reinforcement Learning. In Findings of the Association for Computational Linguistics: ACL 2026, pages 20372–20391, San Diego, California, United States. Association for Computational Linguistics.
- Cite (Informal):
- Veri-R1: Toward Precise and Faithful Claim Verification via Online Reinforcement Learning (He et al., Findings 2026)
- PDF:
- https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1019.pdf