Panda Metric : Google Usage of User Engagement Metrics

I am continually surprised at some in the community that point to a couple of individual metrics as ‘the ones’ that caused xyz to happen in the most recent update. I think it is time to look at the greater picture of data that Google has available.Eric Enge had a presentation at PubCon Austin that he felt Panda pumped up 20% user engagment metrics into the algo. It really got me thinking about this aspect indepth. I started to put together a list of possible data sources google could use as metrics (signals), and I was pretty surprised at how large a list it became with very little effort.