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# Thread: Pagerank and its mathematics: Explanation needed

1. Registered User
Join Date
Sep 2009
Posts
1

## Pagerank and its mathematics: Explanation needed

Hello Good people,am not so sure if this should go here,i am student who is interested in developing a search engine that indexes pages from my country.I have been doing my research on Algorithm to use for sometime now and i have found HITS and PageRank as the best out there.I have choosing to go with PageRank since it is more stable than the HITS Algorithm(so i read).

I have found countless articles and university researches about PageRank but my problem is that i do not understand most of the mathematical symbols that form the algorithm in this papers.Currently,i cannot understand how the Google Matrix(the irreducible,stochastic matrix) was calculated with the algorithm,i do not seem to understand the Algorithm used.

I did my reading from the articles below:

http://online.redwoods.cc.ca.us/inst...al2-Screen.pdf
http://ilpubs.stanford.edu:8090/386/1/1999-31.pdf

Please i need you to help me go through it,i need a basic explanation(examples will be nice) with less mathematical symbols.

2. Registered User
Join Date
Dec 2007
Posts
12

## Pagerank and its mathematics: Explanation

Hello,

Do not worry too much about the mathematics. PageRank alone does not determine much. It has to be combined with many other factors such as document relevancy, term relevancy etc...

The concept of Pagerank is simple - how many good pages link to you and how strongly they link to you.

A good page is one that is in turn linked by many other other good pages. As you can see this is kind of "recurrence" equation. In simple terms, If you are linked to by a page that is linked to by many other pages, each of which are linked to by many more other pages, then you are a good resource, to be treated as having good page rank.

But, consider this case: if you are pointed by a page, which also points to ten thousand other sites, then you are not "strongly" recommended by that page - isn't it?

In other words, it is not enough for a "good" page to have a link to you, but it should also have a link to you "strongly", meaning it should have as less other links as possible. For example, a great product download site (such as CNet) points to your website. No doubt, CNet is a good site with high page rank and it points to you, making you a good page - but what is the point, it also points to some hundred other websites - you are just one of the hundred - so your page rank goes down.

It might sound little bit complex - but try to think intuitively and its pretty easy.

To understand it in further simpler terms - consider you have a good friend who is well known and famous. Since you are his friend, you are also treated with respect. But, if you are his *only* friend, then you get more respect, dont you? Thats all.

Have nice day.

P.Gopalakrishna
Creator of CFugue, the World's first and only highlevel MusicNote Programming Library for C++
http://gpalem.web.officelive.com