Once you determine your search terms (keywords), use Boolean operators (AND, OR, NOT) to combine or exclude search terms.
Using the keywords from the previous page (Heart Rate, Exercise), along with an additional keyword (Aerobics), we'll construct example searches using Boolean Operators with accompanying Venn Diagrams to help visualize what the search results will consist of.
PubMed search tips:
- Enter Boolean operators in uppercase characters.
- PubMed processes searches in a left-to-right sequence. Use parentheses to "nest" concepts that should be processed as a unit and then incorporated into the overall search.
AND retrieves results that include all the search terms.
OR retrieves results that include at least one of the search terms.
Using parentheses to "nest" concepts to be processed as a unit can make a substantial difference in the search results. Move your mouse over the Venn Diagram below to compare using parentheses versus not using parentheses.
NOT excludes the retrieval of terms from your search.