Applying spelling correction, thesaurus, and stemming with the Phrase module

Describes available functions with query expansion enabled.

Applying spelling correction, thesaurus, and stemming adjustments to the original phrase is generically known as query expansion. With query expansion enabled, the Phrase module ranks results that match a phrase's expanded forms in the same stratum as results that match the original phrase. Consider the following example:

A thesaurus entry exists that expands "US" to "United States."
The user queries for "US government."

The query, "US government," is expanded to "United States government" for matching purposes, but the Phrase module gives a score of two to any results matching "United States government" because the original, unexpanded version of the query, "US government," only had two terms.