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What are Boolean Operators?

What are Boolean Operators?. Mrs. Mersand December 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 used

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What are Boolean Operators?

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  1. What are Boolean Operators? Mrs. Mersand December 2007

  2. 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 used • They are used to combine search terms when doing research • In math, they are used to connect logical statements

  3. No… they aren’t leaning ghosts….

  4. And • Would everybody wearing Jeans, please stand up # _____ • Would everybody wearing Sneakers please stand up # _____ • Would everybody wearing jeans and sneakers please stand up # _____

  5. Venn Diagram of AND Jeans Sneakers

  6. AND Explained • Using 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.

  7. OR • Would everybody wearing jeans please stand up #______ • Would everybody wearing sneakers please stand up #______ • Would everybody wearing jeans OR sneakers please stand up #______

  8. Venn Diagram of OR Jeans Sneakers

  9. OR Explained • Using 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.

  10. NOT • The 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

  11. Venn Diagram for NOT Jeans Sneakers

  12. NOT Explained • Not 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.

  13. NEAR • Finds the terms within 10 words of each other • Domestic NEAR Violence • would make sure these two words appeared close enough to each other that they would be referring to domestic violence

  14. ( ) • 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

  15. Order of operators • Just as in math, certain operators are done first. The order for Boolean operators is: • ( ) • NEAR • NOT • AND • OR

  16. Be sure to use proper search structure • What would the following search bring up? Dogs AND ((rabies OR rabid) NOT (domestic OR Pet) ) • The search will look for the words rabies and rabid • Then domestic and pet • Then remove all results that contain the words domestic or pet from the results • Then remove anything that does not contain the word dog from the results

  17. Now lets try some on our own • You should always use more than one search engine when you are doing research • Try thinking out of the box, give Google a break!! • Other options • www.mama.com • www.dogpile.com • www.yahoo.com • www.surfwax.com • www.ixquick.com • infomine.ucr.edu • www.lii.org • www.ipl.org • www.nettrekker.com • www.altavista.com

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