Conference Paper
Machine Learning

Astute RAG

Fei Wang, Xingchen Wan, Ruoxi Sun, Jiefeng Chen, Sercan Ö. Arik
October 9, 2024Annual Meeting of the Association for Computational Linguistics64 citations

64

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Influential Citations

Annual Meeting of the Association for Computational Linguistics

Venue

2024

Year

Abstract

Retrieval augmented generation (RAG), while effectively integrating external knowledge to address the inherent limitations of large language models (LLMs), can be hindered by imperfect retrieval that contain irrelevant, misleading, or even malicious information. Previous studies have rarely connected the behavior of RAG through joint analysis, particularly regarding error propagation coming from imperfect retrieval and potential conflicts between LLMs' internal knowledge and external sources. Through comprehensive and controlled analyses under realistic conditions, we find that imperfect retrieval augmentation is inevitable, common, and harmful. We identify the knowledge conflicts between LLM-internal and external knowledge from retrieval as a bottleneck to overcome imperfect retrieval in the post-retrieval stage of RAG. To address this, we propose Astute RAG, a novel RAG approach designed to be resilient to imperfect retrieval augmentation. It adaptively elicits essential information from LLMs' internal knowledge, iteratively consolidates internal and external knowledge with source-awareness, and finalizes the answer according to information reliability. Our experiments with Gemini and Claude demonstrate the superior performance of Astute RAG compared to previous robustness-enhanced RAG approaches. Specifically, Astute RAG is the only RAG method that achieves performance comparable to or even surpassing conventional use of LLMs under the worst-case scenario. Further analysis reveals the effectiveness of Astute RAG in resolving knowledge conflicts, thereby improving the trustworthiness of RAG.

Analysis

Why This Paper Matters

Retrieval augmented generation (RAG) has become a cornerstone technique for grounding large language models (LLMs) in external knowledge, yet its Achilles' heel remains imperfect retrieval. Real-world retrieval systems inevitably return irrelevant, misleading, or even malicious information, which can degrade LLM outputs. Prior work has largely treated retrieval and generation as separate stages, overlooking the critical interplay between an LLM's internal knowledge and externally retrieved content. This paper systematically demonstrates that imperfect retrieval is not just a nuisance but a fundamental bottleneck that propagates errors and creates knowledge conflicts. By connecting these dots, the authors highlight a pressing need for RAG systems that can gracefully handle retrieval failures.

Astute RAG directly addresses this gap by introducing a principled framework that adaptively leverages the LLM's own knowledge as a fallback and carefully reconciles conflicting information sources. This is particularly timely as LLMs are increasingly deployed in high-stakes domains like healthcare, finance, and legal reasoning, where reliability is paramount. The paper's emphasis on worst-case performance—a scenario often ignored in RAG evaluations—underscores its practical relevance.

Technical Contributions

  • Problem Formalization: The paper provides a controlled analysis framework to study error propagation and knowledge conflicts in RAG, establishing that imperfect retrieval is inevitable and harmful.
  • Adaptive Internal Knowledge Elicitation: Instead of blindly trusting retrieved passages, Astute RAG first elicits relevant internal knowledge from the LLM through targeted prompting, creating a baseline of what the model already knows.
  • Iterative Source-Aware Consolidation: The method iteratively compares internal and external knowledge, using source-awareness to weigh evidence. This allows the model to resolve contradictions by considering the reliability of each source.
  • Reliability-Based Answer Finalization: The final answer is generated based on the consolidated information, with explicit handling of cases where external information is deemed unreliable.
  • Empirical Validation on Multiple LLMs: The approach is tested on both Gemini and Claude, demonstrating generalizability across different model families.

Results

Astute RAG achieves superior performance compared to previous robustness-enhanced RAG approaches. Critically, it is the only RAG method that matches or surpasses the performance of conventional (non-RAG) LLM use under the worst-case scenario—a setting where retrieval is deliberately corrupted. This is a strong indicator of practical robustness. The paper also shows that Astute RAG effectively resolves knowledge conflicts, leading to more trustworthy outputs. While exact numerical metrics are not detailed in the abstract, the qualitative claims are backed by controlled experiments with Gemini and Claude.

Significance

This work has broad implications for the AI field. By demonstrating that knowledge conflicts are a key bottleneck, it shifts the focus from improving retrieval alone to designing post-retrieval strategies that can handle imperfect inputs. Astute RAG's source-aware iterative consolidation offers a blueprint for building more resilient RAG pipelines. For practitioners, this means deploying RAG in production with greater confidence, especially in domains where retrieval quality is unpredictable. The paper also opens avenues for future research on adaptive retrieval strategies and dynamic source weighting.