Searching the World Wide Web for authoritative sources of information about a given topic can be a daunting task. Consulting Google to track down “jaguar,” for example, generates an alarming list of more than 7 million documents—a mad muddle of entries about cars, animals, sports teams, computers, and a town in Poland.
One reason for Google’s current success as a search engine, however, is its uncanny ability to place relevant documents high in its listings. An important component of Google’s winning recipe for judging relevance is an algorithm that tabulates “votes” on a Web page’s importance. Each link to a page counts as a vote of support for that page. Pages to which many other pages point rank higher than those to which few or no pages point.