THE STUDY SAMPLE INCLUDED 248 DELINQUENTS, AGE 10 TO 17, UNDER THE SUPERVISION OF THE ST. L0UIS JUVENILE COURT IN 1972, THEIR PARENTS, AND 15 PROBATION OFFICERS. SUBJECTS WERE ASKED ABOUT THEIR PERCEPTIONS OF JUVENILE COURT SUPERVISION--THE PROBATION OFFICER'S FUNCTIONS, PROBATION PROGRAM OPERATIONS AND EFFECTIVENESS. PROBATION EFFECTIVENESS WAS ASSESSED IN TERMS OF RECIDIVISM AND SCHOOL REPORTS ON ATTENDANCE, BEHAVIOR, AND GRADES. THE YOUTHS, THEIR PARENTS, AND THE PROBATION OFFICERS TENDED TO AGREE ON THE NATURE AND RELATIVE IMPORTANCE OF OFFICERS' FUNCTIONS. PERCEPTIONS OF AN OFFICER'S ABILITY TO HELP WITH A CHILD'S PROBLEMS WERE NOT RELATED TO CASE OUTCOME. ASKED ABOUT THE EFFECT OF THE OFFICER ON THE CHILD, OFFICERS AND JUVENILES SELECTED 'NO EFFECT,' FOLLOWED BY 'BEHAVIOR'; PARENTS SPECIFIED THE SAME EFFECTS, BUT IN THE REVERSE ORDER. PARENTS AND JUVENILES THOUGHT THE OFFICERS HELPED CHILDREN WITH THEIR PROBLEMS THROUGH BOTH CONTROL AND CHANGE, WHEREAS OFFICERS TENDED TO SEE THEMSELVES AS AGENTS OF CONTROL ONLY. SHARED ASSESSMENTS OF THE RESULTS OF SUPERVISION (GOOD, FAIR, POOR) OCCURRED IN UNSUCCESSFUL CASES BUT NOT IN SUCCESSFUL CASES. PARENTS AND CHILDREN HAD FEW UNMET EXPECTATIONS IN SUPERVISION, REGARDLESS OF CASE OUTCOME. THERE WAS NO RELATIONSHIP BETWEEN THE NUMBER OF PRACTICE TECHNIQUES REPORTED BY OFFICERS AND CASE OUTCOME. 'SUPPORT' AND 'SETTING LIMITS' WERE THE MOST FREQUENTLY NOTED TECHNIQUES. FOUR VARIABLES -- AGE, SEX, RACE, AND FAMILY LIVING SITUATION -- WERE ASSOCIATED WITH CASE OUTCOME, NOT AS ANTECEDENT VARIABLES, BUT AS INFLUENCES ON THE PROBATION PROCESS. FAMILY LIVING SITUATION APPEARS TO BE THE MOST IMPORTANT INTERVENING VARIABLE. CHILDREN FROM SINGLE-PARENT FAMILIES WERE OVERREPRESENTED IN THE JUVENILE PROBATION POPULATION AND UNDERREPRESENTED IN THE CASES JUDGED SUCCESSFUL. THE SIGNIFICANCE OF THESE AND OTHER FINDINGS FOR PRACTITIONERS, RESEARCHERS, AND THEORETICIANS IS DISCUSSED. SUPPORTING DATA, COPIES OF STUDY INSTRUMENTS, AND A BIBLIOGRAPHY ARE PROVIDED. (LKM)