Some search engines recognize ANDNOT or AND NOT instead of NOT. Produces search results that exclude the keyword after the operator. Example: aliens NOT illegal immigrants Using the NOT operator will narrow down your search because it will tell the search engine to exclude the keywords after the NOT operator. The NOT operator is useful when you are trying to eliminate instances of similar words. A person doing research on aliens from another planet may not care about illegal immigrants. In the diagram below the area of the circles represents the number of hits your keywords will produce. Using the NOT operator requires that the search engine exclude any hits that contain "Illegal Immigrants". As a result, the shaded area is restricted to the section that covers only "Extraterrestrials". Notice that the overlapping area of the circles is also left unshaded. The NOT operator will elliminate any hits that include "Illegal Immigrants" even if those hits include "Extraterrestrials".