The philosophy underlying the African Primary Science Program, according to the author, is that the essence of science is not merely the statement of principles; it involves the struggle to find out about the material world. This program sought to develop the intellectual alertness of the children, and improve their questioning, and problem solving processes. Anecdotes describing learning activities characteristic of this program are presented, as well as a brief description of its development and underlying philosophy. The curriculum was evaluated by comparing the performance of experimental classes and non-exposed classes on a variety of tasks using manipulative materials; the observation procedures are described in detail. The results are summarized in terms of task performance, student behavior, and development of students' potential. The appendices guidelines for evaluating a child's day-to-day progress; ways to find out from teachers whether or not the unit is working; hints for writing science units; a discussion of concepts; a brief account of problem solving tasks presented in two Massachusetts fifth grade classes; and a 93-item bibliography. (GDC)