Beyond Black-Box Interventions: Latent Probing for Faithful Retrieval-Augmented Generation

Fuente: arXiv
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Main Authors: Gao, Linfeng, Zhang, Qinggang, Bi, Baolong, Zeng, Bo, Yuan, Zheng, Chen, Zerui, Wei, Zhimin, Liu, Shenghua, Xu, Linlong, Wang, Longyue, Luo, Weihua, Su, Jinsong
Format: Preprint
Published: 2025
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author Gao, Linfeng
Zhang, Qinggang
Bi, Baolong
Zeng, Bo
Yuan, Zheng
Chen, Zerui
Wei, Zhimin
Liu, Shenghua
Xu, Linlong
Wang, Longyue
Luo, Weihua
Su, Jinsong
author_facet Gao, Linfeng
Zhang, Qinggang
Bi, Baolong
Zeng, Bo
Yuan, Zheng
Chen, Zerui
Wei, Zhimin
Liu, Shenghua
Xu, Linlong
Wang, Longyue
Luo, Weihua
Su, Jinsong
contents Retrieval-Augmented Generation (RAG) systems often fail to maintain contextual faithfulness, generating responses that conflict with the provided context or fail to fully leverage the provided evidence. Existing methods attempt to improve faithfulness through external interventions, such as specialized prompting, decoding-based calibration, or preference optimization. However, since these approaches treat the LLM as a black box, they lack a reliable mechanism to assess when and why knowledge conflicts occur. Consequently, they tend to be brittle, data-intensive, and agnostic to the model's internal reasoning process. In this paper, we move beyond black-box interventions to analyze the model's internal reasoning process. We discover that conflicting and aligned knowledge states are linearly separable in the model's latent space, and contextual noise systematically increases the entropy of these representations. Based on these findings, we propose ProbeRAG, a novel framework for faithful RAG that operates in three stages: (i) fine-grained knowledge pruning to filter irrelevant context, (ii) latent conflict probing to identify hard conflicts in the model's latent space, and (iii) conflict-aware attention to modulate attention heads toward faithful context integration. Extensive experiments demonstrate that ProbeRAG substantially improves both accuracy and contextual faithfulness. The related resources are available at https://github.com/LinfengGao/ProbeRAG.
format Preprint
id arxiv_https___arxiv_org_abs_2510_12460
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Beyond Black-Box Interventions: Latent Probing for Faithful Retrieval-Augmented Generation
Gao, Linfeng
Zhang, Qinggang
Bi, Baolong
Zeng, Bo
Yuan, Zheng
Chen, Zerui
Wei, Zhimin
Liu, Shenghua
Xu, Linlong
Wang, Longyue
Luo, Weihua
Su, Jinsong
Computation and Language
Retrieval-Augmented Generation (RAG) systems often fail to maintain contextual faithfulness, generating responses that conflict with the provided context or fail to fully leverage the provided evidence. Existing methods attempt to improve faithfulness through external interventions, such as specialized prompting, decoding-based calibration, or preference optimization. However, since these approaches treat the LLM as a black box, they lack a reliable mechanism to assess when and why knowledge conflicts occur. Consequently, they tend to be brittle, data-intensive, and agnostic to the model's internal reasoning process. In this paper, we move beyond black-box interventions to analyze the model's internal reasoning process. We discover that conflicting and aligned knowledge states are linearly separable in the model's latent space, and contextual noise systematically increases the entropy of these representations. Based on these findings, we propose ProbeRAG, a novel framework for faithful RAG that operates in three stages: (i) fine-grained knowledge pruning to filter irrelevant context, (ii) latent conflict probing to identify hard conflicts in the model's latent space, and (iii) conflict-aware attention to modulate attention heads toward faithful context integration. Extensive experiments demonstrate that ProbeRAG substantially improves both accuracy and contextual faithfulness. The related resources are available at https://github.com/LinfengGao/ProbeRAG.
title Beyond Black-Box Interventions: Latent Probing for Faithful Retrieval-Augmented Generation
topic Computation and Language
url https://arxiv.org/abs/2510.12460