On 1st March 2013, Google finally unveiled its search quality rating guidelines publicly. As a part of How Search Works interactive info graphic
, Google presented this 43 page document to the world.
The document leaked in 2001, 2008, 2012, and several other times, after which Google’s representatives, said they were considering publicizing this document and finally, they have.
Search quality raters hired by Google to ensure quality of search results, utilize these guidelines.
What do these search quality raters do? Well, they are third party people hired by Google to take care of the quality of search results, rather than rank them.
So, for people who are willing to brush up their knowledge Google has given them plenty to read.