Google PageRankAs most of you know by now, Google PageRank is a measure of a site's popularity on a scale of 0-10, with 10 being the highest. It mostly depends on the number of nofollow and dofollow backlinks on your blog, and it is one of the factors that effect your SERP (Search Engine Result Page) position.
Moz Domain AuthorityNow the Domain Authority metric by Moz is a bit like PageRank in the sense that it is a domain-level rank. But it is more concerned with how a website will perform in search results. It is measured on a scale of 100, and is updated frequently - once or twice every month.
Differences between PageRank and Domain AuthorityTo get a better understanding of why people are trending more towards Domain Authority these days, let us look at the difference between the two rank metrics.
FrequencyMoz Domain Authority, at any given time, is usually more up-to-date than Google PageRank. Pr only gets updated quarterly - every three months. But DA changes once or twice every month. So even if a site has radically improved, its PR might not get updated for another couple of months, which is a lot of time.
AccuracyGoogle PR is measured on a scale of 0-10, which I think is one of the biggest problems with it. Google rates itself as 9, so you can really only go from 0 to 8 (rarely 9). Since the gradation is so crude and abrupt, you can't tell if you're going up or down or staying at the same place when you get the same PR score two times in a row. It's like being only able to adjust your thermostat in degrees of 10. Imagine going from 20 degrees to directly 30 degrees. There's no middle ground, no way to tell apart two temperatures both in the 20s.
With Domain Authority, you get a much finer scale of 0-100. So you now get a hundred grades instead of just 10. So you can monitor your progress and trends in much greater resolution, or detail.
DepthGoogle PageRank is broadly based on the number of nofollow and dofollow links and backlinks. But there's a lot of other things that Google doesn't disclose. So when you see a PR figure of, let's say 5, you don't get to know the breakdown of points, or in other words, you don't know what things contributed towards this score. So we can see a lot of opacity in Google PageRank.
Domain Authority, on the other hand, is more transparent, and it tells about your progress in areas like Linking Root Domains, Total Links, MozTrust, MozRank, and so on. This way, you get to know exactly where you are going wrong.
ImportanceGoogle employees have this tendency to disregard the actual importance of PageRank. They always advise people not to put much stock into it, as it is only one of the 200 signals Google uses to rank pages on SERPs.
"We only update the PageRank displayed in Google Toolbar a few times a year; this is our respectful hint for you to worry less about PageRank, which is just one of over 200 signals that can affect how your site is crawled, indexed and ranked. PageRank is an easy metric to focus on, but just because it's easy doesn't mean it's useful for you as a site owner."
On the other hand, Moz Domain Authority is relatively gaining momentum, and the constant improvements are making it more and more accurate and reliable. Who knows, in the coming months, DA might actually become a lot more important than PR?
Effect on SERPsAlthough Google PR might not be given as much importance as DA in terms of search ranking, Google PR still has some effect on the SERP, whereas DA does not. This is probably why people still go for PR.
Another reason why PageRank is so popular is that, it is measured by Google. There's a whole psychological effect related to it, and people automatically tend to trust it. PR has been around for so long that almost everyone now knows about it.
So what do you think about Domain Authority? Will it overtake PageRank, or is Google too big to let that happen? Leave us with your responses in the comments section below. And as always, feel free to ask any questions. Cheers :)