Google's John Mueller spoke about search ranking algorithms that are applied across the site. He mentioned it at the 42:47 mark into the hangout from Tuesday. He said "in general, when we have something that's like a sitewide score, then the current sitewide score applies to everything for that website."
Here is the full transcript from that part:
But in general, when we have something that's like a sitewide score, then the current sitewide score applies to everything for that website.So from my point of view, we don't have anything like a website authority score. But if we did have something like that or if we have-- when we're looking at, for example, quality signals that are more sitewide, then that's something that applies across the whole website in the state that it's at now. So it's not the case that we would say, oh, five years ago, you had this score for your website. Therefore, your contact will be rated like this forever. But rather we look at your website overall now, and we apply the current score to all of your pages on the website. So that's what we do when it comes to sitewide signals.
So it seems that sitewide scores don't have much of a history in terms, at least in the theoretical case he is thinking up. The sitewide score, is the sitewide score in the "current state" not what it was years ago.
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