Hi Alvin, Often, students get disengaged just for a short period, either from disinterest, being tired, not understanding, not prepared, or distracted by other thoughts. Sometimes this can be remedied by "techniques", such as breaking away for a few minutes and randomly asking questions of students, or even just circulating among the seats as class prgresses. These "mechanics" can assist the teacher getting the attention of students, then getting them refocused. As you say, discussion is a good way to bring students back on topic, too. Barry Westling