Cluster-based Adaptive Retrieval: Dynamic Context Selection for RAG Applications

Fuente: arXiv
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Main Authors: Xu, Yifan, Gupta, Vipul, Aggarwal, Rohit, Mahadevan, Varsha, Krishnamachari, Bhaskar
Format: Preprint
Published: 2025
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author Xu, Yifan
Gupta, Vipul
Aggarwal, Rohit
Mahadevan, Varsha
Krishnamachari, Bhaskar
author_facet Xu, Yifan
Gupta, Vipul
Aggarwal, Rohit
Mahadevan, Varsha
Krishnamachari, Bhaskar
contents Retrieval-Augmented Generation (RAG) enhances large language models (LLMs) by pulling in external material, document, code, manuals, from vast and ever-growing corpora, to effectively answer user queries. The effectiveness of RAG depends significantly on aligning the number of retrieved documents with query characteristics: narrowly focused queries typically require fewer, highly relevant documents, whereas broader or ambiguous queries benefit from retrieving more extensive supporting information. However, the common static top-k retrieval approach fails to adapt to this variability, resulting in either insufficient context from too few documents or redundant information from too many. Motivated by these challenges, we introduce Cluster-based Adaptive Retrieval (CAR), an algorithm that dynamically determines the optimal number of documents by analyzing the clustering patterns of ordered query-document similarity distances. CAR detects the transition point within similarity distances, where tightly clustered, highly relevant documents shift toward less pertinent candidates, establishing an adaptive cut-off that scales with query complexity. On Coinbase's CDP corpus and the public MultiHop-RAG benchmark, CAR consistently picks the optimal retrieval depth and achieves the highest TES score, outperforming every fixed top-k baseline. In downstream RAG evaluations, CAR cuts LLM token usage by 60%, trims end-to-end latency by 22%, and reduces hallucinations by 10% while fully preserving answer relevance. Since integrating CAR into Coinbase's virtual assistant, we've seen user engagement jump by 200%.
format Preprint
id arxiv_https___arxiv_org_abs_2511_14769
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Cluster-based Adaptive Retrieval: Dynamic Context Selection for RAG Applications
Xu, Yifan
Gupta, Vipul
Aggarwal, Rohit
Mahadevan, Varsha
Krishnamachari, Bhaskar
Information Retrieval
Artificial Intelligence
Computation and Language
Machine Learning
Retrieval-Augmented Generation (RAG) enhances large language models (LLMs) by pulling in external material, document, code, manuals, from vast and ever-growing corpora, to effectively answer user queries. The effectiveness of RAG depends significantly on aligning the number of retrieved documents with query characteristics: narrowly focused queries typically require fewer, highly relevant documents, whereas broader or ambiguous queries benefit from retrieving more extensive supporting information. However, the common static top-k retrieval approach fails to adapt to this variability, resulting in either insufficient context from too few documents or redundant information from too many. Motivated by these challenges, we introduce Cluster-based Adaptive Retrieval (CAR), an algorithm that dynamically determines the optimal number of documents by analyzing the clustering patterns of ordered query-document similarity distances. CAR detects the transition point within similarity distances, where tightly clustered, highly relevant documents shift toward less pertinent candidates, establishing an adaptive cut-off that scales with query complexity. On Coinbase's CDP corpus and the public MultiHop-RAG benchmark, CAR consistently picks the optimal retrieval depth and achieves the highest TES score, outperforming every fixed top-k baseline. In downstream RAG evaluations, CAR cuts LLM token usage by 60%, trims end-to-end latency by 22%, and reduces hallucinations by 10% while fully preserving answer relevance. Since integrating CAR into Coinbase's virtual assistant, we've seen user engagement jump by 200%.
title Cluster-based Adaptive Retrieval: Dynamic Context Selection for RAG Applications
topic Information Retrieval
Artificial Intelligence
Computation and Language
Machine Learning
url https://arxiv.org/abs/2511.14769