IT IS QUITE CLEAR THAT DURING THE THREE-AND-ONE-HALF YEARS OF THE COMMUNITY CENTERED DRUG PROGRAM SURVEYED IN THIS REPOT, THE NATURE OF THE BASIC POPULATION OF IDENTIFIED DRUG ABUSERS CHANGED DRAMATICALLY. THAT CHANGE WAS MOST APPARENT IN TERMS OF FOUR VARIABLES: TYPE OF COMMITMENT OFFENSE, AGE AT IDENTIFICATION, MAJOR DRUG OF ABUSE, AND ETHNIC BACKGROUND. AS THE POPULATION BECAME COMPOSED OF FEWER NARCOTIC AND DRUG OFFENDERS AND MORE CRIMES-AGAINST-PERSONS OFFENDERS, AS ITS AGE LEVELS DECLINED, AS THE PROPORTION OF MORE HEAVILY INVOLVED ABUSER OF ADDICTIVE DRUGS DECREASED, AND AS THE PROPORTIONS OF WHITE WARDS LESSENED, THE DATA SUGGEST THAT THE COMMUNITY PROGRAM SERVICES HAD LESS IMPACT MAINTAINING DRUG ABUSING WARDS ON PAROLE. THIS SUGGESTION MUST BE QUALIFIED, HOWEVER, BY THE PROBABILITY THAT OTHER FACTORS THAN POPULATION CHANGES IMPINGED ON PAROLE OUTCOME. UNTIL THE DEGREE OF RELATIVE IMPACT OF THESE OTHER FACTORS CAN BE ASSESSED, THE IMPACT OF POPULATION CHANGE CANNOT BE DETERMINED.(AUTHOR ABSTRACT) ....BDS