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Advanced Research: Boolean Operators

This guide is for MSJC students and advanced researchers and features topics such as strategic browsing, finding data and using research tips to make your research process better, faster and smarter.

What To Look For

Boolean Operators

Boolean operators form the basis of mathematical sets and database logic.

  • They connect your search words together to either narrow or broaden your set of results.
  • The three basic boolean operators are: AND, OR, and NOT.

Why use Boolean operators?

  • To focus a search, particularly when your topic contains multiple search terms.
  • To connect pieces of information to find what you're looking for.
    • Ex: second creation (title) AND Outliers and Gladwell (author) AND 2008 (year)

Search Order

Databases return results from the commands you enter. Be aware of the order in which words are connected when using Boolean operators: 

  • Databases usually recognize AND as the primary operator, and will connect concepts with AND together first.
  • If you use a combination of AND and OR operators in a search, enclose the words to be "read" together in parentheses.

Ex:  people AND (success OR successful)

       (success OR successful) AND (people)

Using AND

Use AND in a search to:

  • narrow your results
  • tell the database that ALL search terms must be present in the resulting records
  • example: cloning AND humans AND ethics

NOTE:  In many, but not all, databases, the AND is implied. 

  • For example, Google automatically puts an AND in between your search terms.
  • While this may seem to make searching easier, the terms may not be connected together in the way you want.
  • For example, this search: successful people  is translated to:  people AND success AND successful. The words may appear individually throughout the resulting records.
    • (notice using another word with successful)
  • You can search using phrases to make your results more specific by using double "quotes"

Ex:  "successful people" AND "high achievers". The results will display the words as they appear together.

Using OR

Use OR in a search to:

  • connect two or more similar concepts (synonyms)
  • broaden your results, telling the database that ANY of your search terms can be present in the resulting records
  • example: people OR success OR successful.


Using NOT

Use NOT in a search to:

  • exclude words from your search
  • narrow your search, telling the database to ignore concepts that may be implied by your search terms
  • example:  success NOT people