Google's John Mueller in this mornings Google Hangout said at the 4:37 mark into the video that Google doesn't tend to give advice around algorithms.
Yes, for manual actions, they try to give specific advice. But when it comes to being hit by Panda or Penguin or any search quality algorithm, Google says they tend not to give advice.
He said in response to being asked for advice:
I don’t know if I can give you specific examples there. We tend not to do that for algorithms when they review the site. Unless it is something really obvious that we can point out. Where we can say well, your home page has hidden text or something like that. For technical reasons that might be something where we can give examples. With search quality algorithms that is usually where we can’t give any specific examples from our side.
Here is the video clip:
From experience watching Google help webmasters, this is accurate. Truth is, I think it is often very hard for Googler's like John Mueller to find an example of why a site may be hit by Panda. Often you see him struggle with it when he is asked about specific cases.
Forum discussion at Google+.
