B.F. Skinner presented a formulation of operant behavior and a method for its investigation that are basic to the analysis of behavior now practiced in hundreds of laboratories throughout the world. For this work, Dr. Skinner was given teh National Medal of Science by President Lyndon Johnson and the Gold Medal of the American Psychological Foundation. Many practical applications of the method have been made in other sciences, such as physciology and psycho-pharmacology. The principles of operant conditioning led to programmed instruction and the modern conception of teaching machines, for which Dr. Skinner received many awards from educational organizations. He was also responsible for the first research in what has come to be called behavior therapy.