At an abstract level, teaching a class can be perceived as one big regulation problem. For an optimal result, teachers must continuously (re)align their goals and sub-goals, and need to get timely and valid information on how they are doing in reaching these goals. This discussion describes the specific difficulties due to the time characteristics of the multiple, simultaneous events happening in classrooms, the lack of information on results, and the validity and usability of the shared knowledge-base. The contribution of the five articles in this special issue is discussed.