Using AND, OR, and NOT to Refine your Keyword Search

In a Boolean search, keywords are combined by the operators AND, OR and NOT to narrow or broaden the search.

Using Pippi Longstocking and Ikea, this Venn diagram helps to visualize the meaning of AND and OR.

Image by Jenny Makofsky, Have You Seen the Dog Lately? "She's a Bad Mamma-Jamma" issue, 2001
(Barnard call number: Zines M234h Pajamas). Published by permission of Serena Makofsky.

AND
The operator AND narrows the search by instructing the search engine to search for all the records containing the first keyword, then for all the records containing the second keyword, and show only those records that contain both. 

The middle portion represents AND, or terms that could be used to describe both Pippi AND Ikea.

OR
The operator OR broadens the search to include records containing either keyword, or both.
The OR search is particularly useful when there are several common synonyms for a concept, or variant spellings of a word.

The portions on either side of the image, represent descriptors of either Pippi OR Ikea.

NOT
Combining search terms with the NOT operator narrows the search by excluding unwanted terms.

Jenna Freedman, Coordinator of Reference Services and Zine Librarian
Adapted from Lois Coleman's more traditional version.
Last updated 08/19/2009