What are Boolean Operators and How Do I Use Them in my Search?
Introduction to Boolean Logic
Boolean operators return accurate online search results by manipulating the search values stored in each operator using Boolean logic. Boolean operators are simple words used in online database searches that narrow down the information returned when using Internet search engines. Most of today’s search engines depend upon Boolean queries to limit the scope of needed information from online databases and websites.
Boolean operators used as conjunctions to combine or exclude keywords in a search include the following operators.
The logical operator AND is used in an online search to narrow the results returned by the search and to ensure that the database will return all the requested search items. The truth-value is “true” if both search terms are true and “false” if one or both of the search conditions are false. If one search item is found online and the other is not, only information for the item found in the search request will be returned.
The OR Boolean operator connects two or more similar concepts to retrieve records or pages containing two or more search terms by communicating to the database that the requested information should be retrieved. The truth-value is “true” if one or both of the individual conditions are true. It is “false” if both included conditions are false.
NOT is used to ensure that certain words won’t be returned in the search request. The Boolean operator excludes specified search words and narrows the scope of the search by directing the database to ignore specified concepts. The true value is “true” if the condition is false. If the condition is true than the value returned is “false.” AND NOT is similar to NOT. The first term is searched, then any records containing the term after the operators are subtracted from the results.
The Boolean logical operator NEAR is the equivalent of using quotes around a search query term. It is a way to communicate to the search engine that information for the entire search words are requested to be returned in accordance with the specified order or phrase.
Search Tips for the Use of Boolean Operators
Identify search concepts.
List keywords and corresponding synonyms for each search concept.
Use the Boolean logical operators to establish the logical relationships for each search keyword.
Use an advanced or Boolean search option if it is available to specify logical relationships for search terms.
Vary the information requested in each search statement and connect these alternate search terms using the OR operator.
Use the Boolean NOT to keep out unwanted terms that will eliminate receiving too many search results or search results that are not relevant.
Only use the most important concepts with the AND Boolean operator to broaden the subject.
Add alternate terms or spellings for individual concepts and connect with the OR Boolean operator.