Piaget had a background in both Biology and Philosophy and concepts from both these disciplines influences his theories and research of child development. The concept of cognitive structure is central to his theory. (来源：英语学习门户 http://www.EnglishCN.com)

　　Piaget's Model of Learning and Cognitive Development

　　Over a period of six decades, Jean Piaget conducted a program of naturalistic research that has profoundly affected our understanding of child development. Piaget called his general theoretical framework "genetic epistemology" because he was primarily interested in how knowledge developed in human organisms. Cognitive structures are patterns of physical or mental action that underlie specific acts of intelligence and correspond to stages of child development.

　　The learning process whereby this development takes place is a cycle of interaction between the individual and the environment. There are four primary cognitive development stages according to Piaget: sensorimotor, preoperations, concrete operation, and formal operation.

　　In the sensorimotor stage (0-2 years), the child is predominately concrete and active in his learning style. Yet the child has few schemes or theories into which he can assimilate events, and as a result, his primary stance toward the world is accommodative. Environment plays a major role in shaping his ideas and intentions. Learning occurs primarily through the association between stimulus and response.

David P.Ausubel（1918~ current）

　　David Paul Ausubel was born on October 25, 1918 in Brooklyn, New York.

　　What works in classrooms was the focus David Ausubel preferred for educational psychology. Ausubel’s research was built on the premise that new learning takes place most effectively when it fits into schemes that already exist in student’s minds. His advocacy of reception learning and expository teaching brought the expression “advance organizers” into the common vocabulary and practice of classroom teachers.

　　David P. Ausubel came to educational psychology from the field of medicine. He was an assistant surgeon and psychiatric resident with the U.S. Public Health Service and worked in Germany in the medical treatment of displaced persons immediately after World War II. After completing his training in psychiatry, Ausubel entered Columbia University and earned a Ph.D. in developmental psychology.

　　In 1950 Ausubel accepted a position with the Bureau of Educational Research at the University of Illinois. He remained with the Bureau for the next sixteen years. While Ausubel was at the University of Illinois, he published extensively on cognitive psychology. Ausubel left the University of Illinois in 1966 in order to accept a position with the Department of Applied Psychology, Ontario Institute of Studies in Education. He was in Toronto for two years, 1966-68. He moved to become Professor and Head of the Department of Educational Psychology, Graduate School and University of New York, where he served until his retirement in 1975. When Ausubel retired from university teaching, he returned to the practice of psychiatry at the Rockland Children’s Psychiatric Center.

　　David P. Ausubel (1918 - ) contributed much to cognitivelearning theory in his explaination of meaningful verbal learning which he sawas the predominant method of classroom learning.

　　To Ausubel, meaning was aphenomenon of consciousness and not of behavior. The external world acquiresmeaning when it is converted into the "content of consciousness." Hebelieved that a signifier (ie. word) has a meaning when its effect upon thelearner is equivalent to the effect of the object it signifies.

　　Bruner believedwhen there is "...some form of representational equivalence betweenlanguage (or symbols) and mental content," then there is meaning. Hebelieved there are two processes involved in cognitive learning: the receptionprocess and the discovery process. What he termed receptionprocesses are almost exclusively used in meaningful verbal learning. Concept formation and problem solving are more likely, according to Ausubel, toinvlove discovery processes.

　　Ausubel felt discovery learning techniques are often uneconomical,inefficient, and ineffective. He felt most school learning is verbal learning(receptive learning).

　　Subsequent research has shown that verbal learning is most effective forrapid learning and retention and that discovery learning is most effective infacilitating transfer.

　Claude Elwood.Shannon (1916-2001)

　　Claude Elwood Shannon was born in Petoskey, Michigan on April 30, 1916. He spent a productive 15 years at Bell Labs, working with such famous men as John Pierce, known for satellite communication; Harry Nyquist, with numerous contributions to signal theory; Hendrik Bode, who worked on feedback; and George Stibitz, who in 1938 built an early relay computer. Click here to learn more about his life and career.