What are Boolean
Operators?
Mrs. Sereno & Mrs. Gadbury
2012
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No…
they aren’t leaning
ghosts….
 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
additionally, () can be used
 In math, they are used to connect
logical statements
 For accessing information, they are
used to combine search terms
when doing research
And
+
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
Would everybody wearing Jeans, please stand
up
# _____

Would everybody wearing tennis shoes please
stand up
# _____

Would everybody wearing jeans AND tennis
shoes please stand up
# _____
Venn Diagram of AND
War
Photography
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
OR
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
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Would everybody wearing jeans please stand
up
#______
Would everybody wearing tennis shoes
please stand up
#______
 Would everybody wearing jeans OR tennis
shoes please stand up
#______

Venn Diagram of OR
War
Photography
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
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
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 tennis shoes, please stand up
Venn Diagram for NOT
Photography
War
()

Used to group together words or phrases,
for example
(domestic AND violence) AND (court OR trial)

could be used to search for cases of
domestic violence that have been gone to
court or trial
Order of operators

Just as in math, certain operators are
done first. The order for Boolean
operators is:
()
 NOT
 AND
 OR

Be sure to use proper search
structure
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
What would the following search bring up?
Dogs AND ((rabies OR rabid) NOT (domestic OR Pet) )




The search will look for the words rabies or rabid
Then domestic or 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 let’s try one on our own in
the WUHS SHARE catalog
I am looking to see if there is any information
about ocean mammals in Alaska, like dolphins
and porpoises, but I don’t need any more
information about whales. What is the best
Boolean phrase to build for this search?
(answer on following slide!)


Alaska AND (dolphins or porpoises)
NOT whales