THE SAMPLE FOR ALL THREE STUDIES WAS SELECTED FROM NINE METHADONE MAINTENANCE AND SIX DRUG-FREE PROGRAMS IN NEW YORK CITY, WASHINGTON, D.C., CHICAGO, ILL., LOS ANGELES, CALIF., AND SAN FRANCISCO, CALIF. ONE ADDITIONAL PROGRAM HAD BOTH A METHADONE AND A DRUG-FREE UNIT. INTERVIEWS WERE CONDUCTED WITH 82 COUNSELORS, 302 OF THEIR CLIENTS, AND WITH 29 PROGRAM ADMINISTRATORS. THE FIRST STUDY EXAMINED FUNCTIONS AND ACTIVITIES OF COUNSELORS, FINDING THAT WHITE FEMALES WERE MOST PREVALENT AMONG PROFESSIONAL COUNSELORS (PROS), BLACK MALES WERE MOST PREVALENT AMONG EXADDICT COUNSELORS (EAS), AND NONEXADDICT COUNSELORS (NEAS) MORE CLOSELY RESEMBLED EAS THAN PROS. EAS REPORTED SIGNIFICANTLY MORE DRUG USE THAN OTHER GROUPS IN VIRTUALLY EVERY AREA, HALLUCINOGENS BEING THE ONLY EXCEPTION. WITH REGARD TO FUNCTIONS, THE MAIN DIFFERENCE AMONG COUNSELOR GROUPS WAS THE GREATER ACTIVITY OF EAS OVER PROS OUTSIDE THE TREATMENT PROGRAM. THIS DIFFERENCE WAS FOUND IN THREE AREAS OF COUNSELOR FUNCTIONING (COMMUNITY EDUCATION, SOCIALIZING WITH CLIENTS, AND COUNSELING IN THE COMMUNITY). IT WAS DETERMINED THAT ALL COUNSELOR GROUPS SHOULD BE EQUALLY INVOLVED IN PUBLIC SOCIALIZING WITH CLIENTS. THE SECOND STUDY, EXPLORING ATTITUDES OF COUNSELORS AND CLIENTS, OBSERVED FEW DIFFERENCES AMONG COUNSELOR GROUPS. ALL COUNSELORS WERE FAVORABLY DISPOSED TOWARD CLIENTS; BOTH PROFESSIONAL AND PARAPROFESSIONAL COUNSELORS WERE WILLING TO HELP AND TO INTERVENE IN MANY SITUATIONS, AND CLIENTS GENERALLY PERCEIVED THIS. OVERALL, CLIENTS WERE EXTREMELY POSITIVE IN THEIR DESCRIPTIONS OF COUNSELORS. COUNSELORS WERE SEEN AS OPENMINDED AND SUPPORTIVE INDIVIDUALS. FINALLY THE PROGRESS OF CLIENTS IN TREATMENT WAS CONSIDERED, FINDING FEW DIFFERENCES IN CLIENT BACKGROUNDS FOR THE THREE COUNSELOR GROUPS. PRO CLIENTS WERE ABOUT 3 YEARS YOUNGER THAN NEA CLIENTS. IN THE DRUG-FREE MODALITY, PRO CLIENTS REPORTED SLIGHTLY MORE EXCESSIVE ALCOHOL USE THAN NEA CLIENTS AND ALSO HAD APPROXIMATELY ONE MORE TREATMENT EPISODE THAN NEA CLIENTS. ABOUT 15 PERCENT MORE NEA CLIENTS THAN PRO AND NEA CLIENTS HAD BEEN IN JAIL IN THE YEAR PRIOR TO TREATMENT ENTRY. SUPPORTING DATA AND A BIBLIOGRAPHY ACCOMPANY EACH STUDY. (DEP)