In a recent video Hangout, Google’s John Mueller has said that Panda considers site quality as well as the site architecture.
Answering to a question at 8:58, “Does Panda take site architecture into account when doing Panda score or would fixing those categories make no difference at all?"
John said, Panda is something general that takes into account everything around the site. He said, “So that is something where if we find issues across the site where we think this is essentially affects the quality of the web site overall, then that is something that might be taken into account there.
So if you are saying that your category pages are really bad and that is something you really can improve then that is something I’d work on, I’d work to improve.”
Panda Considers Site Architecture, Says Google!,