Sunday, July 28, 2013

Domain Authority: The Top Two Factors On Google: A Study of 50,000 Webpages in 5 Countries

Current Study: 50,000 top webpage's for 1,000 keywords in 5 countries

A series of 1,000 keywords was developed covering a variety of topics including professions and trades in various UK localities, website development, marketing, travel and health issues. The webpages on the top page of Google.co.uk (pages from the web) for each keyword were assessed to determine their PageRanks and the corresponding HomePage PageRanks. This was repeated for the USA, Canada, Australia and India using respectively.com.,.ca.,.com.au., and.co.in. The localities (towns or cities) were changed for each country. The findings could have been undertaken manually using either Firefox or Internet Explorer with the Google toolbar active: To simplify the process, a program that undertakes the analyses was used. Accordingly, any or all the results can be easily verified.

Nearly 50,000 top positioned webpages were assessed - some Google results pages do not have the usual full complement of 10 web pages. There were 2,486 webpages on the top Google results page with PR0 (5%). Of these, only 214 (0.4%) were on websites with HomePage PageRank less than 4 or they were not themselves HomePages.

There were 32,179 internal webpages on websites with HomePage PageRank of 4 or more (64%). There were 14,909 webpages on the top Google results page that were themselves HomePages with PR4 or lower (30%). Only 2,912 webpages (5.8%) of the webpages were not the HomePage of the website that were on the top page of Google for a keyword had associated HomePage PageRank of 3 or less.

In this study, 94% of nearly 50,000 web pages on the top Google results page for 1,000 keywords in 5 countries were on Websites with HomePage PageRank 4 or higher or they were themselves HomePages. This study supports the view that the top factor in the Google algorithm is the Domain Authority of the website as indicated by the HomePage PageRank. The second factor is a boost given to HomePages that are competing for a keyword.

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 publicly available.

Google's PageRank is an indication of Google's evaluation of the value of incomming links to a web page. 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 web page 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 Home Pages that are competing for keywords - like handicap in golf.

In this study, there were 2,486 web pages on the top Google results page with PR0 but only 214 were on websites with HomePage PageRank less than 4 or they were not themselves HomePages.

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.

Implications of the top two factors in the Google algorithm.

HomePage PageRank can be used as a guide to keyword difficulty provided allowance is made for the effective boost in PageRank to HomePages competing for keywords.


Websites with low HomePage PageRank, which includes new websites, only have a realistic chance of top page positioning on Google for relatively low difficulty keywords and, even then, only with their HomePage.

GlobeTek Inc.
Timothy R. Srobenhorst
President
(920) 819-7199
Timothy@freeonlinewebsitedesign.org

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