Bill Slawski covered a recently awarded patent from Google written by April R. Lehman and the famous Navneet Panda (from the Panda algorithm) named Site quality score.
The patent was filed back in 2012 but was just recently awarded to Google. So it may be currently baked into the algorithm or it may not be used at all. :)
But check it out:
Methods, systems, and apparatus, including computer programs encoded on computer storage media, for determining a first count of unique queries, received by a search engine, that are categorized as referring to a particular site; determining a second count of unique queries, received by the search engine, that are associated with the particular site, wherein a query is associated with the particular site when the query is followed by a user selection of a search result that (a) was presented, by the search engine, in response to the query and (b) identifies a resource in the particular site; and determining, based on the first and second counts, a site quality score for the particular site.
I am no PhD but it seems like the more a searcher specifically searches for a specific site with a query, maybe using a site command or site name in the query, with a keyword, the more Google may trust that site as a quality site on that topic? Of course, this is easily spammable, so I doubt it is that simple or even if it is used but if you dig into the patent, it shows you how Navneet Panda thinks about quality, which is what the Panda algorithm is all about.
Forum discussion at WebmasterWorld.
