Moz posted a big update to their index this week that had a big impact on Moz Page Authority and Domain Authority. Why does it matter?
Really it doesn’t matter, but since Google is so secretive the Moz data gives us some insight into what Google (and other search engines are likely seeing). The changes to Moz have no direct effect on search results or traffic. What Moz believes (and it makes sense they are right) is that the updates better match what Google (and the others) see.
Basically Moz found some weaknesses in their prior data and methods and have tried to improve them, as they explained here. Many sites are noticing lowing Page Authority and Domain Authority numbers for their site (as I am on mine). I am not clear yet, but it seems possible, their was a general inflation in the numbers and so say the average number might have declined by 20% (this is just a made up number for illustration purposes). If that were true what really matters is if you declined less (that would be good) or more (that would be bad) than 20%.
And of course, there will be lots of variation in the changes in scores. These scores move around a fair amount (though Domain Authority scores do seem fairly stable over time) even when no big changes are happening at Moz.
Comments on the fluctuations of DA and PA scores from Rand Fisken- DA/PA Fluctuations: How to Interpret, Apply, & Understand These ML-Based Scores
because Mozscape indices take 3-4 weeks to process, the data collected in an index is between ~21-90 days old.
Since Domain and Page Authority are on a 100-page scale, the very top of that represents the most link-rich sites and pages, and nearly every index, it’s harder and harder to get these high scores and sites, on average, that aren’t growing their link profiles substantively will see PA/DA drops.
PA/DA are created using a machine-learning algorithm whose training set is search results in Google. Over time, as Google gets pickier about which types of links it counts, and as Mozscape picks up on those changes, PA/DA scores will change to reflect it.
My strongest suggestion if you ever have the concern/question “Why did my PA/DA drop?!” is to always compare against a set of competing sites/pages. If most of your competitors fell as well, it’s more likely related to relative scaling or crawl biasing issues, not to anything you’ve done
Rand provides lots of good insight here. Moz is generally followed closely by people that pay a great deal of attention to SEO. I am not really in that camp, I pay some attention just because I find it interesting. I don’t spend time trying to figure out how to increase SEO through various gimmicks.
I don’t pay much attention to ratings for other sites, based on his suggestion I might start tracking a few similar sites to see how their scores vary over time as a way of understanding my scores better. All I really did before was look at other sites authority scores and comparing when I was bored (maybe 2 or 3 times a year) but didn’t keep track of any of them.
I find Moz interesting because it gives us open access to interesting data. There are many other things that impact search results but the authority pages and sites have is an interesting thing to watch (and does have a real impact on search results – even if it is much less than people might suspect).
Earlier this year I wrote about Decreases in MozRank and Page Authority for some of my sites and I posted an update where most of the decreases had disappeared (the authority numbers had returned to the same or close to what they were before the decline). Hopefully that will happen for my sites this time too, but we will have to wait and see.
Related: Most Important Search Engine Ranking Factors – Find MozRank, Moz PageAuthority, Google PageRank and Alexa Results Now – Keeping Up with SEO Changes