Hybrid Retrieval
Also: hybrid search · dense + sparse retrieval
Combines semantic (dense vector) and keyword (sparse/BM25) search so you catch both meaning and exact terms.
Why CCAR-P tests this
It is the go-to remedy when pure vector search fails on names, codes, and jargon, and P3 tests whether you know why to blend the two.
Hybrid retrieval runs dense semantic search (embeddings, good at paraphrase and conceptual match) alongside sparse lexical search (BM25/keyword, good at exact tokens — product SKUs, error codes, acronyms, names) and fuses the results. A common fusion method is Reciprocal Rank Fusion (RRF), which merges ranked lists without needing comparable raw scores.
Each mode covers the other's blind spot. Pure vector search can miss an exact identifier that shares no semantic neighborhood; pure keyword search misses synonyms and intent. Blending them raises recall across query types, which is why hybrid is a strong default for enterprise corpora full of domain-specific terms.
Hybrid is a first-stage technique that produces a better candidate set; it pairs naturally with reranking as the precision second stage. Boosting recall first and refining order second is the canonical high-quality retrieval stack.
Exam trap
Hybrid retrieval improves recall of the candidate set — it does not by itself put the single best chunk on top; that ordering job belongs to reranking.
Commonly confused with
Related concepts
Independent, unofficial study material from Claude Cert Prep. Not affiliated with Anthropic.