Ideally, we would have liked to run a similar experiment that compares two
batches of Fall semester students in Calculus-I. Due to certain limitations, this
was not possible. In particular, the review modules were in the piloting phase
in the Calculus-I courses during Fall 2011 and have been part of the syllabus
ever since then. For Fall semesters prior to 2011, online homework (the source
of our control data) was not a course component.