RESEARCH IN WHICH BEHAVIOR THEORY WAS APPLIED TO TEACHING READING, WRITING, AND ARITHMETIC TO RETARDED CHILDREN IS REPORTED. TWENTY- SEVEN EDUCABLY RETARDED CHILDREN PARTICIPATED IN THE CORE GROUP. THE MEAN MENTAL AGE WAS 11 YEARS AND THE MEAN IQ WAS 63. IN AN EXPERIMENTAL ENVIRONMENT OF APPROVAL, ENCOURAGEMENT, AND TOKEN REINFORCEMENT, A MOTIVATIONAL SYSTEM FOR EACH CHILD GRADUALLY EMERGED TO PROMOTE COOPERATION, EFFECTIVE STUDY, AND INDEPENDENCE. PROGRAMED MATERIALS AND PROCEUDRES FOR READING, WRITING, AND ARITHMETIC WERE DESIGNED TO REWARD CORRECT RESPONSES WITH CANDY, TOYS, AND OUTINGS. CONTINUING REEVALUATION AND REVISION OF TEACHING MATERIALS, THE VARYING AND SHIFTING OF SCHEDULES OF REINFORCEMENT, AND THE SIZE OF WORK UNITS DERIVED FROM ACTUAL CHILD PERFORMANCE PLAYED A CENTRAL ROLE IN TASKS INVOLVING SERIAL LEARNING. THE PROGRAMS ARE BEING REVISED, REFINED, AND EXTENDED THROUGH CONTINUING RESEARCH. (MC)