You can read a lot about what search engineers want by looking at how the search results change. You can learn a bit more by listening to how they try to guide / influence / manipulate the market while engaging in discourse. And you can learn a lot more by reading their guidelines for how they expect people to rate search quality.
The reasons that the internal communication documents are so powerful are
they do not discuss search from “in an ideal world” approach, but cover the current marketplace from a pragmatic standpoint solving real issuesthe documents may display algorithmic holes that require manual interventionthe documents may show clues as to the hints search engineers give raters to quickly infer quality and relevancythe documents show issues or relevancy infractions that merit a lower relevancy ratingthe documents show how ratings change based on the quality and availability of information on the topichow something that is considered spam in some instances is considered fine if it is associated with a large well known brandhow things that are relevant in some verticals are irrelevant in others if Google runs a competing offeringthe current documents are the result of years of back and forth communication between quality raters and search engineers
Tags: Find, Google, Read, Relevant, Spam, Spying, This, What