UPDATE: Rolling back an adjustment which had adverse effects on DA and PA scores.

[IanWatson]

UPDATE:

Yesterday's (June 4, 2018) adjustment to our DA/PA metrics turned out to have some unanticipated adverse effects. We're rolling back the adjustment, so by midday tomorrow you should see your scores return to what they were earlier this week. We're also implementing some new procedural checks on our end to help make sure it doesn't happen again. We sincerely apologize for any stress or burden this may have caused.

We also want to emphasize that DA and PA are relative metrics. The scores will fluctuate slightly with the index, and for that reason, should be used to compare your site with others. We realize this isn't always easy to explain to clients and stakeholders, so we're working on ways to help you all report these metrics in ways that minimize the potential for confusion.

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We are continuing to improve our Domain Authority and Page Authority algorithms and strengthen our link index.

As of today, June 14, 2018, You may notice a slight variation in current and historic DA/PA scores in Link Explorer and tools that incorporate our new link data such as Campaigns, Keyword Explorer, and MozBar. This is due to a planned adjustment on our end that could be more noticeable than our standard updates. We made this adjustment in order to account for the rapid growth of our link index over the past 6 months and and stabilize distribution of scores over time.

For customers who have been tracking DA scores over time, you may want to make note of this adjustment date in your reporting.

Rest assured that our DA and PA scores are still far more stable and accurate than they were previously in Open Site Explorer. Our index is now 20 times larger (and growing) and updating daily rather than monthly, therefore standard fluctuations in the index are far less noticeable in your score than before.

DA and PA will still always fluctuate slightly and naturally with the index. As the landscape of the internet changes, so should our index to reflect those changes. Whenever we make an update on our end that could be noticeable on your end, we will let you know.

Also, please remember that DA and PA scores should always be understood as relative to other sites’ scores in the index, and reported to clients in relation to their competition and not as a standalone metric of individual performance.

If you have more questions about DA or the difference between the new score in Link Explorer vs. the old score in OSE, please read this FAQ page, or post a question below and I or a Mozzer will reach out.

Thank you!

Ian

[GastonRiera]

Thanks for the update Ian!

Also read something in Twitter from Rand about this issue.

Its great to hear that Moz keeps track on the bugs and when they screw up, embrace the problem, do the best to solve it, even rolling back.
Keep up like this!

Best wishes.
GR

[dohertyjf]

Got it, thanks so much Ian!

[IanWatson]

Hey John,

Some issues arose around Spam networks and Tumblr sites skewing the distribution. Over the last 12 months, these two types of sites outperformed (i.e., gained links and linking plds faster) most 'real' sites. This caused sites outside of these to appear to be trending down in DA, relative to the performance of those other networks. This makes sense, because this is precisely what spam networks are designed to do so, and tumblr.com is currently treated as a TLD, so it's easy for tumblr blogs to gain large numbers of linking PLDs (because they're free to create and link heavily to one another).

We do need to get this normalization work added to the index, but we need to do so in a way that does not allow these types of networks to have too much sway in the distribution. We will ensure that the communication of that change is clear and easy to communicate to other stakeholders for users.

[dohertyjf]

Hi ian, for those of us interested can you share the issues that are causing this update to be rolled back? Also, I like many saw the update and have to explain things to clients and bosses, so it would Ben rest to get a post on the main blog about what’s changing and why things are fluctuating more than usual.

[IanWatson]

Hi Dawn,

I want to bring your attention to an update I just added to this post. It seems there were some unexpected issues with the index update we released yesterday and scores should not have been affected as dramatically as they were. You were right to question and I am very sorry for the shock.

[IanWatson]

If you could send your site to ianw@moz.com, I would be happy to take a look and talk to my team about BOTW.

[IanWatson]

Across the board there was been a shift in DA as we index more of the web. We are finding more links to all sites, but the relative number we find to those mid range DA sites is fewer than what we are finding to sites like BBC and NYTimes.

This normalizing of DA scores ensures that scores don't continue to climb just because our index size increases. Rather DA should climb when we find more new links to a specific site over others.

We are also very close on our Links via Redirect work, so some of these sites will see a nice bump in link counts once we are able to pass that equity from the redirects they have.

[sfh]

Thanks

Understood that relative DA might be more meaningful, but there seems to be something funny going on across the range of websites I track.

My website has a https://www.skillsplatform.org/ had a DA of 40 which appears to have been adjusted down to 31 and now recently 28. This comes despite the number of LRDs increasing over the same period.

All the organisations I track by comparison have dropped as have the DA for my parent company and the competitors in that space. These are all top draw highly respectable websites.

• http://www.skillsforhealth.org.uk/ - Down to 43 from 55 in sept 17
• https://www.skillsforcare.org.uk/Home.aspx - Down to 47 from 57
• https://hee.nhs.uk/ - Down to 51 from 60
• https://www.nhsemployers.org/ - Down to 49 from 58

It seems strange that all these website have been effectively brought down a category. Is a DA 30 the new 40? Even highly respectable UK charity websites have seen a drop from 70 to 62 such as https://www.autism.org.uk/

Yes it's all relative, but many of us had KPIs around domain authority and often DA is used as a sign of website strength when pitching for advertising. Further guidance on reasoning behind this would be appreciated. It seems there's been a drop in website DAs across the board apart from mega sites such as BBC.

[NgEF]

Much obliged for the update! I was checking on a backlink profile just yesterday and had seen the domain authority increase to 21 and then when I checked back again today, it was down to 20 again. I'm curious on one thing. Moz Local submits to BOTW, but why do we not see the BOTW link in the backlink profile from Link Explorer? I'm guessing that BOTW should be one of the sites indexed as well correct?