query expansion

information science Adding search terms to a user's

search. Query expansion is the process of a search engine

adding search terms to a user's weighted search. The

intent is to improve precision and/or recall. The

additional terms may be taken from a thesaurus. For example

a search for "car" may be expanded to: car cars auto autos

automobile automobiles.

The additional terms may also be taken from documents

that the user has specified as being relevant; this is the

basis for the "more like this" feature of some search engines.

The extra terms can have positive or negative weights.

(1999-08-27)