Library Search Methods

A Boolean Operator is used to refine a search. Computers generally don’t do very well at guessing what you are asking for, so using the Boolean Operators AND, OR, NOT, and XOR will help you get just what you want in your search results.

Boolean Connectorscats AND dogs
cats OR dogs
cats NOT dogs
cats XOR dogs

  • AND means that both the words must be present in order for the record to be displayed.
  • OR means that either one or the other word or both words must be present.
  • NOT returns results that contain the first word, but drops any of those that contain the second word.
  • XOR includes results that contain one word or the other, but excludes those results that contain both.

Most of the time AND and OR will get you what you need.  NOT and XOR are less commonly used, but very helpful in the appropriate situation.  When trying to decide between AND and OR, think about whether the search will work if you only had one of these words or if both are necessary.  If you need both for the search to make sense, use AND.  If either term by itself is sufficient, use OR.

For example, in order to narrow down our search for music we could search for pop music. Because we have more than one word we are searching for we must use a Boolean Connector. If we search for pop or music we might find books about soda pop or classical music. That is because only one of the words needs to be found. If we search for pop and music, we would only find matches that have both words somewhere. It still might not be exactly we want but it will narrow down the search considerably.

By enclosing the search terms in quotes, many search engines will treat the words as a phrase, so “pop music” would return only results where that exact phrase appears.