Efficient Prior-Guided Reasoning for Robust Retrieval-Augmented Generation under Conflicts

Xiaowei Yuan, Ziyang Huang, Zhao Yang, Yequan Wang, Jun Zhao, Kang Liu


Abstract
Retrieval-Augmented Generation (RAG) has become a standard paradigm for grounding Large Language Models (LLMs) with external knowledge. However, RAG performance often degrades substantially when faced with noisy, outdated, or conflicting retrieved information. In this work, we empirically demonstrate that Prior-Guided Reasoning—a strategy that explicitly elicits the model’s parametric knowledge as prior information to guide reasoning on retrieved documents—effectively mitigates the impact of external conflicts. Building on this, we propose BrPr (Bernoulli-gated reinforcement learning for Prior-Guided reasoning), a framework that achieves robust performance across varying degrees of external inconsistency. Furthermore, by employing a Bernoulli-gated dropout mechanism during training, BrPr distills the prior-driven reasoning capability into the model parameters, enabling efficient latent reasoning without explicit prior generation. The experimental results demonstrate that BrPr consistently exhibits superior robustness to external conflicts and noise.
Anthology ID:
2026.acl-long.1013
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
ACL
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Publisher:
Association for Computational Linguistics
Note:
Pages:
22149–22164
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URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.1013/
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Bibkey:
Cite (ACL):
Xiaowei Yuan, Ziyang Huang, Zhao Yang, Yequan Wang, Jun Zhao, and Kang Liu. 2026. Efficient Prior-Guided Reasoning for Robust Retrieval-Augmented Generation under Conflicts. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 22149–22164, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Efficient Prior-Guided Reasoning for Robust Retrieval-Augmented Generation under Conflicts (Yuan et al., ACL 2026)
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https://preview.aclanthology.org/ingest-acl/2026.acl-long.1013.pdf
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