Most interesting bit-- from Rana's comment:
At another place I worked, there was this very odd curve that kept showing up in my classes (so I know it wasn’t just one anomalous class). Basically, instead of there being something bell-like, there was this odd bulge at the B+ side and no A-s, and then a sharp spike of As.
For me, A-range work tends to combine originality with a firm grasp of technical skills. B-range tends to lack originality while being technically sound, or vice versa. C-range reveals a lack of understanding of the assignment, or an inability to meet much more than the basic requirements. D-range means something went noticeably wrong; Fs are just flat out failures. I don’t give many Fs, and I don’t give very many As, either. But, as I tell the students, this is because of the way student skills, interest, etc. average out; if everyone one day did A (or F) work, then that’s what everyone gets.
Anyway, what I finally figured out was happening with that peculiar curve was this: the students in that B+ lump had the technical skills to do A level work, and many of them were capable of the sort of originality and insight that characterizes A level work - but they were holding that back. They had such an ingrained respect for authority that they did not believe it was appropriate, or their place, to insert any of their own ideas into the work. Rather, they believed that they were to do a good job re-presenting the things they had learned in lectures and in the readings.
Once I realized this, and started aggressively encouraging them to offer their own insights on the material, there was a sudden spike in A-level papers and the bulge went away.