Opinions about theory of jean Piaget t "Cognitive development":
"Piaget (1972) believes that children's thinking develops according to the stages or period-the period of the growing complex. According to Piaget's theory of stages, each individual will go through a series of qualitative changes that are invariant, is always fixed, not jump or go back. This qualitative change occurs because the biological pressure to adjust to the environment as well as the organizing structure of thinking. To demonstrate the cognitive structure underlying patterns of behavior that is organized, Piaget used the term schema and adaptation ".