Yesterday, during some idle time in the office, a colleague of mine has discovered that I am currently ranked at position 20 worldwide by Microsoft Academic Search for my subfield regarding the last 5 year impact. While certainly flattering, this ranking is also quite clearly bogus, as many much more eminent academics are ranked far behind me in this list.
The Occam's razor explanation that there simply is another researcher of my name in my field can be discarded, as Microsoft Academic profile does indeed list my, and only my, publications (as well as a profile pic that they seem to have grabbed from an old university web page).
So my question is the following: how does Microsoft Academic Search actually generate rankings (of individual academics, but there are also rankings of journals)? It seems clear that not all citations and publications are considered equal (otherwise I would not end up so far to the front with a comparatively meager set of papers and citations), but how do they decide what is "worth" how much?
I am mostly looking for answers that refer to papers or web links coming from MS insiders on their ranking algorithms. Barring that, some well thought-through speculation from outsiders is also ok :)
I just discovered that Microsoft Academic Search seems to employ the notion of a field rating for conferences and journals, and the rating for some of the venues that we prefer seems to be unreasonably high. However, that still does not fully explain my curious case (and it still leaves open the question of how these field ratings are generated in the first place).