# Fuzzy Search

Fuzzy search allows you to find words that are not spelled correctly. IDOL Server finds words that are spelled similarly to the search term. To run a fuzzy search, you use the `DREFUZZY` query operator in the Text parameter, followed by the search term in parentheses. For example: `DREFUZZY(elephent)`.

IDOL Server does not create extra index terms for fuzzy searches, so it does not increase the index size. However, fuzzy searches require a lot of extra processing, so they are slower than normal queries.

## Fuzzy Matching algorithm

The fuzzy algorithm uses a proprietary model to match correct documents even when spelling mistakes occurred in the query Text. It determines the closest matching words by analysis of common errors such as:

- the transposition of two letters.

- the use of incorrect vowels.

- pressing an adjacent key on the keyboard.

For example, a common error is putting one letter when it is supposed to be a double letter.

`WEDING` is a closer match to `WEDDING` than `WELDING`, even though in both cases legacy algorithms marked them all as one step apart.

Similarly, vowel errors are more common than consonants.

Someone spelling `BERMINGHAM` is more likely to mean `BIRMINGHAM` than `BERLINGHAM`, whereas legacy algorithms treat both as equally likely.

By default, the algorithm applies a dynamic threshold designed to give the most intuitive determination of whether a term matches or not. You can also give the operator an explicit distance to arrive at more controllable results.

    DREFUZZY4(elephent)

Related Topics

- Soundex Search

- Query Syntax

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