Boolean operators are connectors used to show a relationship between keywords. The three Boolean operators used in research databases include: AND, OR, NOT
AND - use this operator between keywords to narrow your search and reduce the size of your results
Ex. Zika AND Florida - this search tells the database that you only want articles that include Zika AND Florida within them.
OR - use this operator between keywords to broaden your search and increase the size of your results
Ex. Iraq OR Syria - this search tells the database that you want any articles that contain either Iraq OR Syria; only one of the keywords has to be present in the article to be part of your results
NOT - use this operator to exclude a keyword from your search
Ex. obesity NOT childhood - this search tells the database that you want articles on obesity as long as they exclude reference to childhood
Need more examples? See this short video from Stewart Library at Weber State University: Boolean Operators
Most research databases allow universal shortcuts in the basic search box. These universal shortcuts include:
Exact Phrase Searching - use quotation marks to retrieve the phrase typed within
Ex. "weapons of mass destruction" will look for that phrase in articles, whereas weapons of mass destruction will also retrieve any articles on weapons and mass and destruction as individual keywords
Nested Searching - helps a database search more efficiently for two keywords that are similar conceptually and connected in the keyword search with a Boolean operator. Use parentheses around these two keywords to do nested searching.
Ex. "weapons of mass destruction" AND (Iraq or Syria) - parentheses help the database understand the relationship between the keywords within for organizing the search
Truncation - broadens the search by instructing the database to include variations of a keyword by shortening the keyword with an asterisk
Ex. psyc* will find: psychology, psychologist, psychological, psychiatry, psychiatrist, psychiatric, psychosis, psychotic, etc.
psychol* will find: psychology, psychologist, psychological, etc.
Research databases usually default to basic search boxes, but will include links to Advanced Search features that will prompt for Boolean operators and other ways to limit the search.