PageRank : What is it & How is it calculated ?

[Shadab]

Pagerank

PageRank is one of the methods Google uses to determine a page’s relevance or importance.

PageRank is also displayed on the toolbar of your browser if you’ve installed the Google toolbar (Google Toolbar). But the Toolbar PageRank only goes from 0 – 10 and seems to be something like a logarithmic scale:



Some Definitions :

PR: Shorthand for PageRank: the actual, real, page rank for each page as calculated by Google. This can range from 0.15 to billions.

Toolbar PR: The PageRank displayed in the Google toolbar in your browser. This ranges from 0 to 10.

Backlink: If page A links out to page B, then page B is said to have a “backlink” from page A.


Calculating the PR :

PageRank is a “vote”, by all the other pages on the Web, about how important a page is. A link to a page counts as a vote of support. If there’s no link there’s no support (but it’s an abstention from voting rather than a vote against the page).

Quoted from the original Google paper :

We assume page A has pages T1...Tn which point to it (i.e., are citations).

The parameter d is a damping factor which can be set between 0 and 1.
We usually set d to 0.85. There are more details about d in the next section.
Also C(A) is defined as the number of links going out of page A.

The PageRank of a page A is given as follows:

PR(A) = (1-d) + d (PR(T1)/C(T1) + ... + PR(Tn)/C(Tn))

Note that the PageRanks form a probability distribution over web pages,
so the sum of all web pages' PageRanks will be one.
PageRank or PR(A) can be calculated using a simple iterative algorithm,
and corresponds to the principal eigenvector of the normalized link matrix of the web.

Source : http://www.iprcom.com/papers/pagerank/

[daredevil]

read it a long time back from the same source.Dont know how they got one!!

[ISRdesign]

thx for this NFO man

[sryk]

it could have changed over time and google will never tell you its actual method of calculation

[iBlaze]

Thanks for the info!

[Shadab]

Originally Posted by iBlaze

Thanks for the info!

No problem, mate !

[Stepho]

Many people make the mistake of thinking that PR is the give all and take all of SEO.

Google takes many different aspects into account when ranking sites in the SERP's, and Google will never tell us what these factors are, we can only make some educated guesses and do loads of research on what works and what doesn't.

[MakeMoneyOnline]

Thanks for the tip. There are several pagerank predication tools on the web. Iweb is one site that offers the tool for free.

[topgun]

hey man as far as i know the page rank is calculated as
It usually takes at least three full months for all of your inbound links to be calculated and counted as backlinks. Google's PageRank is calculated based on the relevancy, quantity and quality of your inbound links, as well as the number of outbound links there are on your website. Generally speaking, the fewer outbound links a website has the better.

The higher the PR of your inbound links, the more PR is assigned to your website

[rajshree]

Thanks for good information.......