John,
The frustration you identified is all too common. Your list of 'elements' is a good one. The Student Preparedness is not often mentioned. That is a good description and it is very helpful. What would be the criteria (time, # of attempts, etc.) you would have the instructor use to indicate "how much effort" the teacher expects? I expect it would vary from activity to activity, course to course, and even teacher to teacher, but what are your primary criteria? Thanks for this helpful contribution.