SOC 344 Research Methods

The three most used Boolean operators are AND, OR, and NOT [they must be typed in all caps]. They connect your search words together to combine or exclude keywords in a search. This helps to narrow or broaden your set of results. 

ProQuest and EBSCO databases and Google search accept Boolean operators.

AND narrows a search by telling the database that ALL keywords used must be found in order for an item to appear in your results list. 

The search: Norfolk AND University  will return items with both terms.

OR broadens a search by telling the database that ANY of the words it connects are acceptable. This is helpful when you are searching for similar terms, such as "cats" or "kittens." 

The search: Norfolk OR University  will return items with either term.

NOT narrows your search by telling the database to REMOVE all terms that follow it from your search results.

This can be useful when:

• you are interested in a very specific aspect of a topic.
• when you want to exclude a certain type of article.

The NOT operator should be used with caution, as you may miss out on relevant results.

The search: Norfolk NOT University will return items that only mention Norfolk.

NOTE: Google uses minus (-) instead of NOT. Learn more in this article directly from Google: Refine Google Searches

 Quotation marks narrow the search to an exact phrase or grouping of words. The AND operator will return items with all the terms but they might not be close to each other. Using quotation marks allows you to search for an exact item.

The search: "Norfolk State University"  will return items with that exact phrase. Much like the use of NOT, be careful using quotes as you might miss items. For example, the above search would not return items that only used "NSU", "Norfolk University", or "Norfolk Univ." 

() Parentheses allow you to combine Boolean operators (AND, OR, NOT).

Use parentheses ( ) to separate keywords when you are using more than one operator and three or more keywords. The order in which the operations are processed can vary between systems. Searches within parentheses are performed first. After this, operations may proceed from left to right or in a preset order of operations, depending on the software you are searching in.

The search Norfolk AND (Virginia or America) will retrieve records containing the two concepts Norfolk + Virginia, the two concepts Norfolk + America, or all three concepts.

If you don't put in the parentheses, the search statement may be processed in a different order, which will affect the quality of your search results. For example, it may be processed strictly from left to right, so that the AND is done first. 

The search Norfolk AND Virginia or America will retrieve records containing both of the concepts, Norfolk + Virginia, or any records that contains the concept America, even if it does not contain the other concepts.

You can use more than one set of parentheses!

For example, the search (Norfolk OR Suffolk) AND (Virginia OR America) will retrieve records containing the concepts: Norfolk + Virginia, Norfolk + America, Suffolk + Virginia, Suffolk + America, Norfolk + Suffolk + Virginia + America...

An asterisk broadens your search by acting as a "wildcard." It allows you to search for variations of words. For more detailed information on how the different databases use wildcards, visit Wildcards.

For example, a search for: univers*  will return results containing words: university, universities, universal, universality, universalism, universalize, universalist, universe, universally, universalness, universalist, and more!