Piaget's concepts of knowledge seen as a result of active interaction between the child and his environment, and motivation, seen as intrinsic to intellectual functioning, have implications for the development of preschool programs. A preschool program must be action-oriented if the child is to learn to "know" and must offer an environmental setting that facilitates the modification of intelligence. The particular characteristics of preoperational children make them especially attuned to the use of the following conditions and materials in preschool programs: (1) the use of materials that help the child build feelings of competency and that center on him; (2) opportunities and time for the child to repeat actions meaningful to him and to order his actions within an environment complex enough to make intellectual demands upon him; (3) provision for play wherein he may adapt his play to satisfy his purposes; (4) materials used to represent the child's concrete experiences-wood, clay, music, reading aloud; and (5) provision for functional situations wherein he can engage in a range of mental actions. (KM)