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Eastern Washington University Libraries

College Assistance Migrant Program (CAMP) - Library Resources Guide

Creating a Search Strategy with Boolean Operators

Steps to conduct an effective search:

1. Construct a well-formulated research question about the topic you are interested.
2. Identify main elements of the question and develop the keywords that capture those key concepts.
3. Select synonyms that represent the same key concepts in your question to find studies/articles that just use different vocabulary to mean the exact same thing.
4. Build an effective search query/statement using Boolean operators (AND, OR, NOT) when appropriate.

Boolean Logic

Why use Boolean operators?
(a). To focus a search, particularly when your topic contains multiple search terms.
(b). To connect search terms to find exactly what you're looking for (e.g. use AND to combine PICO components and OR to combine related terms within a component).

Boolean logic defines logical relationships between terms in a search. The Boolean search operators are used to create a very broad or very narrow search.

AND is used to narrow the search results The search results contain all of the search terms.
OR is used to broaden the search results. The search results contain at least one of the search terms.
NOT is used to exclude terms from your search. The search results does not contain any of the terms that follow it.

Note: Parentheses ( ) can be used to group together keywords. Keywords and Boolean operators within parentheses will be searched first, followed by other keywords outside parentheses. In addition, if you search for a phrase rather than just a single word, you can group the words together with double quotation marks (i.e. "global warming").

Research question: What is the connection between smoking and depression among teenagers?
Major concepts in the question: smoking, depression, teenagers.
Search statement: (smoking OR cigarettes) AND (depression OR mental health) AND (teenagers OR youth)

In sum, (1) narrow your search using AND; (2) expand your search using OR; and (3) narrow your results using NOT.

View a Search Strategy Graphic