MachineMachine /stream

The story of Google’s algorithm begins with PageRank, the system invented in 1997 by cofounder Larry Page while he was a grad student at Stanford. Page’s now legendary insight was to rate pages based on the number and importance of links that pointed to them — to use the collective intelligence of the Web itself to determine which sites were most relevant. It was a simple and powerful concept, and — as Google quickly became the most successful search engine on the Web — Page and cofounder Sergey Brin credited PageRank as their company’s fundamental innovation.

But that wasn’t the whole story. “People hold on to PageRank because it’s recognizable,” Manber says. “But there were many other things that improved the relevancy.” These involve the exploitation of certain signals, contextual clues that help the search engine rank the millions of possible results to any query, ensuring that the most useful ones float to the top.

Web search is a multipart process. First, Google crawls the Web