The boolean operators are based on the Boolean lgebra and allow to effect operations of character logical-mathematician. These operators are: AND (e), OR (OR) and NOT (NO). The use of these operators can become the search of the recovery much more focused, producing resulted more necessary. More information is housed here: Futurist. OR When using operator OR, is extended searchs it, because a bigger document number goes to satisfy this criterion; any one of the terms will be enough for the recouped document. The more words enter connected for OR, more documents will be gotten.
In such a way, we conclude that operator OR plays a function additive, having as resulted a logical addition. In the Lycos, for example, operator OR could be substituted by the character ( ). In Yahoo! Ask.com operator OR will have to be typed in high box. AND the volume of documents recouped for the previous operator, can be sufficiently extreme. Thus, we can establish priorities or group the terms in subgroups in different aspects. The more terms or concepts to combine in a search using operator AND, little registers will go to recoup, that is, we recoup only those documents that contain both the informed terms.
We conclude in such a way, that the operator functions of conjunctive form, culminating in a logical product. Interesting to notice some points: In the Google and Yahoo! , and already is automatically inserted in the research to each space between the words that we insert. No longer Lycos and in Ask.com, and is substituted by the operator (+). NOT operator NOT excludes definitive registers of its results of search. We conclude operator NOT as soon as possesss action substitute, that is, this operator produces a difference logical. In the Yahoo and the Lycos, the NOT is substituted by the operator (-). NEAR the NEAR is one of developed resources to become still more efficient the boolean search and need.