What are Boolean Operators?
Mrs. MersandDecember 2007
Boolean operators are named after George Boole, an Englishman, who invented them as part of a system of logic in the mid-1800's. The most common Boolean operators are AND, OR, NOT and NEAR, additionally, () can be usedThey are used to combine search terms when doing researchIn math, they are used to connect logical statements
Nothey arent leaning ghosts.
AndWould everybody wearing Jeans, please stand up # _____
Would everybody wearing Sneakers please stand up # _____
Would everybody wearing jeans and sneakers please stand up # _____
Venn Diagram of ANDJeansSneakers
AND ExplainedUsing the operator AND between keywords will limit the results of a search because all the keywords have to be present in order for an item to be retrieved.
ORWould everybody wearing jeans please stand up#______
Would everybody wearing sneakers please stand up#______
Would everybody wearing jeans OR sneakers please stand up#______
Venn Diagram of ORJeansSneakers
OR ExplainedUsing the OR operator results in either or both of your search terms appearing in your results. Using the OR operator will result in a larger number of retrieved items and therefore expands the search.
NOTThe NOT (or AND NOT) operator forbids the word after it from appearing in the items resulting from your search.
Would everybody wearing Jeans but NOT sneakers, please stand up
Venn Diagram for NOTJeansSneakers
NOT ExplainedNot helps to limit your search because it takes out a category of undesirable results.NOT or AND NOT thus narrows or limits a search by excluding the keyword immediately following it.
NEARFinds the terms within 10 words of each otherDomestic NEAR Violence would make sure these two words appeared close enough to each other that they would be referring to domestic violence
( )Used to group together words or phrases, for example
(domestic NEAR violence) and (police AND trial)
Brings could be used to search for domestic violence that has been interrupted by the police or gone to trial
Order of operatorsJust as in math, certain operators are done first. The order for Boolean operators is:( )NEARNOTANDOR
Be sure to use proper search structureWhat would the following search bring up?
Dogs AND ((rabies OR rabid) NOT (domestic OR Pet) )
The search will look for the words rabies and rabidThen domestic and petThen remove all results that contain the words domestic or pet from the resultsThen remove anything that does not contain the word dog from the results
Now lets try some on our ownYou should always use more than one search engine when you are doing researchTry thinking out of the box, give Google a break!!Other optionsinfomine.ucr.eduwww.lii.orgwww.ipl.orgwww.nettrekker.comwww.altavista.com www.mama.comwww.dogpile.comwww.yahoo.comwww.surfwax.comwww.ixquick.com