Boolean
Searches
Some search engines require you to insert the "Boolean Operators",
"and", "or," and "not." These words
help you to be more precise, and to narrow or expand your searches,
when looking for your topic.
AND:
The Boolean AND narrows your search by retrieving only documents
that contain every one of the keywords you enter. The more you
enter, the narrower your search becomes. Example: truth AND justice Example: truth AND justice AND ethics AND congress
OR:
The Boolean OR expands your search by returning documents in
which either or both keywords appear. Since the OR operator
is usually used for keywords that are similar or synonymous,
the more keywords you enter, the more documents you will retrieve. Example: college OR university
Example: college OR university OR campus OR higher education
NOT:
The Boolean NOT or AND NOT limits your search by returning only
your first keyword but not the second, even if the first word
appears in that document too. Example: bulimia AND NOT anorexia
NESTING:
Using parentheses (Nesting) is an effective way to combine several
search statements into one search statement. Use parentheses
to separate keywords when you are using more than one operator
and 3 or more keywords. Example: (scotch OR bourbon) AND NOT (beer OR wine)
