OBJECTIONS TO CORRECTIONAL TREATMENT HAVE BEEN MADE ON TWO GROUNDS: SUCH TREATMENT IS UNETHICAL BECAUSE IT IS INEVITABLY COERCIVE; AND THERE IS NO EVIDENCE THAT TREATMENT IS EFFECTIVE IN REDUCING CRIME. THE TWO OBJECTIVES ARE INTERTWINED. THE EXTENT TO WHICH OFFENDERS CAN REASONABLY BE REQUIRED TO TAKE PART IN TREATMENT PROGRAMS IS DEPENDENT ON THE PROBABILITY THAT THE TREATMENT WILL BE SUCCESSFUL. DATA FROM A 13-YEAR STUDY OF COMMUNITY VERSUS INSTITUTIONAL TREATMENT IN THE CALIFORNIA YOUTH AUTHORITY ARE THE BASIS OF AN ANALYSIS OF THREE TYPES OF OFFENDERS: CONFLICTED YOUTHS; PASSIVE-CONFORMIST YOUTHS; AND POWER-ORIENTED YOUTHS. THE BEHAVIORAL CHARACTERISTICS OF EACH TYPE ARE DESCRIBED, TOGETHER WITH COMMONLY PRESCRIBED TREATMENT STRATEGIES, TREATMENT SUCCESS RATES, AND OTHER TREATMENT OUTCOME MEASURES. CONSIDERABLE DIFFERENCES IN TREATMENT SUCCESS ARE FOUND AMONG THE THREE GROUPS. THE ANALYSIS SUGGESTS THAT THE IMPACT OF TREATMENT IS NOT SO MUCH NEGATIVE AS COMPLEX. A CASE IS MADE FOR THE IMPORTANCE OF RECOGNIZING DIFFERENCES AMONG OFFENDERS AND SELECTING TREATMENT PROGRAMS ACCORDINGLY. TREATMENT SUCCESS DATA FOR THE POWER-ORIENTED YOUTHS, THE GROUP CONTAINING THE MOST SERIOUS OFFENDERS, SUGGEST A DILEMMA. THERE IS NO TREATMENT SUCCESS BASIS FOR REQUIRING TREATMENT FOR THIS GROUP. YET THE POWER-ORIENTED OFFENDER MUST CONTINUE TO BE TREATED IN EXPERIMENTAL PROGRAMS AND IS UNLIKELY TO VOLUNTEER FOR SUCH PROGRAMS. FURTHER RESEARCH IS ALSO NEEDED ON TREATMENT OF THE PASSIVE-CONFORMIST GROUP BEFORE COERCED TREATMENT CAN BE CONSIDERED. EXPLANATIONS FOR THE SHORT-TERM SUCCESS AND LONG-TERM FAILURE OF TREATMENT IN THIS GROUP ARE NEEDED. A LIST OF REFERENCES IS INCLUDED.