In the absence of that paper, the only related thing I'm familiar with that claims a basis in evidence is Spolsky's [Hitting The High Notes][1]. The hypothesis

In the absence of that paper, the only related thing I'm familiar with that claims a basis in evidence is Spolsky's [Hitting The High Notes][1]. The hypothesis there was that time spent on assignments and grade obtained are two essentially independent variables. [1] http://www.joelonsoftware.com/articles/HighNotes.html http://www.joelonsoftware.com/articles/HighNotes.html