- https://arxiv.org/html/2402.03367v2
- Source: arxiv
TL;DR
RAG-Fusion generates multiple semantically diverse query variants via an LLM and merges their ranked retrieval lists using Reciprocal Rank Fusion, producing more robust context than single-query RAG.
Summary
RAG-Fusion extends standard RAG by generating multiple semantically diverse query variants from the original user query using an LLM. Each variant retrieves its own ranked document list; the lists are then merged using Reciprocal Rank Fusion (RRF), which promotes documents that rank consistently across multiple perspectives. The fused ranking surfaces more comprehensive and robust context than single-query retrieval, reducing sensitivity to query phrasing and improving downstream QA accuracy.
Key contributions
- Proposes RAG-Fusion, combining LLM-based multi-query generation with Reciprocal Rank Fusion to improve retrieval robustness.
- Demonstrates that RRF is a parameter-free rank aggregation method that straightforwardly improves any existing retrieval pipeline.
- Shows that query diversification reduces brittleness of embedding-based retrieval without requiring thesauri or domain vocabulary.
- Establishes that multi-query retrieval outperforms single-query RAG on QA benchmarks with minimal additional latency.
When to cite
- When implementing multi-query retrieval strategies to reduce sensitivity to query phrasing in RAG systems.
- When applying Reciprocal Rank Fusion as a parameter-free method to aggregate ranked retrieval lists.
- When discussing query expansion techniques that use an LLM rather than domain-specific vocabulary resources.
- When evaluating the latency-quality tradeoff of multi-query retrieval approaches before deployment.
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