Certainly, although you have to differentiate between confusion, which can be beneficial as you say, and being completely lost, which hampers learning. The sub

Certainly, although you have to differentiate between confusion, which can be beneficial as you say, and being completely lost, which hampers learning. The subject matter being obvious and well understood can look a lot like the subject matter having no meaning at all because the learners are completely lost. Particularly, asking 'any questions?' and then moving on (often rapidly) when no questions are forthcoming is another sign. It's hard to tell if it is because there is full understanding or almost no understanding. Instead, try giving more time for people to think of questions, and ask 'what questions do you have?'. I've not had a chance to try, but in a similar vein, having an IRC chat running along side a lecture could provide similar useful feedback, and an avenue for questions without making learners feel stupid. I like the direction they are taking with this tool. Good, honest, and especially timely feedback is one of the difficult challenges of education. Without it you are flying blind.