The Boolean operator NOT eliminates a specific search term or group of search terms. For instance, in our search for anthrax, we may retrieve unwanted articles pertaining to the heavy metal band called Anthrax. Using the search strategy "anthrax NOT heavy metal" essentially means that all documents that contain the phrase "heavy metal" will be removed from your search for anthrax.

The NOT operator is used very infrequently and should only be used when you are confident you will not eliminate articles or other information that could be useful.