Small Business Website Design Service
Search 101
The most utilized method of finding information on the web is through search. The 3 major search engines (Google, Yahoo, and MSN) average over 60 million unique visitors a day from the US.
Contrary to common belief, "search" does not rely on keywords alone to return results.
While no one knows for sure exactly all the particulars involved in determining how a page is viewed by the different search engines, there are three general factors that each search engine employs:
Search engines have automated agents (aka bots, crawlers, etc.) that constantly traverse the web and evaluate web pages. The first thing that needs to occur for a page to be included in search results is the crawler needs to know about your site. The second factor is that the crawler needs to determine a page should be included in the search engine's index. For a variety of reasons, not all web pages visited by a crawler are placed in an index.
The search engine crawler evaluates the page and indexes it according to what it determines are the relevant keywords and phrases. The number of times a word appears in the content as a percentage of all words, whether the word is in a heading or title, whether it is in bold or a different color, the font size, etc. all play a part in how the page is evaluated.
The search engine then looks at what other web sites (or pages) link to the page. As part of it's evaluation it considers whether the content at the other site is related to the content it has determined is relevant to the page in question, whether the link from the other site is one-way or reciprocal, and the importance the search engine has placed on the other site. Other factors such as number of visitors to the site, length of time spend on the site, etc. are all factored into this equation. All of this is then retained with the page in the index (in Google terms, this is Page Rank - a number on a relative scale of 0 to 10).
When a simple search is performed,
the search engine goes to it's index (item 1),
matches on keyword relevance (item 2),
factors in page rank (item 3),
and returns the results.
The ability of a search engine to consistently be able to expose and bubble up relevant content greatly determines it's success (there's a reason why something is "Googled" and not "MSNed"). The exact algorithms and factors that each major search engine uses in determining results is a closely held secret (think the formula for Coke).