Stage theory_of_cognitive development was introduced by child psychologist Jean Piaget in 19s. This theory describes cognitive development in context of age.

Piaget has divided human cognitive development in four stages: sensorimotor, preoperational, concrete, and formal, as they are described below.

• Sensorimotor stage (birth to 2 years): In this stage cognitive system of an infant is limited to motor reflexes, but also some more complex procedures built on those reflexes. Infant interacts with the environment and learns to understand the world. Learning takes place through absorbing into the existing schema and accommodating when schemata change is required.
• Preoperational stage (2 to 6/7 years): Children now develop language and mental imagery skills, but still cannot conceptualize abstractly and don't have sense of time. A child can now think about events and things that aren't present in the moment of speaking. He can see the world only from his perspective and assumes other do so as well. Teaching a child in this stage must take into account his not fully understand concepts of time phenomenon.
• Concrete operations (6/7 to 11/12 years): Children in this stage of development are able to analyze more perspectives simultaneously. Much of learning if performed through assimilation. Although they can understand concrete problems, according to Piaget they still cannot analyze abstract problems and all of their logical consequences.
• Formal operations (11/12 to adolescence) : Piaget claims that the final form of cognition is reached in this stage. Abstract thinking capabilities in this stage are very similar to ones of adults. individual at this stage is also capable of hypothetical and deductive reasoning. This is supposed to be the final stage of cognitive development and although the knowledge base of an individual is still to be expanded, his thinking capabilities are now as strong as they would get.

• Teaching an infant in this stage should be orientated on its sensorimotor system.
• Children can now actively engage in learning and exploring.
• Learning in this stage is facilitated through an opportunity to ask questions and get explanations which allow learner to mentally mentally manipulate information.
• Teaching for the adolescent may be wideranging because he'll be able to consider many possibilities from several perspectives.

Redes de Computadores e suas aplicações na Educação - Piaget's Stage Theory of Development.

University of Hawaii - Honululu Community Coledge - PIAGET'S COGNITIVE STAGES.

Stage Theory of Cognitive Development (Piaget) at Learning Theories.