PageRank (PR) is Google’s evaluation of the importance of a webpage as determined by the total value of links to it within Google’s index of webpages.
Achievability in keyword research - Quantifying keyword difficulty.
If you target keywords that are too difficult for your webpages to achieve top page positioning on Google, you will waste time, effort and money. The following video demonstrates a simple and free technique that quantifies keyword difficulty.
The value of every link is calculated as the PageRank of the linking page divided by the number of outgoing links on it as Matt Cutts of Google explains in the following video:-
Relevance. "As Larry Page said long ago, we want to give you
back “exactly what you want.” When Google was founded, one key innovation
was PageRank, a technology that determined the “importance” of a webpage by
looking at what other pages link to it, as well as other data. Today we use
more than 200 signals, including PageRank, to order websites, and we update
these algorithms on a weekly basis." -
It is helpful to consider each link as carrying ‘link juice’. One link authority unit is the value of a link from a page with PR1 and with one outgoing link.
In the above slide, Matt Cutts is showing us that if one page has 100 units of link juice and 2 outbound links, then those two outbound links have 50 units of link juice. The lower page has 9 units of incoming link juice and three outbound links; each of the three outgoing links from this page has 3 units of link juice. Matt tells us that “this is the literally the idea behind PageRank. It’s that simple.”
PageRank is Google's evaluation of Domain Authority and Webpage Authority
You can see the PageRank of the page you are viewing with Internet Explorer or Firefox browsers with the Google toolbar installed.
Google recognises authority of a webpage by the incoming links from other websites.
- Invariably, every page on a website has a link to the HomePage.
- Incoming links to internal webpages will result in some link juice going to the website's HomePage.
- The HomePage of a website usually has the highest PageRank of all the pages on the website.
- The value of each incoming link depends on the authority of the linking page divided by the number of outgoing links on it.
- The PageRank of the HomePage of the website indicates the importance (domain authority) of the website.
- PageRank is on a scale of 0-10 with top pages such as Google having PageRank 10.
- The PageRank scale is logarithmic.
Examples of PR10 websites - usa.gov; facebook.com
PR9 bbc.co.uk; nytimes.com/
Major national media websites tend to have PRs 7-9.
There are many directory websites.
- Examples are directories of professions and directories for localities. These typically have PRs 4-7.
Only a minority of small or medium sized business websites achieve PageRank greater than 4.
HomePage PageRank - The Top Factor in the Google Algorithm
Many SEO experts consider PageRank to be irrelevant because the PageRanks of many webpages on the top Google results page for competitive terms is 0. Here is a typical quote - "There are millions of low (or ZERO) PR pages rankings VERY prominently in search for competitive terms - what more proof do you need? (Page 1).”
|Danny Dover has led the SEOmoz team. In his
book Search Engine Optimization Secrets (2011) he makes the
"domain popularity is extremely useful for raising the powere of weak pages. Even if the number of links to a given page is low, it can still rank hiughly if this metric is large. Currently, we see this all the time with Wikipedia." (p 75)
"Google makes scraping (automatically requesting and distributing) the PageRank metric difficulty." (p 10)
The google.co.uk results page for 'York decorator' showing 6 directory websites - all internal pages - and 4 small business websites - all HomePages.
In the following table, the PageRanks of the above top webpages for 'York decorator' and the corresponding HomePage PageRanks have been included - Columns B and C.
|PageRank||HomePage PageRank||Adjusted HomePage PageRank|
In the above table, two webpages (#4 and #5) on the top Google.co.uk results page have PageRank0.
The #5 page is an internal page on a directory website and my contention is that the top factor in the Google algorithm is the HomePage PageRank which for this website is 5.
The webpage in #4 is itself a HomePage so without adjustment the HomePage PageRank remains 0.
The second factor in the Google algorithm (IMHO) is a hidden boost given
to HomePages with PageRank 4 or less when they are competing for keywords
and my best estimate is 4.5 as seen in column D.
The team at Google is remarkably adept at revealing a little information whilst concealing many key facts.
The PageRank (PR) of the webpage we are browsing appears in an indicator on the Google toolbar (Internet Explorer or Firefox only). We are only shown integer values of PageRank and not the decimal places known to Google (PR 4 rather than 4.6788834 for example).
Google determines PageRank of a webpage in two stages.
1. It summates the value of all the incoming links to the webpage. The value
of each link is dependent on the PR of the linking page divided by the
number of outgoing links on that page.
2. Every page indexed by Google is ranked according to the total value of its incoming links. This is derived mathematically and is independent of such factors as relevancy or anchor text. The webpages are not in 11 groups (PR0 -10) but in a continuous league because of the decimal places known to Google.
HomePage PageRank is the Top Factor On Google – Development of a Theory
I opened a medical website 11 years ago based on my information leaflets that I gave to my patients.
Some of my webpages, themed on relatively low difficulty keywords, were regularly in #1 on Google.
At various times, three of my webpages dropped from #1 to #2 for a few months.
- The question was "What did the pages that were now in #1 position have that my demoted, #2 pages, did not?"
- From a clinical point of view, not one of the new #1 pages was as technically correct as my own.
- From an on-page search engine optimisation
(SEO) point of view, they did not seem to be particularly impressive.
- Scoring checks with Website Auditor and Internet Business Promoter confirmed that my webpages had significantly better scores.
- That left off-page optimisation - links from websites - as the other option to be checked.
- The new #1 webpages had one or two incoming links with
minimal link value (SEO Spyglass) and PageRanks 0.
- Again, my pages had more link juice and PageRanks 1 or 2.
- There was no obvious explanation for the new webpages achieving #1 position
according to the literature.
- Here was a fascinating opportunity for research.
- There was one common element to the three webpages that had pushed three of
my #1 webpages to #2:
- They were all articles published by journalists in a variety of national newspapers' websites.
- Whilst the PageRanks of the new #1 webpages were all 0, the Homepage PageRanks (HPR) ranged from 6 to 8.
- Their observations were confirmed but all the internal web pages they were quoting with PR0 had HPRs 4 or more.
- Most of these top page positioned webpages with PR0 for medium keyword difficulty were themselves Homepages.
Confirming the top two factors on Google.
To test the validity of the top two factors as explained above, you can do a search on any keyword on Google with either Internet Explorer or Firefox with the Google toolbar active.
- Check the PR of any of the webpages on the top Google SERP and also the corresponding HomePage PageRank.
- If one of the top webpages is a HomePage with PR less than 5, add the G-Factor 2 boost so that the adjusted HPR becomes 4.5.
10 Hidden Key Facts You Need To Know About Getting To The Top Of Google
- HomePage PageRank (HPR) is the top factor in the Google algorithm: Compelling and readily verifiable evidence has recently been published that demonstrates this (G-Factor-1). A pop-up appears by the indicator when we hover the cursor over it informing us that "PageRank is Google's view of the importance of this page" followed by a number/10. The author believes that we should read this more fully as - "PageRank of the HomePage is Google's view of the importance of this page - number/10".
- Google gives a boost to the effective PageRank of a HomePage that is competing for a keyword; this is the second factor in the Google algorithm (G-Factor-2).
- We are only shown integer values of PageRank and not the decimal places known to Google (PR 4 rather than 4.6788834 for example)
- As PageRank has many decimal places, changes to PageRank as far as Google is concerned, are usually no more than a small upward or downward slide along a continuous curve. If a webpage has an HPR of 6.00001 we will see it as PR6. Even if the total value of incoming links to the page stays constant, the Google index of webpages is expanding and this page may slip to a PR of 5.99999 but we will see it as PR5 at the next PageRank update. In terms of positioning on the SERPs, there would be no change because, from Google's perspective, there has been virtually no change in PR.
- Google frequently updates PR information for itself but only releases updates to the public at intervals varying between a few weeks to many months.
- When PageRank updates are released, they are already out of date by at least three months.
- Google tells us that 'Page' in PageRank relates to one of the two Google co-founders - Larry Page. Whilst this is undoubtedly true, it also refers to the webpage.
- If all the other factors (there are at least 200) of two webpages competing for a keyword are identical, the one with the higher HPR would be listed above the other in Google's search engine results pages (SERPs).
- Google does not keep us fully informed about those links to a website that it recognises. A 'link:URL' search on Google will return only a few of those revealed by other search engines.
- The best indicator of keyword difficulty is the average adjusted HPR (allowing for the G-Factor-2) of the webpages on the top Google search engine results page (SERP) - HPR-KD. These tend to be in a narrow range.
The most popular webpages have PR10. PageRank is on a logarithmic rather a linear scale.
PageRank is Logarithmic
Experts are divided as to the base number of the log scale but one group (SEOMoz) with good quality data, suggest that it is to a base somewhere between 8 and 9. If it is 8 this would mean that for every webpage with PR10 there would be 8 with PR9, 64 with PR 8, 512 with PR7 and 858,993,452 pages with PR0.
The resultts of a pulished study shows the relationship between the number of backlinks and PageRank for 500 HomePages.
The Relationship Between PageRank and Backlinks - EzineArticles.com David Viniker
Google moved ahead of its search engine competitors by incorporating user signals into its positioning algorithm. Initially this focused on PageRank but the recent Panda updates take into account additional signals such as time spent on a website. Reassuringly, published keyword difficulty data analyses before and after Panda have demonstrated that the average HPR-KD for a cohort of 1000 keywords has remained stable. Those webpages that were demoted by Panda have been replaced by others with similar HPR.
The majority of respected search engine optimizers have come to the opinion that PageRank has lost most of its earlier importance and many regard PageRank these days as irrelevant. It is impossible, retrospectively, to evaluate the importance of PageRank when it was first introduced into the Google algorithm more than a decade ago. The literature, however, would suggest that the PageRank of the individual page played a major role in determining positioning on SERPs at that time.
There are many examples of internal web pages with PR0 having top page positioning on Google for extremely competitive keywords. Clearly, PageRank of internal pages is not currently a major factor in the Google algorithm. It is this observation that has led so many SEO experts to give little import to PageRank in webpage positioning.
Domain Authority and HomePage PageRank
Search engine optimisers are agreed that incoming links to webpages are even more important than webpage content in determining webpage positioning on the search engines such as Google.
It is apparent to anyone regularly conducting searches on the internet that some websites, such as Wikipedia, often appear on the top search engine results pages. Such domains are said to carry authority that lifts them up the positioning algorithms. It is a matter of conjecture as to how Domain Authority is best defined.
SEOmoz's Domain Authority represents their expert's best prediction about how a website will perform in search engine rankings. They recommend using SEOmoz Domain Authority when comparing one site to another or tracking the "strength" of a website over time. SEOmoz's Domain Authority is calculated by combining all their other link metrics (linking root domains, number of total links, MozRank, mozTrust etc.) into a single score. The SEOmoz's Domain Authority involves a complex derived formula the details of which are not made publically available.
Google's PageRank is an indication of Google's evaluation of the value of incoming links to a webpage. It is determined in a two-step process:
- Each link recognised by Google to a webpage is given a value according to the PageRank of the page giving the link and this is divided by the number of outgoing links on that page. The value of all the incoming links to that page is then summated.
- All webpages indexed by Google are placed in a table such that those with the most incoming 'link juice' are at the top - PageRank 10. We see webpage PageRank as integers 0-10 although Google knows the decimal places. PageRank is on a logarithmic scale and SEOmoz suggest that it has a base between 8 and 9 rather than the more conventional base 10. If it is 8 this would mean that for every webpage with PR10 there would be 64 with PR 8, and 858,993,452 pages with PR0.
PageRank was initially of importance as it related to individual pages but there have been important changes. Google tells us "When Google was founded, one key innovation was PageRank, a technology that determined the "importance" of a webpage by looking at what other pages link to it, as well as other data. Today we use more than 200 signals, including PageRank, to order websites, and we update these algorithms on a weekly basis." It is apparent that PageRank relates now to websites and not only to webpages. The most obvious indicator of website PageRank is the PageRank of the website's HomePage.
The majority of web professionals have come to disregard PageRank as having meaning in search engine optimisation mainly because there are many webpages with PageRank 0 on Google's top results pages for highly competitive keywords. This appropriately leads to the conclusion that the PageRank of a webpage cannot be the top factor in the Google algorithm. However, I have previously indicated that the majority of top positioned webpages with PR0 are either on websites with HomePage PageRank of 4 or more or these webpages are themselves the HomePage of the website.
The Boost in Effective HomePage PageRank to HomePages that are competing for keywords - like handicap in golf.
In this study,
there were 2,486 webpages on the top Google results page with PR0 but only
214 were on websites with HomePage PageRank less than 4 or they were not
Google must be providing a boost in effective PageRank to HomePages that are competing for a keyword. This can be compared to the handicap system that allows golfers at different skill levels to compete. From an SEO perspective, this means, for example, that small businesses with websites that rarely achieve HomePage PageRank greater than 3, can compete with locality or trade directory websites that typically have HomePage PageRanks between 4 and 7. In practice, the boost to HomePage PageRank is to about 4.5.
HomePage PageRank is the top factor in the Google algorithm.
The internal webpages with PR0 on the top page of Google for high difficulty keywords, however, are invariably found on websites with HPR of at least 4 and often 6 or more. It became apparent that whereas the PageRank of an internal webpage has no major influence by itself in the Google algorithm, the HomePage PageRank of the website is the top factor.
There are also examples of webpages with HPR0 having top page positioning
for medium difficulty keywords but careful observation shows that it is the
HomePage itself that is competing. This observation formed the basis for the
conclusion that Google assumes that the HomePage of a website has the
greatest authority and Google is providing a boost to its competitive PR.
HomePages with HPR0-4 have their effective HPR boosted to 4.5. There is no
visible increase when the HPR is 5 or greater.
50,000 Top Webpages Study = UK USA Canada Australia and India
The PageRank of the top pages on Google (UK, USA, Australia, Canada and India) for 1000 keywords (approximately 50,000 webpages) on:-
are presented on '5 Countries 1000 KWs 50,000 webpages'
94% of the top 50,000 webpages are either
- On websites with HomePage PageRank of 4 or more. (G-Factor-1)
- They are HomePages. (G-Factor-2)
You can check the PageRank of the top Google results pages and the
corresponding HomePage PageRanks manually.
KeywordSEOPro will do this on
automatic pilot for you. It is the best keyword difficulty tool available.