Piaget's idea was that adults did not simply know more than children, but that their knowledge was structured differently. Indeed, Piaget suggested that children at different stages of their development thought about and interpreted their worlds in different ways. Piaget developed the idea of children as ' "little scientists" who were engaged in active exploration, seeking understanding and knowledge' (Bee, 164).
Piaget's theory of cognitive development was based on three main principles - those of assimilation, accommodation and equilibration. These will be explained below; however, first it is important to define the term 'schema'. Schema is a cognitive representation of activities or things. When a baby is born it will have an innate schema for sucking in order to ensure that it can feed and therefore grow. As the baby grows, this schema will become integrated with other feeding schemas as the baby's experience and nutrition changes.
Assimilation is the process of putting a new experience into already existing mental structure. Children develop cognitive structures to help them make sense of their world and when they encounter a new experience they place this into the schemas they have already developed. The process of assimilation is an active one. Children are not merely absorbing knowledge via a process of osmosis, they are actively engaged in the assimilation process. They are active insofar as they are selective - they do not absorb all the information they encounter.
Accommodation is the revising of an existing schema due to a new experience. For example, a child may have a schema that describes all flying objects as birds, but when he encounters a Frisbee this does not fit the schema. It isn't alive; therefore a new schema is necessary. As children develop they will encounter experiences which their existing schemas are incapable of explaining. Therefore they must develop new schemas in response to new experiences.
Equilibration is the process of seeking to achieve cognitive stability through assimilation and accommodation. The child is constantly trying to interpret and understand the world while encountering new experiences. The child builds an understanding of the world and how it works, but this is constantly challenged by new experiences that conflict with their current understanding. They seek to develop schemas to help this interpretation process. The drive for equilibrium is that all these interpretations and schemas fit together and make a general picture of the world that is logical. However, equilibrium is a constantly changing thing, as each time a child encounters a new experience they are in a place of disequilibrium until assimilation or accommodation has taken place. If we return to the example of the Frisbee, when the child first encounters it they are in a state of confusion (i.e. not equilibrium) - 'It isn't alive, I can't explain it with my present schemas or ways of thinking'. Through accommodation and the development of new schemas the child returns to a state of equilibrium, until the next new experience.
Piaget's Stage Model of Cognitive Development
Piaget suggested that the child's cognitive development could be divided into stages. As the child develops and goes