If You Can't Do...

During my many years as a student, I developed a theory concerning teaching. My experience on the other side of the pedagogical stick seems to rather have confirmed this suspicion:

The relationship between teaching aptitude and aggregate pupil performance is not linear, but rather a very shallow curve. In other words, while there may be a big difference in the performance of the pupils of a 1st percentile teacher and a 20th percentile teacher. The difference between, say, a 50th percentile and a 70th percentile teacher is MUCH smaller.

Once a teacher has a basic level of competence, the most he can ever hope to effect are the marginal cases. The good students will still be good students with a poor teacher, and bad students will still be bad students with a excellent teacher. I've seen several teachers enter the profession who have vague Stand-and-Deliver type dreams of making a difference, but it seems to me that these are almost certainly doomed to failure. (After all, Edward James Olmos' class consisted of self-selected students who wanted to take Calculus. Not random brothas from the barrio.)