<p>I had a grad student instructor once…for a class I took at UMass. I guess that doesn’t count. 
(And I knew it was going to be taught by a grad student going in, as it was a class UMass had 10 sections of while Smith had just the one and I wanted to take three classes that were offered in two time slots at Smith, so I had to go off campus for one of them.)</p>
<p>However, I did take a class taught by a tenured Smith professor who frequently canceled class (by the end of the course it had averaged to at least once a week for a class that was supposed to meet three times a week) and she didn’t make it up but still expected us to understand the material as if she did hold class every day it was scheduled. It was a pretty horrible experience.</p>