BOOLEAN LOGIC

A Quick Guide to Make Your Searches Better

Prepared by Mira D. Johnson, SLMS

HOW DO I SPEAK BOOLEAN?• Imagine that you need to find information about jazz or blues music

for a class assignment. To get an overview of what is available before focusing on some aspect of jazz or blues music, you perform three keyword searches.

• jazz OR blues      This search finds articles that discuss either jazz or blues.     OR always broadens a search. 

• jazz AND blues     This search finds articles that compare jazz and blues.     AND always narrows a search. 

• jazz NOT blues     This search finds articles that are exclusively about jazz.     NOT always excludes records with the specified term.    

See, it’s

• It’s just like math. Look at it this way: • Black dots  = records that contain the word jazz• White dots  = records that contain the word blues• Black/White dots  = records that contain both jazz and blues

When to use not

• NOT is appropriate when a word is used in different contexts.

• For example, the search vikings not minnesota retrieves records about Vikings but not the Minnesota Vikings. If you are studying Medieval Viking sagas, this is good. If you are researching pro football, it's not.

(ADVANCED BOOLEAN)• Use parentheses in searches with more than one

Boolean operator

• Sometimes a focused search must combine several related words for one idea with another word or words, as in the search:

(logging or clearcutting) and rainforests

• In this search, we used Boolean OR to combine the related words: logging OR clearcutting. Then we used Boolean AND to combine these words with rainforests. The parentheses ensure that results are what we expect.Again, just like math and , right?

WILDCARDS

• Use truncation. If you want to search for part of a word or a whole word that may have several endings, use a "wildcard," commonly an asterisk (*).  It will improve search results and save you time. For example:

To Find: Use:

legislate, legislates, legislator, legislators, legislation, or legislating

legislat*

Educate, educates, educator, educators, education, educating

educat*

“Exact Phrases”

• Use quotation marks when you’re looking for an exact match. This occurs most often with commonly used compound phrases.

• For example, “nuclear physicist” ,“life expectancy”, “green tea”

Let’s Try…START THE ENGINES

• www.google.com

• www.yahoo.com

• www.bing.com

• www.clusty.com

• www.quintura.com

• www.search-cube.com

Credits• Blum, Justin. “Using AND, OR, and NOT (Boolean Operators).” Mathewson-

IGT Knowledge Center, University of Nevada. 13 June 2008. Accessed 17 Sept. 2009. <http://www.knowledgecenter.unr.edu/instruction/help/booltips.html>.

• “Easy button.” Staples. Accessed 17 September 2009. <www.staples.com>.• Microsoft Clipart.