Search
Engines
This is where the user is actively searching for information through keyword
searches. There are three important elements to search engines: the database, the user
search, and the ranking of results.
The Database is container of indexed description of Web pages. Historically they
were a link list, later becoming a huge link list with a small description for each link.
Now they have special Search algorithms to find needed Web pages by using keywords. Alta
Vista, Excite, Infoseek, WebCrawler, OpenText, Magellan, and HotBot have 80+ million Web
pages indexed.
The average time between submitting your URL and getting it into the database seems to be
5-8 weeks. Most search engines check their databases to see if URLs still exist and to see
if they have been recently updated.
Search engines give each document they find some measure of ranking of the match to
your search query. Relevant scores reflect the number of times a search term appears, if
it appears in the title, if it appears at the beginning of the document or HTML tags, and
if all the search terms are near each other. Some engines allow the user to control
the relevance score by giving different weights to each search word.
Each Search engine uses a different method of ranking. For example, if there are no links
to other files or pages within a file (in other words, a single page Web site), some
search engines will not register this page.
How long does it take to have first
promotion results?
Each Search engine has online databases , but
they overload with requests and some of them need 1 week (for Example - Alta Vista,
Infoseek, What's New). Some of them - 1 month (Excite, Lycos) , and WebCrawler needs 4-5
months !!! No magic bullet to avoid this time delay.
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