Explaining Google Pagerank
Date Added: January 03, 2008 11:58:37 PM
Pagerank is an algorithm that Google uses to assist in ranking websites in their search engine. The algorithm analyzes link structures on the internet and views each link as a vote for the page it is linking to. When you are thinking of ways to optimize your website for the search engines it is a good idea to have a basic understanding of how pagerank works.
Pagerank History
Pagerank was originally conceived at Stanford University by Larry Page. Thus the name “Page”rank was born. He and Sergey Brin began working on the project in 1995 and later became a Google prototype in 1998. It is interesting that the pargerank trademark belongs to Google which was founded for management of the search engine that used pagerank, yet the patent for pagerank belongs to the University of Stanford.
Since its inception Google has grown to be the largest search engine in the world and accounts for almost two thirds of the internet searches. The algorithm for pagerank is still one of the factors Google uses in determining sites rankings within search results. It has marketing executives that specialize in search engines all over the world studying it constantly.
The Algorithm for Pagerank
It has been explained the concept for pagerank is really based on each link being a vote for the site it points to. The votes are not equal because they are weighted by the pagerank of the page where the link originates. It means there is recursive analysis of the linking structure of the internet.
As new websites come online they will accumulate pagerank as they become enmeshed into the linking structure with each site that links to it. Each page that links to the new site will in turn pass some pagerank to the new site. The amount of pagerank that is passed depends on a couple factors. That is the pagerank of the page the link is on and the number of other outgoing links on that same page. The higher the pagerank of the linking page, the more pagerank is passed and the less links on the linking page the higher the passed pagerank.
Remember this is the basic concept and the actual pagerank algorithm used by Google is far more complicated than is covered here. Other things are also taken into account such as relevancy of linking sites and additional factors.
The raw data for pagerank is theorized to exist as a floating point value for each page which is constantly being updated by the Google robots. The pagerank that everyone sees in the Google toolbar is expressed on a 1 through 10 scale, and only updated every three months approximately.
To conclude by describing pagerank in a context of voting does a fairly good job, but it is not quite as democratic as it sounds. Each link carries its own weight and worth determined by the pagerank it has from the inbound links to it. Therefore some pages “votes” have more worth than others. To improve pagerank requires more inbound links from other web pages.
