Hi James: In some ways, no class is ever going to be the same in terms of delivery, resources, emphasis, or time spent on a topic, even though the exact content is being taught every session. This where the value of having pre-created back-up plans can be a real assistance to students. We have to assume students learn differently and at different paces. So being able to pull something from the treasury of instructional strategies to assist a student is needed. Better teachers prepare a whole bunch more than they ever have time for. Some of this can turned into back-up plans. Also, exercises, thought questions, or student-led explanations can be great methods to use as a back-up when there's just a few minutesleft in class. Regards, Barry