A Piagetian preschool emphasizes the child's active construction of mental images rather than passive association of words and pictures with real objects. The role of the teacher is neither to dictate good behavior nor to transmit ready-made predigested knowledge. Her role is to help the child to control his own behavior and to find things out as a result of his own curiosity and exploration. The child builds knowledge through his own actions on objects, using object feedback and his own reasoning processes. To accomplish this task, the teacher selects a variety of objects to give a range of possible activities from which the child can choose. The teacher diagnostically picks up on the child's interests by making suggestions and asking questions. Piaget's distinction among physical, social, and logico-mathematical knowledge and representation guides the teacher in deciding when to answer a child's specific questions and when to leave the question open for the child to find the answer. The basic principle to keep in mind is that play is the most powerful ally on the teacher's side. A curriculum which reflects an understanding of the nature of intelligence from Piaget's biological perspective will define its long-term goals first and then proceed to conceptualize its short-term goals. (Author/WY)