Intro:
What's the best search engine? The one you learn to use well.
Search engines can help you find information on the World Wide Web, but you'll get more chaff than wheat unless you learn general search strategies and the particular search syntax for your favorite search engine.
Many people think that the value of a search engine is this: Put in a little information, and you get a lot in return.
But the best searching is based on this principle: Put in a lot, and you might just get back what you want.
The following tips use Boolean logic:
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There are four Boolean operators, or connectors: and, or, not, and near.
These four help you include or exclude pages from your search. And they're required when you type into AltaVista Advanced's Boolean search box. You can't just type army bases georgia to find pages on bases in Georgia. You have to type army and bases and georgia. Some search engines, but not AltaVista, require the connectors to be typed in ALL CAPS.
Imagine two sets of Web pages: those that refer to Mark McGwire and those that refer to Sammy Sosa. Of course, the pages would overlap, but not entirely. By the way, why is the McGwire circle bigger?

And narrows your search to fewer items by insisting that more conditions be met. So you retrieve only those documents containing both words or phrases. This yields the intersection of the two circles:
mcgwire and sosa
Or is the most dangerous word in searching. It widens your search by allowing either item (or one of several possibilities) to be in the text. Both words might be in the text, but not necessarily. So you use or when you're not sure how a word or phrase might be expressed. Or is also good for hedging your bet when you don't know the spelling of a word (feiger or fieger), or when you don't know if a word will be abbreviated (mississippi or miss.) Using or retrieves all of both circles:
mcgwire or sosa
And not narrows the search by leaving out a subset of items, such as mcgwire and not sosa. (Note that tricky part: Some search engines will let you use not, but on AltaVista it's and not. Think of it this way: mcgwire is an item, and not sosa is an item, so if you want both you connect them with an and. (Yes, this one makes my head hurt.)
mcgwire and not sosa
sosa and not mcgwire
Parentheses, as you've noticed, can help you and AltaVista keep straight the Boolean logic. For example, AltaVista evaluates the operators in this order: near, not, and, or. But look at the example mcgwire or sosa and maris. See the problem that arises when the computer looks for an "and" before it looks for an "or." It's not "sosa and maris" that you want emphasized; instead, "mcgwire or sosa" is the first decision you want made. To put it another way, you aren't saying that you want "sosa and maris," but if that can't be found you'll just take any reference to mcgwire, right? You want either of the current ballplayers ("mcgwire or sosa") on the same page with the old player (maris). So sort it out with parentheses: (mcgwire or sosa) and maris.
(mcgwire or sosa) and maris
Near means within 10 words in either direction. (Most search engines don't have this ability.) Near provides a middle ground between finding hillary and clinton on the one hand, which would give you every junior high school graduation list in America, and "hillary clinton," which would be too restrictive and miss references to "Hillary Rodham Clinton" or "President Clinton and his wife, Hillary." So try hillary near clinton to find those words within 10 words of each other, in either direction. Of course, you'll get some false positives, but not too many to look through. Near is also the trick to use when you want results with or without a middle initial in a name. It's also good for narrowing your search by subject; for example, if you need a restaurant by the Spanish Steps in Rome, try something like "spanish steps" near (restaurant or lunch).
Who's to blame for all this?
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Boolean logic comes from George Boole, a British mathematician, who laid out the rules in 1849 on his own Web page, "An Investigation of the Laws of Thought, on Which are Founded the Mathematical Theories of Logic and Probability." Boolean logic merged logic and algebra, laying the foundation for the digital revolution.
George had this to say, "No matter how correct a mathematical theorem may appear to be, one ought never to be satisfied that there was not something imperfect about it until it also gives the impression of being beautiful."
Today's quiz: Find a photo on the Web of George Boole. How about "george boole" and "boolean logic" and image:boole. You'll find this:
George Boole, 1815-1864