25-06-2012, 02:37 PM
The Google PageRank Algorithm and How It Works
PageRank.ppt (Size: 386 KB / Downloads: 57)
What is PageRank
PageRank is a link analysis algorithm which assigns a numerical weighting to each Web page, with the purpose of "measuring" relative importance.
In short PageRank is a “vote”, by all the other pages on the Web, about how important a page is.
How is it Calculated?
The PR of each page depends on the PR of the pages pointing to it.
But we won’t know what PR those pages have until the pages pointing to them have their PR calculated and so on.
So what we do is make a guess.
Intuitive Justification
A "random surfer" who is given a web page at random and keeps clicking on links, never hitting “back”, but eventually gets bored and starts on another random page.
The probability that the random surfer visits a page is its PageRank.
The ‘d’ damping factor is the probability at each page the "random surfer" will get bored and request another random page.
A page can have a high PageRank
If there are many pages that point to it
Or if there are some pages that point to it, and have a high PageRank.