The only kind of search result that you get from Spock is a list of people; and it interprets any query as if it is about people. So whether you search for democrats or ruby on rails or new york, the results will be lists of people associated with the query. In that sense, the algorithm is probably a flavor of the page rank or frequency analysis algorithm used by Google – but tailored to people.
Read Alex Iksold’s full review of Spock: Spock: Vertical Search Done Right