This is a teaching suggestion I found in this paper:
David S. Moore (1993) “A Generation of Statistics Education: An Interview with Frederick Mosteller”, Journal of Statistics Education, 1:1, DOI: 10.1080/10691898.1993.11910453
I quoted from the paper in my previous post.
The suggestion is - ask the students what part of the lecture was “muddiest”:
I learned that certain professors used a device which was called the “minute paper.” The word “minute” expresses the idea that something is done in a very short time. The idea of the professor who used it first was that he just wanted to find out what the students wanted to know and what they were having trouble with. So I thought that I would try it out. In the last 2 or 3 minutes of the class, I would ask the students to write down what was the most important thing in the lesson and what they’d like to know more about.
…
I said to the class “Now we’ve done this for a week, and [the resulting feedback] seems pretty bland to me. What is the matter with it?” One student said it was very simple: I wasn’t getting any feedback because I was asking them what was the most important point of the class and I’d already written on the board at the beginning of class the four main points in the lecture. I was not likely to get anything much different from what I wrote down, and what the students wanted to know more about was bound to be more about how to do whatever it was that we’d just done. I wasn’t learning much from the minute papers, so I was impressed by this remark. This kid had seen through the whole process.
So I said maybe we should have some other kind of question, like “What is the muddiest point in the lecture?” The students erupted with applause, and from then on that was the question at the end of the hour. We still also ask them what they want to know more about.