AT KAIST, students give both midterm and final evaluations to their professors. The feedback can be used to determine whether a professor should keep their job or not. Given the high-stakes nature of this feedback data, it would stand to reason that the data collected be as accurate as possible. But what can really be measured halfway through a course and one week before final exams?
The first thing that can be measured is whether or not the students have been enjoying the course. The problem here is that different factors cause students to enjoy courses. A course might be fun because it is easy, or the students enjoy the topic, or the teacher is friendly or humorous. These factors are rarely explored when collecting student feedback.
The second thing that can be measured is how satisfied the students were with their scores and progress up to the feedback period. A student who bombed their midterm is unlikely to be "highly satisfied" with the course. Their frustration, while justifiable, may be misdirected. Once again, this cannot be established from most surveys.
A final thing that can be measured is the popularity of the teacher. Everyone has heard stories either firsthand or third-hand of teachers who give out candy or host pizza parties during the evaluation period. These teachers are often lauded by management as good examples but eyes roll when they are discussed by their colleagues. That being said, if they know how to game the rigged system then it is hard to fault them completely.
What cannot be measured, unfortunately, is whether or not the course and the information and experiences gleaned from it are of value to students after the course has ended. Students should be able to determine if the course being evaluated helped them in subsequent courses or after graduation before reporting on how effective the course and its teacher was.
I have been lucky enough to teach content courses during my time at KAIST and have met with students years after they took them. I am under no illusion that all of my students are completely satisfied with what they took away from my courses but after a few years I am much more sensitive regarding any feedback they want to share. After all, they now have a clearer picture of what I was trying to prepare them for.