36 replies to this topic

[Peter]

Hi everybody,

In many discussions the Page Rank is always mentioned, refered to, etc. And often there seems to be a different opinion on how to "read" that number. Therefor I'd like to start this topic to figure out what the PR that the Google Tool Bar shows is all about.

First lets look at what Google says it is: "Page Rank is Google's measure of the importance of a page." So what does that mean?

Importance of a page,.... Something can be important only if it is compared to something. Just on it self,... it can not be important. It needs to be compared to something.

What does Google compare to when determining the importance of a page? It will compare to the 2 things it can compare to: Incomming links and outgoing links

Important facts of incomming links:
1) Quantity
2) Link popularity of the page it comes from
3) Keyword comparisement between the 2 pages
4) Keywords in the name of the link
5) Keyword comparisment of all the pages that link to you
6) more

Important facts of outgoing links:
1) Quantity
2) keyword comparisment between the 2 pages
3) Keyword comparisment between all the pages that you link to
4) How many link back
5) more

In no way they use the PR number it self because it is just a number. This number can not be used to determine relevance or quality. It is a conclusion of a research. It says something like this: On a range from 1 to 10, this importance of this page is X.

To give an example: It is a conclusion like this: " This article is very good because it relates very well to its targeted audience and gives an excelent explanation about the topic. Many people have read it!" ---> PR = 6

If this article referes to another article the conclusion says nothing about the article it refers to. Google will have to do the complete research again to determine the PR of the article it refers to.

So my conclusion is: PR says a lot about importance, but I know one thing for sure: It is NOT used to determine the PR of another page.

What you all think?

Best regards,

Peter

[Haystack]

Hi Peter, at a high level, I explain this to clients like this:

When Google reads your web site they've read the text and now know what your site is about. When someone does a search that includes words within your site Google has to decide which site to rank 1st, 2nd, 3rd, etc. for that search phrase. This is largely decided based on Link Popularity so a site with 20 inbound links would likely rank higher than a site with 10 inbound links.

This is reflected in a site's PageRank.

That can be broken down into much more, but that's as much as a client generally needs to know.

[Jill]

Peter, pagerank has nothing to do with outgoing links. It ONLY has to do with the links that are pointing to your page. It has nothing to do with page quality, or keywords, or whether an article is correct, incorrect, good or bad.

PageRank is simply a measure of the number of links to a page.

Where it gets tricky is that links from higher pageranked sites count more than links from lower pageranked sites.

Basically, PR is calculated as votes.

You should read my summary of PageRank Uncovered to understand better what PageRank is and what it isn't. If you understand the summary well, then go for the actual PageRank paper that Chris Ridings wrote (and I edited).

It appears that you don't quite understand what PageRank actually is at the moment. But don't worry, you're not alone as most people don't! Until I edited Chris's paper, I had no idea myself!

Jill

[Peter]

Jill,

Thanks for that link!

I found the paper by the Google founders when they were still in university.

A quote:

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.

T stands for the incomming links
C stands for the outgoing links

T devide by C is a major part of the equation. The more outgoing links you have, the lower your page rank is.

Seems to me that the more outgoing links you have, the lower your page rank will be. That is why a link farm doesn't work I think.

But definitely it seems that the number of outgoing links is a big part of it.

Regards,

Peter

[qwerty]

I'm not a mathmetician (I may not even be able to spell the word ) but I believe that what this means is that the more links you have on a page, the less of that page's PR is passed on to those pages to which you're linking.

That is, if my page has a PR of 6 and I link to 1 page, then that page is getting more of a boost than it would it if my page linked to 5 pages. But that doesn't mean that my page's PR goes down at all because of this. If that were the case, no one would link to anyone.

Note that in the formula you quote, C(A) -- the number of pages linked to by page A -- is not part of the calculation.

[Scottie]

That's a pretty common misconception. Actually, you don't 'lose' PR.

Your page has a vote. If the page only links to 1 page, that page gets 100% of the vote.

If the page links to 20 pages, each one receives 5% of the vote. If the page links to 100 pages, each one receives 1% of the vote.

Your page doesn't lose any PR. However the receiving pages will recieve less impact when there are more links on the page.

Hope that helps!

[Scottie]

You were faster than me that time, Bob!

[Peter]

YEP,.. you all are right. My mistake.

Sorry about that.

In any way,.. that document by the founders of Google is very interesting. I like math, so I am going to read it completely....

Thanks,

Peter

[Peter]

This is great!!!!!

Page ranks helps you get a high rank when searched for something that matches your content. (Without related content your site won't show up of course.)

Get a link from a page with a high page rank that has as few as possible links on it and your page gets a big boost in page rank. So if you have a link from a page that has a PR of 8, and your link is the only link on that page, you will actually have a higher PR than the page that links to you.

This is very usable information. Use this knowledge to increase the PR of your start page by smart internal linking.

I´m gonna give this a lot of thought.

Peter

[qwerty]

The important thing to remember about PageRank is that, for the most part, it only has an effect on PageRank. As I understand it, it's a very small piece of the total ranking algo, so raising a page's PR is not going to do much to raise its position in a SERP.

I've seen a lot of people actually equate PageRank with rank. That's a big overestimation of its value.

[Jill]

Peter, the wonderful thing about PageRank, and why Google has chosen to use it, is because it happens naturally on the Web every day. When people like stuff, they link to it, and that's what Google counts on when determining PageRank.

I strongly believe that PageRank is not something that should be purposely manipulated in order to somehow hopefully increase your rankings. It's something to understand, take note of, and make sure that you don't do things to thwart it.

But it's not something you should think about too much. In other words, you should not say that you won't take a link from a PR3 page, because it's PR is too low. Or you shouldn't specifically go looking only for links from PR8 sites.

Just link to good stuff, create a site that is worth linking to, and you will naturaly get the PageRank that is intended for your site.



Jill

[Peter]

Oh don't worry, I am against every form of ilegally raising rankings. First it is unfair, and besides that, it is risky and in the long run it has more negative effects than positive.

But,.. SEO is exactly what it says it is: Optimization.

What I was thinking of is that it should be possible to raise the PR of a page inside your domain by setting up a linking structure that makes sure that your PR stays inside your domain. When you have a page that gained a PR of 6 and you use that page to link to pages outside your web site,.. You are giving it away.

Using that high PR page to link to your own pages is better, surely from an SEO point of view.

As to links from outside the domain. I don't care about their page ranks. What I do care about is the relevance of the page. If it is relevant, I will be very happy I got that link. If it is not relevant at all,.. ah well,.. then it is just nice.

For me the whole picture needs to be right. A high quality picture of a beautiful car, but hidden behind a few black spots in the picture has little value. A picture that has a little less quality, but shows the complete car is always better.

Regards,

Peter

[Peter]

One interesting thing is that PR is based on random surfing. The chance that a page is found when surfing randomly is your PR (Actually PR is a number between 0 and 1,.. the Google Toolbar just multiplies that number by 10.)

However, nobody surfs the internet randomly. Except for the robots,.. they do surf randomly.

May be just interesting to know,...

I´m sorry if I bore some of you with this topic. I just do like math and PR is based on math,.. accept for that dampening factor d,.... I wish I knew more about the "d".

All I know is that it tries to describe the time that it takes (on average) before people get bored with the page and click further. I would like to know how Google determines what number is given to d for different groups of sites.

Peter

[Jill]

What I was thinking of is that it should be possible to raise the PR of a page inside your domain by setting up a linking structure that makes sure that your PR stays inside your domain. When you have a page that gained a PR of 6 and you use that page to link to pages outside your web site,.. You are giving it away.

Unfortunately, it's more complicated than that.

Ranking to other sites can be good for your search engine rankings for other reasons. If you "hoard" pagerank, it's possible that you can be penalized for that. We don't really know.

But don't think you're the first to think of that. Many people have spent months trying to figure out the best way to link their own pages together for optimimal PR. They come up with some pretty crazy things, imo.

There's hiding links through javascript. There's not linking at all. There's all kinds of directing visitors back to only the home page.

All just crazy PageRank mania things, imo. Just please don't fall into those traps!



Jill