The calculus reform died without anybody noticing it and, that I know of, there were no longitudinal studies. In one case, though, if not an a longitudinal study, there was an evaluation and what followed was interesting.
In 1988, I was the principal investigator of a small NSF calculus grant predicated on two ideas:
- The very length of the standard Pecalculus 1 - Precalculus 2 - Calculus 1 sequence is of and by itself a major problem.
- The content of the sequence would be integrated in a two-semester sequence by way of a systematic use of polynomial approximations.
After a few years, in the words of the school's Office of Institutional Research, it was established that
Of those attempting the first course in each sequence, 12.5% finished
the [conventional three semester 10 hour] sequence while 48.3%
finished the [integrated two semester 8-hour] sequence, revealing a
definite association between the [integrated two semester 8 hour]
sequence and completion (chi2(1) = 82.14, p < .001).
Furthermore, the study mentioned that the same number of students in both sequences passed Calculus 2 but that the numbers in both sequences were too small to be meaningful.
So what happened next? The integrated sequence died within the next few years and no one was talking.
And then, a few years later, the school did a longitudinal study of the entire Arithmetic - Basic Algebra - Intermediate Algebra - Precalculus 1 - Precalculus 2 - Calculus 1 sequence. And, here again, the rather dismal evidence was immediately forgotten.