Information Literacy Learning Guides

Key Concepts & Practice

Boolean Searching

Quick Guide to Boolean Searching

Boolean searching is method of combining two or more search terms to increase (BROADEN) or restrict (NARROW) the amount found by a search in a catalogue, database or search engine. Boolean searching allows you to combine search terms using the three Boolean operators AND, OR, NOT. To execute a Boolean search, enter the required terms separated by the Boolean operators you wish to use.

Most search engines include an "advanced search" or "power search" mode that allows you to use these search strategies. Also, always check to see if there is a 'search tip' guide to help you use that specific search engine more effectively.
 

AND	Rock AND Roll	And = All:     Both phrases must appear in the results. Using "and" narrows your search, as it restricts the documents retrieved to only those that contain your search terms.     results:   music
OR	Rock OR Roll	Or = Any:     One or the other term must appear in the results. When you put "or" between your terms, you broaden your search    results:   igneous rocks, gemstones, crescent rolls, music
NOT	Rock NOT Roll	Not = Not:     When you put "not" in front of a search term, you exclude it. This is another way to narrow your search.      results:   igneous rocks, gemstones