# Boolean Search

## Definition(s)

• A search technique that utilizes Boolean Logic to connect individual keywords or phrases within a single query such as AND, OR, and NOT, within (w/5) , and NOT withinN (not w/5). 1 2
• A Keyword Search in which the Keywords are combined using operators such as “AND,” “OR,” and “[BUT] NOT.” The result of a Boolean Search is precisely determined by the words contained in the Documents. (See also Bag of Words method.) 3
• The term “Boolean” refers to a system of logic developed by an early computer pioneer, George Boole. In Boolean searching, an “and” operator between two words results in a search for documents containing both of the words. An “or” operator between two words creates a search for documents containing either of the target words. A “not” operator between two words creates a search result containing the first word but excluding the second. 4 5 6
• A search type using Boolean logic operators between search terms that indicate a relationship between them. An “AND” operator between two words or other values (for example, “pear AND apple”) means one is searching for documents containing both of the words or values, not just one of them. An “OR” operator between two words or other values (for example, “pear OR apple”) means one is searching for documents containing either of the words. 7
• Mathematical query language developed by English mathematician George Boole in the 19th century. Boolean searching of text is based on the underlying logic functions of various true/false statements. Common Boolean operators are “and,” “but not,” and “within.” 8
• A search for information using “AND,” “OR” and “NOT” commands, such as “Tom but not Jones” or “bankruptcy and trustee.” 9
• The use of the terms “AND,” “OR” and “NOT” in conducting searches. Used to widen or narrow the scope of a search. 10