Boolean Searching

Boolean Operator or Keywords

Boolean searching allows you to group words together in an electronic database or environment such as the World Wide Web to receive a number of different types of results. Depending how you group these word, you will receive different results.

Boolean operators are words that connect a search that may add or subtract a concept to your search. Boolean searching is the most common and basic search strategy.It allows you to expand (return more information or matches) a search by using OR or limit (return less information) a search by using the word AND. Most of the search engines on the World Wide Web allow you to use some form of boolean searching. The following list explains the basic boolean search strategies.

For example:

By using an AND between words you limit the search.

By placing an OR between words it expands the search.

When you use OR you receive more information because the search engine is looking for two words rather than just one word.

Boolean - 'And' queries

Boolean searching allows you to group words together in different combinations to produce a variety of results. The 'and'queries are probably the most used and many search engines defaults to(meaning it automatically using this searching tool) that as a search strategy. It is the simplest to understand.

The query 'beach and California' will find the intersection of all the documents containing the words 'beach', and 'California'

beachCalifornia

The use of 'and' limits the search or makes it smaller. The documents returned will be documents that contain only BOTH of the words beach and California.

Boolean - 'Or' queries

When doing a boolean search with the operator (thats what they call these words that define the search strategies) 'or' will broaden the search or make the search larger.

The query 'beach or California' will find documents that have either word. The document will have either the word beach OR the word California.

beachCalifornia

The query 'beach or California' will find the union of all the documents containing the words 'beach' and 'California'.The use of 'or' increases your retrieval.

Boolean - 'Not' queries

Another type of boolean searching tool is the 'not' operator which allows you to exclude words fro the search.

If a document has a word that you would like to search but that document also contains another word that you do not want to retrieve, then it will exclude that document from you search query results.

beachCalifornia

The query 'beach not California' will find all the documents containing the word 'beach', and excluding the documents containing the word 'California'. The use of 'not' limits your retrieval.