Retrieval Improvements Do Not Guarantee Better Answers: A Study of RAG for AI Policy QA

Fuente: arXiv
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Autores principales: Mathur, Saahil, Rittner, Ryan David, Thakur, Vedant Ajit, Schiff, Daniel Stuart, Islam, Tunazzina
Formato: Preprint
Publicado: 2026
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author Mathur, Saahil
Rittner, Ryan David
Thakur, Vedant Ajit
Schiff, Daniel Stuart
Islam, Tunazzina
author_facet Mathur, Saahil
Rittner, Ryan David
Thakur, Vedant Ajit
Schiff, Daniel Stuart
Islam, Tunazzina
contents Retrieval-augmented generation (RAG) systems are increasingly used to analyze complex policy documents, but achieving sufficient reliability for expert usage remains challenging in domains characterized by dense legal language and evolving, overlapping regulatory frameworks. We study the application of RAG to AI governance and policy analysis using the AI Governance and Regulatory Archive (AGORA) corpus, a curated collection of 947 AI policy documents. Our system combines a ColBERT-based retriever fine-tuned with contrastive learning and a generator aligned to human preferences using Direct Preference Optimization (DPO). We construct synthetic queries and collect pairwise preferences to adapt the system to the policy domain. Through experiments evaluating retrieval quality, answer relevance, and faithfulness, we find that domain-specific fine-tuning improves retrieval metrics but does not consistently improve end-to-end question answering performance. In some cases, stronger retrieval counterintuitively leads to more confident hallucinations when relevant documents are absent from the corpus. These results highlight a key concern for those building policy-focused RAG systems: improvements to individual components do not necessarily translate to more reliable answers. Our findings provide practical insights for designing grounded question-answering systems over dynamic regulatory corpora.
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id arxiv_https___arxiv_org_abs_2603_24580
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Retrieval Improvements Do Not Guarantee Better Answers: A Study of RAG for AI Policy QA
Mathur, Saahil
Rittner, Ryan David
Thakur, Vedant Ajit
Schiff, Daniel Stuart
Islam, Tunazzina
Computation and Language
Artificial Intelligence
Computers and Society
Information Retrieval
Machine Learning
Retrieval-augmented generation (RAG) systems are increasingly used to analyze complex policy documents, but achieving sufficient reliability for expert usage remains challenging in domains characterized by dense legal language and evolving, overlapping regulatory frameworks. We study the application of RAG to AI governance and policy analysis using the AI Governance and Regulatory Archive (AGORA) corpus, a curated collection of 947 AI policy documents. Our system combines a ColBERT-based retriever fine-tuned with contrastive learning and a generator aligned to human preferences using Direct Preference Optimization (DPO). We construct synthetic queries and collect pairwise preferences to adapt the system to the policy domain. Through experiments evaluating retrieval quality, answer relevance, and faithfulness, we find that domain-specific fine-tuning improves retrieval metrics but does not consistently improve end-to-end question answering performance. In some cases, stronger retrieval counterintuitively leads to more confident hallucinations when relevant documents are absent from the corpus. These results highlight a key concern for those building policy-focused RAG systems: improvements to individual components do not necessarily translate to more reliable answers. Our findings provide practical insights for designing grounded question-answering systems over dynamic regulatory corpora.
title Retrieval Improvements Do Not Guarantee Better Answers: A Study of RAG for AI Policy QA
topic Computation and Language
Artificial Intelligence
Computers and Society
Information Retrieval
Machine Learning
url https://arxiv.org/abs/2603.24580