Boolean Searching

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Boolean Searching

• LIB 120
• Amanda Izenstark

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Why is it called Boolean?

• Boolean searching is named for its inventor,
  George Boole (1815-1864), an English
  mathematician.
• Boole created a way of describing sets of objects
  using the terms and, or, and not.
• Today we use these terms to search catalogs,
  databases, and search engines.

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AND

• cats --
• cats AND behavior --

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OR

• cats OR felines --
• dogs OR canines --

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NOT

• cats NOT dogs --

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Nesting

• Allows you to combine elements. This search
  looks for articles on cats/felines and behavior,
  but leaves out all the results that discuss dogs
  or canines.
• (cats OR felines) AND behavior NOT (dogs OR
  canines)

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Precedence Parentheses

• When you use nesting, the search in parentheses
  takes precedence.
• That means its performed first, just like in
  math.
• (3x4)113
• (cats OR felines) AND behavior

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Boolean Searching in HELIN

• Youve done this to find encyclopedias
• medicine and encyclopedia
• You can do this to combine ideas to find books
• teenagers and smoking

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Boolean Searching in HELIN

• You can only do this in the Word / Keyword Search
  in HELIN.
• It does not work in the Author, Title, or Subject
  search because these require exact phrases, such
  as a subject heading or an authors name (last
  name first!).

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Boolean vs. Natural Language Searching

• Ask Jeeves and other tools may use Natural
  Language searching -- but most catalogs,
  databases, and search engines use Boolean or a
  variation.
• If you ask a question in a tool that requires
  Boolean, you wont get results.

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More about Boolean in HELIN

• You must use Boolean in HELIN otherwise ANDs
  and ORs might be inserted into your search in
  random places!
• This could make a complete mess out of your
  search, and give you useless results!
• Read the results carefully, and make sure that
  your search wasnt changed.

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Where to get help?

• Most search tools offer some sort of help screen.
  HELINs word search has a help screen at
  http//helin.uri.edu/screens/keyhelp.html