Effective AND Easy

Learn to use Boolean "AND," "OR," and "NOT" operators to make your Web searches less frustrating. Booleans let you narrow your search criteria by specifying that retrieved pages must contain more than one search term (that's the AND operator), must contain at least one of several search terms (OR), or must not contain a certain term (NOT). Unfortunately, not all search engines offer Boolean searching, and those that do implement it in different ways.

AltaVista's Advanced Text Search does Booleans the old fashioned way: cocaine AND mexico AND NOT ("New Mexico" OR soccer OR football OR baseball) will find items that mention cocaine and the nation Mexico, while excluding anything about the state New Mexico, sports, and cocaine-using athletes. (Note the quotation marks around New Mexico. That tells AltaVista that New Mexico is a string--that is, those words must appear together.)

HotBot can interpret that expression, but its Advanced Search page makes it easy with the "Look For" pop-up menu, which includes "all the words" and "any of the words" as choices, and the "Word Filter" pop-up, with choices for "must contain," "should contain," and "must not contain."

Google takes a different approach: It assumes an AND between all search elements, does not support OR at all, and will perform a NOT if you prepend a minus sign to a term. So if you're searching for cocaine AND mexico AND NOT soccer at AltaVista and decide to try the same query at Google, remember to use cocaine mexico -soccer.

Tomorrow: Nichy searches.