His grading procedure was simple: on the final day of class he would bring in his bathroom scale and weigh the work of the "quantity" group: fifty pounds of pots rated an "A", forty pounds a "B", and so on. Those being graded on "quality", however, needed to produce only one pot - albeit a perfect one - to get an "A".
When the class came to an end and when the grading began and a curious fact emerged: the works of the highest quality were all produced by the group being graded for quantity.
It seems that while the "quantity" group was busily churning out piles of work - and learning from their mistakes - the "quality" group had sat theorizing about perfection, and in the end had little more to show for their efforts than grandiose theories and a pile of dead clay.
[This little anecdote is attributed to David Bayles and Ted Orland and I'm not sure of much more than that.]