I have 53 students in my class right now. A 15-minute oral exam works out to 13.25 hours of exam time, assuming perfect efficiency. As a comparison, our in-clas

I have 53 students in my class right now. A 15-minute oral exam works out to 13.25 hours of exam time, assuming perfect efficiency. As a comparison, our in-class time (3 hours over 16 weeks) works out to only about 48 hours. So a single oral exam works out to 1/4th of all class time. But in principle this is not a problem for me, I already spend at least this much time grading papers, and an oral exam would be much more pleasant. The real problems will come up when (1) students are forced to schedule these 15-minute slots, and (2) they complain about the lack of time and non-objective grading rubric.