THE RECORDS OF 100 CONSECUTIVE CASES WERE STUDIED IN EACH GROUP OF DELINQUENT BOYS. WHILE THE PURPOSE OF THE ENTIRE SCHOOL IS TO MEET THE REHABILITATIVE AND TREATMENT NEEDS OF CHILDREN UNDER 16 REQUIRING RESIDENTIAL PLACEMENT, THE SECURITY WING WAS DESIGNED TO HOLD 'DIFFICULT, DANGEROUS AND DISRUPTIVE' BOYS WITH WHOM OTHER SCHOOLS COULD NOT COPE. JUVENILES IN THE CLOSED WING CAN BE ACCEPTED FROM 12.5 YEARS OF AGE WHILE THOSE IN THE OPEN SCHOOL ARE A LEAST 14 AND A HALF. THE AVERAGE LENGTH OF STAY IN RESIDENTIAL PLACEMENT IS 10 TO 11 MONTHS. MORE BOYS IN THE OPEN WING WERE COMMITTED THROUGH A SOCIAL WORK PROCEDURE OF HEARINGS DEALING WITH DELINQUENTS IN NEED OF TREATMENT, WHILE MORE BOYS IN THE SECURE WING CAME THROUGH JUVENILE COURTS. THE STUDY CONSIDERED SUCH SOCIOECONOMIC ASPECTS AS FAMILY CONDITIONS, DELINQUENT SIBLINGS, RELIGION, PARENTAL EMPLOYMENT, AND THE GEOGRAPHIC DISTRIBUTION OF CASES. THE BOYS THEMSELVES WERE STUDIED IN TERMS OF THEIR OFFENSES, PREVIOUS PLACEMENTS, AND RELATIONSHIPS WITH STAFF AND PEERS. IN ADDITION, A FOLLOWUP WAS DONE CONCERNING THE BOYS' SUBSEQUENT SCHOOL AND DELINQUENT CAREERS. RESULTS SHOWED THAT THE BOYS IN THE SECURITY WING WERE SIGNIFICANTLY DIFFERENT FROM THE OTHER GROUP WITH REGARD ONLY TO PREVIOUS COMMITTMENT IN INSTITUTIONS SUCH AS CHILDREN'S HOMES, HOSPITALS, FOSTER HOMES, ASSESSMENT CENTERS, AND EVEN PRISONS. PRIOR TO ENTRY IN THE SCHOOL STUDIES, BOTH GROUPS HAD A SIMILAR NUMBER OF THEFT OFFENSES (90 PERCENT). NO ONE IN EITHER GROUP HAD A RECORD OF SERIOUS OFFENSES SUCH AS MURDER OR MANSLAUGHTER. BOTH GROUPS CONTAINED A SMALL NUMBER OF BOYS COMMITTED FOR TRUANCY WITHOUT OFFENSE AND A FEW WHO WERE MENTALLY HANDICAPPED. THE REASON FOR COMMITMENT IN THE SECURITY WING WAS THE BOYS' PREVIOUS REFUSAL TO STAY IN CUSTODY AT OTHER OPEN INSTITUTIONS. THE GROUPS WERE VERY SIMILAR IN ALL OTHER RESPECTS, SUCH AS LOW SOCIOECONOMIC BACKGROUND, DISRUPTED FAMILIES, AVERAGE INTELLIGENCE, AND ACADEMIC UNDERACHIEVEMENT. THE FOLLOWUP SHOWED THAT ALMOST HALF OF THE BOYS FROM THE SECURITY WING WERE RECONVICTED WITHIN 2 MONTHS AFTER RELEASE, WHILE THOSE FROM THE OPEN SCHOOL REACHED THE SAME NUMBER OF RECONVICTIONS WITHIN 6 MONTHS. TABULAR DATA, FIGURES, A BIBLIOGRAPHY, AND AN INDEX ARE PROVIDED. (MRK)