Evaluations of PSI (Personalized System of Instruction)
courses typically lack a follow-up study beyond the first
year. So it is difficult to determine how much of the students' reaction arises from the experimental nature of the format (the " Hawthorne effect") and how much can be
attributed to PSI itself. We decided to investigate this
question by distributing the same questionnaire to students
in the PSI section of Natural Sciences 9 ("The Astronomical
Perspective") at Harvard University over a seven semester period (including summers). In addition, we wanted to see if the initial positive response continued when later instructors (R.J .B. and others) taught it after its originator (M.Z.), with little or no supervision from
him.
