In a hangout that Google’s Gary Illyes did with Bruce Clay yesterday, the topic of Panda came up.  While many SEOs refer to Panda as a penalty, and some argue it acts like a penalty, it is actually considered a search filter, since it is applied after the core algo.  And Illyes said that they don’t think of it as a penalty at all.

So with Panda, we don’t think as a penalty. About Panda we think more as a general ranking update. And long term, I would like to change people’s perception about how they think about Panda, for example, because in our view it’s really not a penalty.

Illyes talks about it more as an adjustment to ensure that sites prominent in the search results are ones that have great content for the query and not sites that don’t have great content to match the queries.

Illyes has talked previously about how Google sees many of the algo adjustments not as penalties but rather filters, particularly the duplicate content filter, which most SEOs still continue to call a duplicate content penalty.