tedster - 5:55 pm on Nov 10, 2011 (gmt 0)
Google uses the manual to train employees how to rate websites.
These clarifications came from Matt Cutts at the Monday night Pubcon networking event:
Webmasters tend to put a slightly skewed angle on this. The quality raters are actually rating a SERP (that is, a particular algo configuration) as a quality control measure for the algo team. Their ratings do not directly change rankings- but they hep the algo team see if the algo worked as planned or not.
Also, note that this document is not for the spam team. They also have a training document and use human quality raters - but that document has never been leaked.