Glossary · Retrieval & generation
Reciprocal Rank Fusion (RRF)
A rank-fusion method that combines several result lists by summing contributions that decrease with each item's rank in each list.
Why it matters
It can merge lexical, dense, or multi-query rankings without assuming their raw scores share the same scale.
In practice
Retrieve independent candidate lists, deduplicate by stable document identity, apply one versioned fusion constant, and evaluate against each individual retriever.
Common confusion
RRF combines ranks, not embeddings or relevance scores, and it cannot recover an item absent from every input list.
Related terms
Sources
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