Hi Joseph:
Pretesting can be a helpful tool. It takes some prep time, and course time away from other activities, but when I don't how much my students know, or when they're just beginning, that's a good time to do pretesting.
Also, it doesn't have to be an exhaustive pretest. Sometimes, just 2-3 questions is all that is needed to determine where the emphasis of the topic will be.
Regards, Barry
