Answered By: Lynn VanLeer
Last Updated: Mar 14, 2019     Views: 8217

Boolean operators are words that connect search terms (keywords) to create a logical phrase that a database can understand. They allow you to create a complex search that could include multiple concepts and alternative keywords.

Explanation of Boolean operators AND, OR, and NOT


What it Does

          How to use


Finds items that use both keywords.

adult learning


online courses


          Finds items that use either of the keywords.

adult learners


adult students



Excludes articles that use the keyword.


NOT masters programs     


Most library databases are designed to work with the above Boolean operators. Search engines, such as Google, also use Boolean operators to create complex searches.


Tips for using Boolean operators in Library databases:

  • Include one concept per search box.

  • Use the AND operator between search boxes. Caution: Connecting too many concepts with AND will make your search very narrow or could give you no results.

  • Use the OR operator with alternative terms inside a single search box. Caution: Using OR between search boxes will look for either concept in both boxes and could make your results very large.

  • Use the NOT operator by selecting it in front of the final search box to exclude the keyword in that search box. Caution: Use only when truly needed to remove a concept from your search, because it could also remove useful results.



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