A Dutch secondary classroom with a board, a wall clock and twelve students. In each of four lesson moments, one or two named students show observable behaviour (fidgeting with a switch, copying instead of wiring, a worksheet with a coherent wrong method, erasing, arriving late and loud). The visitor names each barrier, then chooses one move and sees the students’ posture and the lesson clock respond. Every decision in this scene can also be made with the buttons in the controls panel.
