Jean Piaget was a Swiss psychologist who began the systematic study of children's behavior in the 1920s. And even though Piaget's teachings have had a dramatic effect on educational theory, his focus was not on education but on the development of intelligence. Piaget described and elaborated the following basic concepts:

  • All children, beginning from infancy, pass through an orderly succession of developmental stages and substages. Their current stage of development determines the way they interpret experiences, structure problems, and seek solutions.
  • The infant is in the sensorimotor stage of development. He understands the world by the actions he performs. The preschool child is in the preoperational stage of development. In contrast to the infant, the preschool child recognizes that objects exist even when he does not touch them. The preschooler has developed his own system of symbols (images, props, and words) to represent objects in the real world.
  • Learning takes place by the processes of assimilation and accommodation. When a child is introduced to a new phenomenon, she tries to understand it by assimilating it, or associating it with things that she already knows. As the child gains experience with the new phenomenon, her way of thinking changes, or accommodates, to take into account the characteristics of the new phenomenon. This implies that children should be introduced to new experiences that are related to experiences they have already had but that also challenge their thinking in some way.
  • Children are innately curious and motivated to learn, whether or not they receive external rewards and encouragement.

Based on this system of beliefs, preschools that ascribe to the Piagetian philosophy carry out the following practices:

  • The teacher is seen as a facilitator. She arranges the environment and prepares activities and experiences appropriate to the developmental level of the children in the class.
  • Recognizing that the child learns by actively organizing and constructing the environment, the teacher provides real materials for the child to sort, order, and arrange.
  • Concrete experiences are introduced before abstract concepts. For example, a child is given ample experience with objects floating and sinking before being taught scientific concepts such as density and displacement.
  • Imaginative play is encouraged. Pretending is viewed as a way of developing a system of symbols to stand for real events and as a way of learning to take different points of view.
  • The child is given many opportunities to experiment with different media, including water, sand, paint, clay, and play dough. Through manipulation, the child will make her own discoveries about the nature of reality.
  • No external rewards are offered for the accomplishment of a task, and children are permitted to make choices about what they are going to do.
  • Repetition of a task is encouraged, if this is what the child wants.