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What are Boolean Operators?. Research Skills 8. 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, () and “ ”can be used.
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What are Boolean Operators? Research Skills 8
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, () and “ ”can be used. • They are used to combine search terms when doing research.
No… they aren’t leaning ghosts….
And • Would 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 AND Jeans Sneakers
AND Explained • Using the operator AND between keywords will limit the results of a search because all of the keywords have to be present in order for an item to be retrieved.
OR • Would 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 OR Jeans Sneakers
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.
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
Venn Diagram for NOT Jeans Sneakers
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.
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
( ) or “ ” • Used to group together words or phrases, for example (domestic NEAR violence) and (police AND trial) “domestic violence” “police trial”
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.dogpile.com • www.yahoo.com • www.ixquick.com • www.duckduckgo.com www.altavista.com www.ask.com www.excite.com