Rockwell Schrock’s Boolean Machine pictured on the left is a simple way of demonstrating how operator words (and, or, not) function in a search engine.

Application for Educators
Schrock’s boolean machine is a simple way to show students how the terms “and”, “or”, “not” affect the outcome of a search. It is a simple program to use. To use the boolean machine simply hold your mouse pointer over each word and you will see an explanation of how each operator word affects the search outcome.