Jean Piaget, a Swiss psychologist and early childhood educator, made significant distributions to early childhood education developmental psychology especially in the areas of the developments of children's thought, cognition and language (Ornstein & Levine, 1993).
In his studies from 1920s to mid-1930s, he examined children's conceptions of moral judgement, number, space, logic, geometry, physical reality, reasoning and conception of the world (Egan, 1983).
PRINCIPLES OF LEARNING AND INSTRUCTION .
Piaget perceives the child as the primary agent. According to his cognitive theory, human behavior results from the adaptation of the agent to the environment as a consequence of a complex and continuous interaction between the two (Ornstein & Levine, 1993). The child 1- assimilates environmental factors; 2- adjusts to environmental requirements in order to be adapted to it. So, he learns to generalize, differentiate and coordinate the concepts of reality.
Piaget regards the human mind as an organism rather than as a mechanism (Egan, 1983). It is also possible to see this idea in his cognitive theory.
According to him intelligence develops in sequential stages consisting of specific periods. Each stage depends on the previous stage and leads to the next stage. The four stages identified by Piaget are given below:.
1- Sensorimotor stage.
2- Preoperational stage.
3- Concrete operations stage.
4- Formal operations stage.
In order to be able to understand his theory clearly, it is necessary to look at these stages in particular. Though his theory can be put into practice in many fields, we will only deal with the relationship between the stages and education (Piaget, 1952).
1. Sensorimotor Stage (0-2 years): .
This stage consists of six sub stages. These are: stage 1 (0- 1 month), stage 2 (1- 4 months), stage 3 (4- 8 months), stage 4 (8 -12 months), stage 5 (12- 18 months), stage 6 (18- 24 months). During the period from stage one to stage six the child undergoes some changes (Egan, 1983).