Boolean Searching

The Rules

Boolean searching lets you specify some words as alternatives to the Keyword you are looking for. Boolean Searching also lets you define some words that should not be in the document. The three Boolean operators are AND, OR, and NOT.

As an example, "bodkin AND uncle AND Denmark" might select the play Hamlet, while "bodkin OR uncle" would find other plays that have uncles in them. Finally the search for "bodkin NOT "uncle" would find other plays that only have "bodkin" and where the word "uncle does not occur.

Boolean searching seems simple, but people often misuse it. Statistical analysis shows that:

AND is too powerful at reducing matches and will take away too choices that would have met your criteria, if it is used incorrectly
most people cannot properly pose a query involving NOT
OR is relatively safe to use

Another problem with using Boolean logic is that it can be relatively complicated.

Return to Table of Contents Page

This file prepared and presented as an aid to help students understand the web. Send questions or comments to Royce Shook

Hosted by www.Geocities.ws