Now you’re ready to combine your keywords. The words and symbols used to combine them are called Boolean Operators. There are only a handful that you need to learn. Using them in combination will enable you to get the most relevant results and filter out the irrelevant results.
|Operator||Example||How It Works|
|” “||“siamese cats”||Searches a phrase. Tells the database to search for the keywords together in that order.|
|AND||cats AND dogs||Tells the database to find search results that have both keywords. Fewer, more specific search results.|
|OR||cats OR dogscats OR felines||Tells the database to find search results that contain either keyword.
Increases number of search results.
|NOT||cats NOT siamese||Used to exclude certain keywords. Fewer, more specific search results.|
|*, ! or ?||veterinar*||Wildcard symbol is used to get different word endings.
Different databases use different symbols.
Explore the Boolean Machine by Rockwell Schrock. It explains AND, OR and NOT in a visual, intuitive way.
You can use those few operators to combine multiple concepts, each with its own set of keywords. To do that, you need to use parentheses.
Click through the mini-slideshow to learn how to combine multiple sets of keywords using parentheses. If the text is too small to read, click the menu icon in the lower left corner of the box and select “view full screen.”
For a fun, visual explanation, see the Advanced Boolean Searching demonstration from Colorado State University Libraries.
Practice these search techniques using the Search Query Magnets game from the University of Washington Libraries. Try several queries and compare your solution to the explanation they provide.
One more thing – you can also use these techniques in Google and Google Scholar!