Judith,
Yeah, there are a lot of dynamics at play here. For me, I find what's most helpful is to be able to make (relatively minor) adjustments in what I had planned in order to meet the needs of the consensus of the class, based on the results of the pretesting. Also, I don't pre test all the time, just at times when I have no idea where the general level of prior learning is at.
Barry Westling
