Use parentheses to clarify relationships between search
terms.
For example, a search for (television OR
mass media) AND women will retrieve
"women" with either "television"
or "mass media"
Another example, a search for (automobile
OR car) AND sales will retrieve
all records that have the word "sales"
and also the word "automobile"
or "car."
Note: the same effect would not
necessarily result if the parenthesis are omitted.