Definition

• Boolean operators are words or symbols that define a relationship between two or more search terms.
• This enables the increasing or decreasing the results of a search depending on the relationship between the terms.
• These operators are also know as "logical operators."
• In Infotrac databases, Booleans are appropriate in three search modes:
  • Relevance Search
  • Keyword Search
  • Advanced Search

Boolean Operators

• and
  • Usage
    • "and" is used between 2 or more words and/or phrases to narrow a search to just documents that include both terms.
    • This makes your search more precise.
  • Examples
    • biotechnology and research
    • "geographical information systems" and application*.
• or
  • Usage
    • "or" is used between 2 or more words and/or phrases to narrow a search so that documents are located that contain either or both of the terms.
    • This expands the size, "recall," and number of results of your search.
    • It is particularly useful when:
      • There are two or more terms for a particular subject.
      • You want to find either of two terms, as they are both relevant to your information need.
  • Examples
    • biotechnology or bioenginering
    • "white tiger" or "siberian tiger".
• not
  • Usage
    • "not" is used to exclude terms succeeding the boolean operator.
    • This makes your search more precise by excluding documents that may not be relevant.
  • Examples
    • "united states" and rivers not (mississippi or missouri)
    • "mountain lion*" not lynx.
    • clinton and "new york" not hillary