Inspired by the Just-in-time-teaching literature, I use a feedback loop based on the Just-in-time-teaching literature, which allows students to submit both "muddling" questions about fundamental concepts they are struggling to understand, and "deepening" questions, which are meant to stimulate further discussions. I have found this particularly useful in larger classes, as it allows students an equal chance to ask questions regardless of their academic level. Below is an example of instructions to students (in Swedish).