Decoder. plain-English AI glossary

Query Expansion

▲ Rising

Also called Query Enrichment

Quietly adding synonyms and related terms to a search so it catches documents worded differently.

Think of it like

Asking for "soda" and having the waiter also check for "pop" and "fizzy drink".

Example

A search for "laptop won’t charge" is expanded with "battery", "power adapter", "not powering on" to widen the net.

How it actually works

Query expansion augments the original query with extra terms — from synonyms, related searches, or an LLM — to improve recall when the corpus uses different vocabulary. It helps sparse methods most, since those depend on exact overlap. The risk is drift: add too many loosely related terms and you dredge up irrelevant results, hurting precision.

For product teams

Catches answers users would otherwise miss due to wording, at some risk of noisier results.

For engineers

Augment the query with synonyms/related terms (thesaurus, PRF, or LLM-generated); raises recall, can dent precision.

Related

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