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Retrieval & knowledge

Hybrid search

Also called: keyword plus semantic, BM25 and vectors, lexical and dense

DEFINITION

Combining classic keyword search with meaning-based vector search, then merging the results — so retrieval catches both the exact term a keyword search nails and the paraphrase only semantic search can find.

WHY IT MATTERS

Each method has a blind spot: vector search can miss an exact product code, error string, or name; keyword search misses anything worded differently. Hybrid search is the common fix for 'it couldn't find the one document I knew was there', and often lifts retrieval quality more than swapping the model.

COMMONLY CONFUSED WITH

Pure semantic search. Embeddings alone quietly drop exact identifiers; hybrid keeps a keyword safety net underneath the meaning match.