Boolean operators (AND, OR, NOT) serve to either narrow or expand your search:
- AND narrows a search by finding the subset of articles that contain both search terms you want (Homeless* AND Veteran*);
- OR expands a search by including synonyms or related terms (e.g. Homeless* OR Shelter*);
- NOT narrows your search by eliminating articles that contain a specific term you do not want (neglect NOT abuse).
Boolean operators are words (or, and, not) used to connect search terms to expand (or) or narrow (and, not) a search within a database to locate relevant information. Boolean operators are also called logical operators or connectors.
It is helpful to diagram the effects of these operators:
women or females
|Or retrieves records that contain any of the search terms. It expands the search. Therefore, use "or" in between terms that have the same meaning (synonyms) or equal value to the search.|
women and media
|And retrieves records that contain all of the search terms. It narrows or limits the search. Therefore, use "and" in between terms that are required to make the search specific.|
image not weight
|Not eliminates records that contain a search term. It narrows or limits the search. Therefore, use "not" in front of a term to ensure that the search will not include that term. Warning: Some databases use "and not" instead of "not." Check the database help screen.|