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How to Search using Boolean Logic

Boolean Logic is a way of narrowing or expanding a database search by linking search terms with the connectors AND, OR, and NOT.

Boolean Logic - AND

 

 AND

  • narrows a search by linking two or more terms
  • Use the connector AND to retrieve items that must have BOTH terms
  • AND is used to combine different ideas or concepts
  • only items represented by the shaded area are retrieved.

 

 

 

 OR

  • broadens a search by linking two or more terms
  • use the connector OR to retrieve items that may have EITHER term
  • OR is used to combine synonyms or related terms
  • Items represented by the shaded area are retrieved.

 

 

NOT

  • narrows a search by excluding items containing a second search term
  • use the connector NOT to find items that have the first term but not the second
  • in the example, all items with the term cats will be retrieved except those also containing the word dogs
  • only items represented by the shaded area are retrieved
  • use NOT with caution; you may exclude relevant items