CONTRARY TO THE EARLIER 'MEDICAL MODEL,' THE BEHAVIORAL APPROACH CONSIDERS DELINQUENCY AS A FAILURE TO LEARN APPROPRIATE SOCIAL BEHAVIOR; THE DELINQUENT MAY STILL BE REFORMED THROUGH THE REINFORCEMENT OF DESIRABLE PROSOCIAL BEHAVIOR. IN THIS CONTEXT, EARLIER INSTITUTIONAL PROGRAMS (SCHWITZGEBEL, 1964; SLACK, 1960) AS WELL AS MORE RECENT RESIDENTIAL AND NONRESIDENTIAL PROGRAMS (E.G., KENNEDY YOUTH CENTER, HAWAII YOUTH CORRECTION FACILITY) AND THESE PROGRAMS' PROCEDURES WERE REVIEWED. THE PROGRAM EVALUATIONS HELPED DETERMINE THE LONG-TERM TREATMENT EFFECTS, AND PROCEDURE EVALUATIONS WERE USEFUL IN MEASURING PROGRAM MODIFICATIONS AND SHORT-TERM EFFECTS. FOR INSTANCE, PRIOR TO IMPLEMENTING A NEW PROCEDURE, THE YOUTHS' BEHAVIOR WAS OBSERVED FOR SEVERAL DAYS TO DETERMINE A BASELINE. THE NEW TREATMENT PROCEDURE COULD THEN BE IMPLEMENTED WHILE CONCURRENT BEHAVIORAL CHANGES WERE MONITORED. AS A CONTROL, THE NEW PROCEDURE WAS HALTED AFTER SOME TIME, AND THE JUVENILES' BEHAVIOR WAS OBSERVED TO DISCOVER WHETHER IT FELL BACK TO THE BASE LINE. PROCEDURE EVALUATIONS WERE REVIEWED IN THE AREAS OF YOUTHS' SOCIAL BEHAVIOR, SELF-GOVERNMENT BEHAVIOR, ACADEMIC BEHAVIOR, VOCATIONAL BEHAVIOR, AND SELF-CARE BEHAVIOR. THESE REVIEWS INDICATED THAT (1) A WIDE RANGE OF BEHAVIORS HAS BEEN EFFECTIVELY MODIFIED; (2) MANY PROCEDURES HAVE EVOLVED INTO FULL-SCALE TREATMENT PROGRAMS IN SETTINGS THAT INCLUDE STATE INSTITUTIONS, AND RESIDENTIAL AND NONRESIDENTIAL COMMUNITY-BASED PROGRAMS; (3) THE EMPHASIS OF PROGRAMS AND EXPERIMENTS SEEMS TO BE CHANGING FROM CONTROL OF UNWANTED BEHAVIOR TO THE TEACHING OF DESIRABLE BEHAVIOR BY MEANS OF INSTRUCTION, PRACTICE, AND FEEDBACK; AND (4) THERE IS A NEED FOR BETTER TRAINED STAFF TO CARRY OUT MORE COMPLEX TEACHING PROCEDURES. THE ARTICLE INCLUDES EXTENSIVE REFERENCES.