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Systematic Reviews

Using Boolean Logic

In general, it is recommended that you work with a librarian to help you design comprehensive search strategies across a variety of databases. Writing a successful search strategy takes an intimate knowledge of bibliographic databases. 

Using boolean logic is an important component of writing a search strategy.  This can be tricky, because each database operates a little differently.  However, some general rules of thumb are that:

  • "AND" narrows the search
  • "OR" broadens the search
  • "NOT" excludes terms
  • "*" finds all forms of a particular word
  • parentheses ensure all terms will be searched together as a set
  • quotations around a phrase searches that exact phrase

And requires the database to use both terms such as requiring articles about both puppies AND kittens. Or tells the database you want to include articles about either term - either puppies OR kittens. Not tells the database to not include a term - puppies NOT kittens.

For more help view our guide on boolean operators. 

Get Help

Librarians can help you learn how to search for existing information on your topic. Finding existing reviews on your topic will inform the development of your research question, identify gaps, and confirm that you are not duplicating the efforts of previous reviews. Contact your liaison librarian to learn more about developing a research question.