Metasearch Engine Reviews: MetaCrawler and Inference Find + Boolean Basics: AND and OR Operators - Page 3
© Paula Dragutsky
For example:
apples AND oranges
means exactly the same as
+apples +oranges
The OR operator equals leaving a blank space in front of each subject word (in most search engines). It requires that items resulting from your search contain at least one of the words (or both of the words) joined by OR.
For example: apples OR oranges
means exactly the same as
apples oranges
When you're using the AND and OR operators, you must leave a space before and after AND and OR. It's safest to capitalize AND and OR (although this isn't required in all search engines).
Why are Boolean operators more powerful than plus signs or spaces? Because they can be combined with each other to create very precise searches. For example:
(millennium OR "year 2000")
AND (apocalypse OR "end of the world")
This search statement, translated into a sentence, would read, "Amazing Search Engine - would you please get me items which have either the term "millennium" or "year 2000" (or both) and the term "apocalypse" or "end of the world" (or both)." Search engines read statements from left to right, and consider terms in parentheses as units.
If you think about it, you'll realize that you can't perform the above search using plus signs and spaces.
By the way, some of the results of this search surprised me. I never realized the millennium computer bug was that bad. In my next article, I'll discuss the NOT operator, another Boolean basic.
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