In response to our story on Google confirming a Penguin refresh is needed to recover from Penguin, Google's John Mueller added more context to his answer in the Google Webmaster Help thread.
In short, he made a few points:
(1) Even when Google runs an algorithm update or refresh, the "changes aren't immediately visible even after a refresh, that's normal," John said.
(2) A single site is "never in a void alone with just a single algorithm," many algorithms impact a single site.
(3) In "some cases where a site is strongly affected by a single algorithm," but John added "that doesn't mean that it won't see any changes until that algorithm or its data is refreshed."
(4) "Theoretical void of just your site and a single algorithm," John said, "you'd need to wait for the algorithm and/or its data to refresh to see any changes based on the new situation."
In summary, John is explaining that changes in rankings happen to sites impacted by Penguin as well. Because a site impacted by Penguin is also likely impacted by other algorithms. If you clean the Penguin side up, you are likely also cleaning up things with other algorithms that may be negatively or positively impacting your site. Thus you may see changes, slowly, during the Penguin hit, until Google releases the full Penguin update.
Here is the full post by John, I recommend you read it a couple times:
Let me try a longer answer :-)In theory: If a site is affected by any specific algorithm or its data, and it fixes the issue that led to that situation, then the algorithm and/or its data must be refreshed in order to see those changes. Sometimes those changes aren't immediately visible even after a refresh, that's normal too.
In practice, a site is never in a void alone with just a single algorithm. We use over 200 factors in crawling, indexing, and ranking. While there are some cases where a site is strongly affected by a single algorithm, that doesn't mean that it won't see any changes until that algorithm or its data is refreshed. For example, if a site is strongly affected by a web-spam algorithm, and you resolve all of those web-spam issues and work to make your site fantastic, you're likely to see changes in search even before that algorithm or its data is refreshed. Some of those effects might be directly related to the changes you made (other algorithms finding that your site is really much better), some of them might be more indirect (users loving your updated site and recommending it to others).
So yes, in a theoretical void of just your site and a single algorithm (and of course such a void doesn't really exist!), you'd need to wait for the algorithm and/or its data to refresh to see any changes based on the new situation. In practice, however, things are much more involved, and improvements that you make (especially significant ones) are likely to have visible effects even outside of that single algorithm. One part that helps to keep in mind here is that you shouldn't be focusing on individual factors of individual algorithms, it makes much more sense to focus on your site overall -- cleaning up individual issues, but not assuming that these are the only aspects worth working on.
All that said, we do realize that it would be great if we could speed the refresh-cycle of some of these algorithms up a bit, and I know the team is working on that. I know it can be frustrating to not see changes after spending a lot of time to improve things. In the meantime, I'd really recommend - as above - not focusing on any specific aspect of an algorithm, and instead making sure that your site is (or becomes) the absolute best of its kind by far.
Cheers John
The Google algorithm(s) is one big melting pot of zeros and ones.
Forum discussion at Google Webmaster Help.
