gouri - 2:26 am on Jul 10, 2012 (gmt 0)

If you're used to the old school SEO approach - where you make changes and inch your way up the rankings, tracking what specific changes had what effect - then you may be out of luck today. It still seems to work a little bit like that right now, but not really all that much any more. Google uses statistical sampling, and we are pretty much in the same boat - we've got to look at the big sweep of things.

@tedster,

When you say statistical sampling, does that mean looking at the user engagement of websites and using that as a ranking factor, instead of just the technical aspects.