AI More detail B · Official guidance Platform: AI

Hybrid Search

Hybrid search uses both exact-word search and meaning-based vector search for one question. It then joins or reranks both sets of results.

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You might call it Hybrid Search

See how it works

Original worked exampleHybrid Search

Another example

A question includes product code AX-410 and a symptom written in plain words. Exact-word search finds the code, vector search finds fixes with a similar meaning, and a written rule combines their ranks. Simply running two searches is not a complete hybrid design.

Main parts

  1. 01lexical results
  2. 02vector results
  3. 03fusion policy

Use it when

Use this term when a question needs both exact matches and results with a similar meaning.

Do not use it when

Do not add vector search when exact filters and word ranking already meet the measured need.

Name used in code

BM25 + vector kNN → rank fusion

Before you ship

Check the model and prompt versions, source data, versioned evaluation set, and measures. Verify links to evidence, tool permissions, privacy, common failures, decline-to-answer and fallback behavior, human review, monitoring, cost, speed, and rollback.

Request you can copy

Outcome: Use or evaluate Hybrid Search to make AI behavior measurable and tied to evidence. User context: A question includes product code AX-410 and a symptom written in plain words. Exact-word search finds the code, vector search finds fixes with a similar meaning, and a written rule combines their ranks. Simply running two searches is not a complete hybrid design. AI method or concept: Hybrid Search. Why it fits: Use this term when a question needs both exact matches and results with a similar meaning. Do not use it when: Do not add vector search when exact filters and word ranking already meet the measured need. AI requirements: Define the input and source evidence. Set model and tool permissions. Use versioned evaluation data and measures. Define failure, decline-to-answer, privacy, speed, and cost limits. Operational safeguards: Keep a clear trace and hide sensitive log data. Show users a safe fallback. Mark steps that need human review. Define how to roll back the model or prompt. Acceptance criteria: Record baseline and target measures on a versioned evaluation set. Test edge cases and hostile inputs. Verify fallback, monitoring, permissions, and rollback. Evidence and limits (evidence boundary): It is official for that source. Other platforms or teams may use the term in another way. Unknowns to confirm: Target task, model and version, evaluation owner, source data, risk limit, tool permissions, and production fallback.

Check this request

Review the current use of Hybrid Search. Definition: Hybrid search uses both exact-word search and meaning-based vector search for one question. It then joins or reranks both sets of results. Release checks: Check the model and prompt versions, source data, versioned evaluation set, and measures. Verify links to evidence, tool permissions, privacy, common failures, decline-to-answer and fallback behavior, human review, monitoring, cost, speed, and rollback. Before changing code, report the evidence you found, gaps, severity, and the smallest safe fix.

B
How official is this term?

Official guidance

The named platform, framework, project, or expert group has an official guide for this term.

It is official for that source. Other platforms or teams may use the term in another way.

Scope
Azure AI Search
Document status
stable
Checked on
2026-07-30

Evidence sources & scope

Authority source + Term reference · Microsoft · stable Hybrid search in Azure AI Search Scope: Azure AI Search lexical and vector result fusion Role here: Direct term reference Source covers: canonical name, definition, platform API, implementation, usage guidance

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