Hi Frederick: I have found my students get used to taking a brief pretest when I start a new unit. They have learned that it may contain keys to the quizzes and tests they'll be taking at some point. Some even rely on their non-graded pretest for studying. Afterall, I am assessing what is known about a subject so I can be sure I cover essential material thoroughly. That said, I can say I don't pretest every topic, or even every course. It depends on the particular cohort I'm teaching with at the time. Regards, Barry