What to look for. Boolean operators form the basis of mathematical sets and database logic. 1  They connect your seach words together to either narrow or broaden your set of results.2  The three basic boolean operators are: AND, OR, and NOT. For example, Google automatically puts an AND in between your search terms. 2  Though all your search terms are included in the results, they may not be connected together in the way you want. 3  For example, this search: college students test anxiety is translated to: college AND students AND test AND anxiety.