The educational experiment reported here was based on the premise that frequent testing should motivate students to repetitive and intensive study habits; as a consequence they should perform better.

The Keller1 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 be avoided by anyone attempting P.S.I. MethodOnly two points should be 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.