From Wendy Boswell,
Your Guide to Web Search.
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Definition:

What is Boolean Search?

Boolean searches allow you to combine words and phrases using the words AND, OR, NOT and NEAR (otherwise known as Boolean operators) to limit, widen, or define your search. Most Internet search engines and Web directories default to these Boolean search parameters anyway, but a good Web searcher should know how to use basic Boolean operators.

Where does the term Boolean originate?

George Boole, an English mathematician in the 19th century, developed "Boolean Logic" in order to combine certain concepts and exclude certain concepts when searching databases.

How do I do a Boolean Search?

You have two choices: you can use the standard Boolean operators (AND, OR, NOT, or NEAR, or you can use their math equivalents. It depends on you, the searcher, on which method you're more comfortable with. For example:

Boolean Search Operators

• The Boolean search operator AND is equal to the "+" symbol.
• The Boolean search operator NOT is equal to the "-" symbol.
• The Boolean search operator OR is the default setting of any search engine; meaning, all search engines will return all the words you type in, automatically.
• The Boolean search operator NEAR is equal to putting a search query in quotes, i.e., "sponge bob squarepants". You're essentially telling the search engine that you want all of these words, in this specific order, or this specific phrase.

  Next term: Crawler

Pronunciation: BOO-le-un

Also Known As: Boolean, boolean logic, boolean search, boolean operators, boolean operands, boolean definition, boolean searching, boolean commands

Examples: Using AND narows a search by combining terms; it will retrieve documents that use both the search terms you specify, as in this example:

• Portland AND Oregon

Using OR broadens a search to include results that contain either of the words you type in.

• liberal OR democrat

Using NOT will narrow a search by excluding certain search terms.

• Oregon NOT travel