Boolean logic defines logical relationships between terms in a search. The Boolean search operators are and, Taylor Leisure winter Skirt Casual Ann LOFT or and not. You can use these operators to create a very broad or very narrow search.
- And combines search terms so that each search result contains all of the terms. For example, winter Leisure LOFT Ann Taylor Casual Skirt Casual Taylor Ann Leisure winter LOFT Skirt travel and Europe finds articles that contain both travel and Europe.
- Or combines search terms so that each search result contains at least one of the terms. For example, college or university finds results that contain either college or university.
- winter Leisure Taylor LOFT Ann Casual Skirt Not excludes terms so that each search result does not contain any of the terms that follow it. For example, television not cable finds results that contain television but not cable.
- When executing a search, And takes precedence over Or.
- When you search EBSCO Discovery Service, your library administrator may require Boolean Operators be capitalized (AND, OR, NOT).
The following table illustrates the operation of Boolean terms:
|Skirt Taylor winter LOFT Casual Leisure Ann And||Or||Not|
|Each result contains all search terms.||Each result contains at least one search term.||Results do not contain the specified terms.winter Mine Jacket Mine Jacket Leisure Leisure winter Jacket Leisure Leisure winter Mine 4ttqwREaU|
|The search heart Leisure LOFT Ann winter Skirt Taylor Casual and lung finds items that contain LOFT Skirt Ann Casual Leisure winter Taylor both heart and lung.||The search heart or lung finds items that contain either heart or items that contain lung.||The search heart not Skirt Leisure LOFT Taylor Ann Casual winter lung finds items that contain heart but do not contain lung.|
When a single Find field is displayed, you can enter search terms in the Find field, and combine with AND, OR, and NOT. (For example, Roosevelt NOT Franklin.)
When Guided-Style LOFT winter Ann Taylor Skirt Casual Leisure Find fields are displayed, you can enter search terms in each Find field, and select AND, OR, and NOT from the Boolean drop-down lists.
With longer search strings, you can combine many terms in a search with the AND operator, which will narrow your search results. For example, heart AND lung AND bypass AND artery will provide a more focused search than heart AND lung OR bypass OR artery.
To make even better use of Boolean operators, you can enclose search terms and their operators in parentheses to specify the order in which they are interpreted. Information within parentheses is read first, and then information outside parentheses is read next. For example, (heart OR lung) AND bypass will return different results than heart OR lung AND bypass.
Using Booleans and Parentheses
To make even better use of Boolean operators, you can use parentheses to nest query terms within other query terms.
You can enclose search terms and their operators in parentheses to specify the order in which they are interpreted. Information within parentheses is read first, then information outside parentheses is read next. For example,
When you enter (mouse OR rat) AND trap, the search engine retrieves results containing the word mouse or the word rat together with the word trap in the fields searched by default.
If there are nested parentheses, the search engine processes the LOFT Ann winter Leisure Taylor Skirt Casual innermost parenthetical expression first, then the next, and so on until the entire query has been interpreted. For example,
Taylor Leisure winter Casual Skirt Ann LOFT ((mouse OR rat) AND trap) OR mousetrap
Using Booleans When Phrase Searching
When Boolean operators are contained within a phrase that is enclosed in quotation marks, the operator is treated as a stop word. When this is the case, any single word will be searched for in its place.