If you're considering investing in Google or you use this popular Internet searching system, you may wonder how in the world the amazing thing works.
To answer users' queries, the system founded six years ago by two Stanford University graduate students has scanned and stored nearly 4.3 billion Web pages.
In computer jargon, Google's "search engines" use robotic "spiders" - special software programs - that "crawl" continuously along the myriad trails of the World Wide Web, "harvesting" documents as they go. A separate piece of software builds an index of every word the spiders find.
When a user submits a query - such as "Mount Everest" or "Bill Clinton" - the search engine checks the index, fetches each document that contains those words, sorts them by relevance and returns the most pertinent ones first.
To improve the results, Google uses a patented method called "PageRank," a sort of popularity contest that tries to determine which documents are likely to be most valuable to the user.
For each page, the PageRank system counts the number of other pages that are linked, or connected, to it. In essence, Google interprets a link from Page A to Page B as a "vote" by Page A for Page B.
In addition to the number of votes a page receives, the system analyzes the status of the pages that cast the votes. Popular pages weigh more heavily in the calculation.
Google uses other tricks as well to determine a document's ranking. Words in a special typeface, bold, underlined or all capitals, get extra credit. Words occurring close together - such as "George" and "Bush" - count for more than those that are far apart.
Finally, Google returns the documents that match a user's query, ranked in order of their relevance as determined by their page rank.
Be the first to comment on this article!