[crpatino]

> I think student, ... happiness should be one of the key metrics

I have seen it first hand. Students are always happiest when a charming instructor provides bland infotainment that allows them to sustain a pretense of high achievement without trying very hard. The second hapiest students are those of mediocre teachers who give good grades to everyone so no one is very motivated to rock the boat. As a matter of fact, the teacher has to descend pretty low in terms of incompetence so the students will actually be less happy than if presented with a lecturer that knows their subject and expects them to put an actual effort in learning.

Of course, all things being equal, stern lecturers are more disliked than more relaxed instructors. This is not what I am taking about.