Answered By: Jennifer Stidham Last Updated: Mar 03, 2016 Views: 260
In library terms, a Boolean operator is a word that can be used to broaden, narrow, or ignore specific terms in search results. There are three (3) operators used. These operators are AND, OR, and NOT.
Using AND between terms will narrow your search results, showing fewer results than either word individually. The results will only be documents that contain all terms. For example, dog AND cat would return results that contain only both words.
Using OR between terms will broaden your search results, showing more results than either word individually. For example, dog OR cat would return results that contain at least one of those words.
Using NOT before a term will narrow your search results, excluding the terms after NOT. For example, mexico NOT new would filter out anything regarding New Mexico, but might also filter out results that use the word new elsewhere in the document.