Had coffee this morning with a colleague and we got to talking about how encyclopedic, informative type sites often end up with a natural mix of "fat" and "thin" pages. eg.. a destination guide might have 300 pages, with the capital cities and tourist hot-spot pages being full of good "fat" stuff but regions off the beaten trail are "thin" by comparison because there just isn't much to say. That's just the way it is.
There is nothing wrong with these pages and they might still be the best information source available... but they are "thin" when compared to the rest of the site. (Fewer visitors, less time on page etc)
Is it possible that sites with a pronounced variation in "fat" vs "thin" pages might be on Panda's radar? From a human perspective, we can look at pages and say they are not "thin" because of what we see..... whereas an algo might see a ratio of "fat" vs "thin" that triggers a bad site slap.
Lots of folks are/have been complaining about sites of lesser quality now starting to dominate their serps..... and I have to agree. The sites I'm seeing are mostly bland, under researched, lacking in substance, with a templated format and certainly not the best resource available.
Could it be that sites are escaping Panda, not by the quality they deliver, but by having a "fat" vs "thin" ratio that keeps them below some magic threshold?.... and conversely, real quality sites are being hit because there is too big a difference between their key pages and the rest?