synthese - 10:44 pm on Jun 25, 2012 (gmt 0)
I would like to believe that just a single metric would be the answer (and I haven't paid much attention to exit rate until now), but I've always believed Panda is a combination of many many factors.
I don't think you take metrics and compare them between completely different sites. My thoughts were that Panda was a niche-based thing: your metrics are compared against those sites in a similar niche.
I have two such sites. One was smashed by Panda 1, while the other has never been touched. Both are in the blog/content space.
Site hit by Panda (SITE A):
Time on Page: 2:29
Site ignored by Panda (SITE B):
Time on Page: 2:18
Site A has far more broader and varied content. Site B has far more focused content within the niche. This explains some of the difference in bounce - users find similar things of interest in the narrow-focus site. Site A is far more difficult to integrate related content together.
Many of the search keywords for Site A tend to be asking a question. The user gets the answer (or not!) and leaves.
Site A also had lots of scrapers in it's pre-panda heyday. From the day Panda hit, the scrapers immediately outranked the original article (no matter what we tried - delaying RSS etc, DMCAs). This doesn't happen any more (probably due the low profile of the site, no-one is copying it).