Search Ranking

Search engines use algorithms to rank the pages retrieved from a search, so the most relevant pages will be listed first. This is one reason why many searchers only view the first few pages of search results. These ranking algorithms vary from search engine to search engine and may even be considered "trade secrets".

A recent study found that the differences in ranking are evident by comparing results retrieved by several different search engines. (Bar-Ilan, Judit. "Comparing rankings of search results on the Web." Information Processing & Management 41.6 (2005): 1511-1519.)