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A search engine is a
means of looking through a database of web pages for topics or words of interest. |
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Two basic types of
search engines
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Categorical
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Classify sites by
category. This is usually done by people submitting sites for certain
categories. These submissions are then reviewed and placed appropriately. |
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Generally have less
"hits" (matches), but what is found is appropriate. |
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Example http://www.yahoo.com |
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Key Words
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Searches are done by
either intentionally placed key words or whole text listings. |
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Results in many more
hits, but they can be far off base. |
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Example http://www.altavista.com |
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To compare try typing
"Cancer Signs" into this databases. |
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Search engine
technology is advancing.
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Some search only page
titles, and others do better jobs at ranking relevancy. |
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Hybrid engines (e.g. http://www.metacrawler.com) search many other
engines at once. |
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You can find lists of
search engines simply by pushing the search button. |
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Advanced Searches
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Each search engine
has its own rules for multiple word searches, and there is usually information on how it
works close to the search box. |
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Example Yahoo
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Click on the options
box next to the search, then help, and the query syntax. |
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You will see that you
can use "and," "or," and "-" (not) to restrict your search,
in addition to other options (this would help with the cancer signs, you could try
"cancer signs -zodiac"). You may also use wildcards and require phrases. |
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Example Alta Vista
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Alta Vista has
similar options (look in the help index), and you can also "refine" your
searches by category after the first stage. |
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