What are some of the metrics that Google uses to evaluate whether one iteration of the ranking algorithm is delivering better quality results to users than another?



Learn more about search evaluation at Google:
http://googleblog.blogspot.com/2008/09/search-evaluation-at-google.html
http://www.google.com/insidesearch/howsearchworks/algorithms.html

Have a question? Ask it in their Webmaster Help Forum:
https://productforums.google.com/forum/#!forum/webmasters
Want your question to be answered on a video like this? Follow Google Webmaster on Twitter and look for an announcement when we take new questions:
http://twitter.com/googlewmc

More videos: https://www.youtube.com/user/GoogleWebmasterHelp
Webmaster Central Blog: http://googlewebmastercentral.blogspot.com/
Webmaster Central: http://www.google.com/webmasters/