Kurt,
Does that mean that you normalize the students to a standard bell curve or does that just mean if they do average work, average is a C, work beyond average will be a B and work that is truly outstanding and well above and beyond normal is an A? If all the students really did outstanding work, they would still all get A's correct. We all struggle with this, I believe. I feel I have high standards and I learn toward a "C" is average work, or met the basic expectations. Going beyond the basic expectation then gets in to the B and A range. If you don't get even the minimum....well you know.
Herbert Brown III