How does Google use human raters in web search?

Can you provide more details on how Google uses 'human raters' as part of their algorithm? AJ Kohn, SF, CA Read more about search evaluation at Google: http://googleblog.blogspot.com/2008/09/search-evaluation-at-google.html Have a question? Ask it in our Webmaster Help Forum: http://productforums.google.com/forum/#!forum/webmasters Want your question to be answered on a video like this? Follow us on Twitter and look for an announcement when we take new questions: http://twitter.com/googlewmc More videos: http://www.youtube.com/GoogleWebmasterHelp Webmaster Central Blog: http://googlewebmastercentral.blogspot.com/ Webmaster Central: http://www.google.com/webmasters