For the first time ever, Google has released the full and complete version of the Search Quality Rating Guidelines that Search Quality Raters at Google use to rate the quality of the Google search results.
Google Hands Over The Key To Ranking?
Did Google just hand over the key to their ranking algorithm? No way. This is just a document used by consultants that help them rate the quality of the search results on Google.com and on Google's test servers. The algorithms don't read these guidelines. Although, it is a great way to get in the mindset of what types of pages Google wants to show in their search results. As most SEOs know, what Google wants in their search results are often not what Google gets in their search results. But in the best world, if your site meets all these requirements, and Google's algorithms were perfect, you should rank well. :)
John Mueller added on Google+:
As mentioned in the blog post, these are for evaluators who assess the quality of Google’s search results - give us feedback on our experiments. Ratings from evaluators do not determine individual site rankings, but are used help us understand our experiments. The evaluators base their ratings on guidelines we give them; the guidelines reflect what Google thinks search users want.
Google will be updating this document over time, so check back in, I'd say quarterly, to check updates.
Again, you can download the full 160-page PDF now - makes for excellent weekend reading.