Boolean Operators are used to connect and define the relationship between your search terms. When searching electronic databases, you can use Boolean operators to either narrow or broaden your record sets. The three Boolean operators are AND, OR and NOT.
Use AND to narrow your search: all of your search terms will present in the retrieved records.
The oval in the middle of the Venn diagram below represents the result set for this search. It is the combination of these two search terms.
Example: Online courses AND academic performance
Use OR to broaden your search by connecting two or more synonyms.
Example: online courses OR Web-based instruction OR distance education
The database retrieves all the unique records containing one term, the other, or both.
Use NOT to exclude term(s) from your search results.
Example: higher education NOT community colleges