Please, Explain These SEO-Metrics!

Since the Linkscape integration in the 8.5 version, Advanced Web Ranking’s reports were flooded with lots of new SEO metrics.

As not all people know the meaning of these metrics, I have decided to make this post an explanatory sheet of the seven most important metrics SEOs use.

I structured the information as best I could, so that you won’t waste time reading pretty stories but get right to the bottom of things. Here it goes:

Page Rank (PR)

Scale: 0 – 10 (integer numbers)

Formula: PR indicates a webpage’s popularity across the web. This means that it only takes into account how many links are pointing to a page, regardless of their quality or anchor text details.

Also, most important you must keep in mind that PR can only be calculated for a webpage and NOT for a website.

Calculated by: Google

Although Google updates PR calculus for webpages often and very often (we’re talking about hours) those values are not available to us. Google makes PR public through the PR Toolbar which is only updated once in a 3 to 9 months period.

The PR toolbar is available for free and you can find the instructions on how to enable it on this page.

Analysis: Although it’s the most popular SEO metric, PR is no longer a determining ranking factor, neither a relevant metric for SEO analysis. PR is only one of the 200 signals Google looks at when determining websites’ position in search results and a rough meter for a webpage’s inbound links.

You can efficiently use it to compare the link profile of different pages and to spot eventual penalties from Google, but you must keep in mind that a drop in your PR can be due to other reasons, than a penalty or removed links.

You PR fluctuates according to all the other pages on the internet because of the way PR is calculated. At first it is determined what it takes to be a PR 10 and from there all the other PRs are set. So, if the webpage with the most links across the internet has a PR 10 and increases even more its number of links, you might see a fall in your PR without having any changes in your link profile.

MozRank (mR)

Scale: 0 – 10 (two decimal numbers)

Formula: mR is meant to mimic Google’s PR. Therefore it only evaluates a page’s link profile taking into consideration the number of links.

There are though a few differences between mR and PR:

  • sometimes, when a website is caught to be performing bad seo practices, it gets penalized by Google through a PR drop. This punishment won’t be reflected in mR and thus differences will appear.
  • mR is calculated as a decimal value to better represent a page’s performance while PR has integer values.

Calculated by: SEOmoz

SEOmoz has its own index of the web (Linkscape) based on which it calculates a set of seo metrics: mozRank, mozTrust, Domain mozRank, Domain mozTrust, Page Authority and Domain Authority. SEOmoz refreshes its link database about once per month, when these metrics are also re-calculated and updated.

SEOmoz provides free access to mozRank, to PA and DA through its mozBar, while mozTrust, Domain mozRank and Domain mozTrust are available only to paying members of their community.

Analysis: Just like PR, mR is calculated logarithmically. This means that the distance between two consecutive mR points progressively increases. The number of built links that took you from a 2 mR to 3 mR, won’t be enough to take you from a 7 mR to 8 mR. The higher the mR, the tougher will be to make progress.

This is where the two decimal points of mR come in hand. You can get a more accurate image of your position and better monitor your progress.

MozTrust (mT)

Scale: 0 – 10 (two decimal numbers)

Formula: mT sums up for a webpage the trust of its referrers determining thus its own trustworthiness. It’s important to be mentioned that not all of your built links are able to pass through trust. Only authoritative websites (.edu, .gov, .edu and well established websites) are counted for determining mT.

Calculated by: SEOmoz

Analysis: Comparing to mR which counts links and improves along with their number, mT is a metric that focuses more on quality rather than quantity. The latter should give you a sense of your page’s long term built strength.

You can use it as a raw number or you can compare it to mR. The rate between mR and mT shows you the overall quality of your link profile and helps you understand what you  should do to improve your performance.

Domain level mozRank & mozTrust (DmR/DmT)

Scale: 0 – 10 (two decimal numbers)

Calculated by: SEOmoz

Formula: These are mR and mT calculated not for a webpage, but for the entire domain.

As many SEOs do, you must not mistake the domain wide metrics with the metrics of your Index page. Although it is the most powerful page of your website, the Index page does not reflect the performance of your entire domain.

Analysis: Domain wide metrics are extremely useful for evaluating your potential partners. For example, you should never judge a guest posting opportunity or a link building prospect by their page metrics. Instead, keep in mind that it’s far more effective to connect with low rank pages on strong and authoritative domains rather than seeking higher rank pages on less powerful domains.

Page Authority (PA)

Scale: 0 – 100 (integer numbers)

Calculated by: SEOmoz

SEOmoz uses a machine learning algorithm to determine correlations between link metrics and high rankings, aggregating them into the PA score.

Formula: PA is meant to aggregate all the other SEO metrics into one and to reflect how prone/promising a page is for high rankings, considering only its link profile.

Just like a fit person will probably perform any sport better that a non-active person, webpages with higher PA are more likely to achieve high rankings than pages with low PA.

Analysis: By comparing PA for the top 10 competitors on a specific search query, you will notice that PA is not fully correlated with rankings. This means that pages with lower PA may rank better than other more authoritative pages due to all the others factors Google is taking into consideration other than link metrics.

However, PA is still the best rough indicator of a page’s stand alone performance in terms of optimization.

Domain Authority (DA)

Scale: 0 – 100 (integer numbers)

Calculated by: SEOmoz

Formula: DA is PA calculated for the entire domain.

Analysis: Unlike PA which is only relevant for optimization purposes, DA is a great metric for competitive analysis and partner selection.

Even more…

As most of these metrics are calculated by SEOmoz, plenty of information and insights on the subject can be also found on their website. Please feel free to use the comments or Twitter, to add your contribution to this post. Any corrections or thoughts are appreciated.

Photo credit: Jack Amick

About Dana Loiz

Dana Loiz is an Online Marketing Strategist at Caphyon. She is passionate about her job and always in a mood to chat about SEO, Internet Marketing and Social Media. She tweets the news at @awebranking and you can also find her on Google+.

  • Stephen Marshall

    thanks for the article Dana! It makes things clearer. This is great info!

    • http://twitter.com/dana_loiz Dana Loiz

      Thanks for your comment, Stephen! I’m glad it was helpful 

  • http://ca-booster.com/ agence communication pme

    Very useful indeed, shouldn’t those informations be part of a contextual help box in the soft itself ? I’ve been for months trying to guess what was the meaning of those values.

    Thank you for those explainations

    • http://twitter.com/dana_loiz Dana Loiz

      Our developers are currently working on a new Help-assistant that should enable users to quickly access all the resources available on the website, and it will probably be available in the next version. So, more help is on the way! :)

  • http://twitter.com/seovavavoom seovavavoom

    Thanks for this :) The day SeoMoz goes
    bankrupt, the world of SEO will be in trouble and we might need to go back to
    the best tools out there: our brain and eyes…

  • https://plus.google.com/106092818158094174234/posts Ketan Raval

    thats a good loved it ..  there are some more rank that I am worried about it is authrank and edgerank ..

  • http://www.kaushalam.com/search-engine-optimization.html Kaushalam

    Google PR is still a more popular metric in SEO, earlier it was used to confirm the best linkbuilding resources if the website contain a PR higher than 3!!