Some Perils of P.S.I. and How to Avoid Them The Kellerl or P.S.I. approach to Learning has achieved wide publicity and success in recent years. We began development of a self-paced approach to freshman chemistry with a test program which was offered to a small class during a 12-week extension course. Our approach revealed weaknesses in our method which should he avoided by anyone attempting P.S.I. Method
Only two paints should he noted in connection with the method used: (1) Students could obtain a guaranteed mark based on their performance in unit tests. (2) The students backgrounds were too varied and too weak to allow meaningful pre-testing.
Results
Student X
Exam Mark
Guranteed Mark
60 40 34 78 52 44 58 32 78 40 68
50 50 0 80 50 50 0 50 80 50 50
60 50 34 80 52 50
48
50
50
1. P h y s E d teacher 2. E x Nurse 3. Student 4. English major 5. Housewife 6. Student 7. ? 8. Student 9. Linguist 10. Nurse 11. High School teacher 12. Musician
Mark Awarded
58
50 80 50 70
Student X
Exam Mark
Guaranteed Mark
Mark Awarded
13. Grade 12 student 46 50 50 14. Salesman 56 80 80 15. Grade 12 56 50 56 16. Elem. School 44 50 50 teacher 17. Hockey player ill 80 80 18. M.Sc. (math) ill 80 80 19. illa 20. Dropped course for personal reasons 21. Dropped course for personal reasons ' Average 52.13 49.38 57.50
* This student suffered severe family problems during t h e course and wrote a deferred examination. is n o t considered in this report though h e failed t h e course.
He
The results are shown in the accompanyingtable which is self-explanatory. The Keller or P.S.I. approach is a valuable and flexible tool2 hut caution is important for the neophyte. Same rules have been suggested by other authors.3 The fallowing are the result of the present work: 1) Unit tests must he sufficiently difficult to challenge the student. Failure to do so results in a student progressing without true mastery of the material. 2) Unit tests must include a strong review component. This ensures the course will be seen as a continuous whole rather than a set of isolated concepts. prejudice.) This 3) A final examination should he inciuded. (The weight of such an exam is a matter of is vital to any internal assessment of the course. 4) Adequate time must he allowed for completion of the course material. Perhaps the concept of self-pacing cannot he meaningful in a 12-week course. 5) Extravagant results (i.e., first-class standing for the majority of students) cannot he reasonably expected from very weak and heterogeneousclasses. The authors wish to acknowledge the self-sacrificingwork of L. Dickie and J. Mertens who acted as undergraduate nroctors for this work and Ann Sunahara who conducted the laboratory portion of the course. 'Lewis, D. K., and Wolf, W. A., J. CHEM. EDUC., 50,51 (1973). ZAs a result of this experience, this method has been successfully employed by us with a freshman class of 160 students. ZGreen, Jr., Ben A,, "Fifteen Reasons Not to Use the Keller Plan" "P.S.I., 41 Germinal Papers," (Editor: Sherman, J. Gilmore) W. A. Benjamin, Inc. University of Western Ontario London, Ontario, Canada
584 / Journal of Chemical Education
Ronald R. Martin Kam Srikarneswaran
