Parentheses to Avoid Confusion
If you're using more than one Boolean connector, you should include parentheses ( ) to make it clear to Lexis-Nexis exactly what you're searching for.
For example, if you were searching for stories about medical malpractice cases against doctors, you might want to use the word malpractice, but then use the OR connector to retrieve stories in which either the word doctor or the word physician also appeared.
Thus you might do a search like this:
malpractice AND doctor OR physician
But is that a search for stories in which the word malpractice appears along with either the word doctor or physician?
Or is it a search for stories in which both the words malpractice and doctor appear, along with any stories in which just the word physician appears?
In this case, Lexis-Nexis would perform the first of these two possible searches, but in other cases where you string together different Boolean connectors you may get results very different from what you intended.
To clear up any such confusion, use parentheses to group the words around the Boolean connectors you use.
Thus to clarify this search you could use parentheses in this way:
malpractice AND (doctor OR physician)
Which specifies that you want stories in which the word malpractice appears along with the word doctor or with the word physician.
Or let's say you were searching for statistics on whether car sales were going up or going down. You might do a search like this:
car sales AND statistics AND percent AND (increase OR decrease)
You also can "nest" one set of parentheses inside another if you are doing a very complex search. See the segment search section of this guide for an example of a search in which a set of parentheses is nested inside another set of parentheses.