This report outlines the use of Keller's Personalized
System of Instruction (PSI) format for some of the
students enrolled in an astronomy course for non-science
specialists at Harvard University. The students in the
PSI section perceived the unit tests and their immediate
correction by the instructor as the most important component in their learning, and they felt strongly positive about the structured student-teacher interaction. In comparison with the student in the traditionally taught
sections, the PSI students did master the material somewhat
better as measured by a common final exam. The students' perceptions of PSI' s educational merits guided the instructor in isolating some of the potentials and problems with PSI.
