JonW - 4:45 am on Apr 26, 2011 (gmt 0)

Ok. I see. Even quality sites show that option.

I'd guess that the UI data is separate from the algorithm, though the algorithm likely includes info on the distribution of time on page. I'm less worried then because the algorithim used lots the information to make a determination, a increase PR by one, could well ofset even a poor time on page factor....