Stelian,
I make my pretests using the course objectives, and put emphasis on the topics, "they absolutely have to know these" before they leave my class. Then I make my pretest around these "must know" categories. If students are mostly proficient with one or two of the topics, I will plan to spend less time on those, and redistribute time to other must know topics. So, really, it's a planning tool for me.
Barry Westling
