What are Boolean Operators?

1 / 17

# What are Boolean Operators? - PowerPoint PPT Presentation

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

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about 'What are Boolean Operators?' - flynn-mendoza

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

### 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
• They are used to combine search terms when doing research
• In math, they are used to connect logical statements
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 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
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
( )
• 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 operators
• Just as in math, certain operators are done first. The order for Boolean operators is:
• ( )
• NEAR
• NOT
• AND
• OR
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
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