PROGRAM EVALUATION, IN ALCOHOL, DRUG ABUSE, AND MENTAL HEALTH FIELDS, IS IN A PERIOD OF TRANSITION. THE RIGHTS AND RESPONSIBILITIES OF EVALUATORS, AS REFLECTED IN THIS TRANSITION, REST ON A BROAD CONCEPTUALIZATION OF PROGRAM EVALUATION. PROGRAM EVALUATION IS A COMPOSITE OF PROCESSES THAT RELATE TO SHORT RANGE AND LONG RANGE OBJECTIVE ASSESSMENT OF THE WORTH OF A HUMAN SERVICE ORGANIZATION OR SYSTEM AND PROCESSES THAT RELATE TO THE PLANNING FOR AND THE IMPLEMENTATION OF CHANGES. IT INCLUDES THE EVALUATION OF STRUCTURE AND PROCESS, IN ADDITION TO OUTCOME, AND ENCOMPASSES OTHER DEFINITIONS USED IN THE FIELD OF SCIENTIFIC MANAGEMENT: COST-BENEFIT ANALYSIS, SYSTEMS ANALYSIS, UTILIZATION REVIEW AND QUALITY AUDIT, PLANNING-PROGRAMMING-BUDGETING SYSTEMS, AND OPERATIONS RESEARCH. THE EVALUATIVE PROCESS CONSISTS OF FOUR PHASES: (1) FORMULATION OF PROGRAM GOALS; (2) SELECTION OF CRITERIA TO BE USED IN DETERMINING SUCCESS; (3) DESIGN AND CONDUCT OF STUDIES NECESSARY FOR PROGRAM EVALUATION; AND (4) INTERPRETATION OR EXPLANATION OF EVALUATION FINDINGS TO APPROPRIATE GROUPS. IN THE FIRST TWO PHASES, EVALUATORS MUST HAVE CONTACT WITH ALL RELEVANT GROUPS, MUST PLAY A ROLE IN CONCEPTUALIZING THE SYSTEM TO BE EVALUATED, AND MUST HAVE THE RIGHT TO A SIGNIFICANT VOICE IN SPECIFYING WHAT GOALS ARE TO BE EVALUATED AND HOW THESE GOALS ARE TO BE STATED. IN THE THIRD PHASE, EVALUATORS HAVE THE RESPONSIBILITY OF SELECTING AND UTILIZING MOST EFFECTIVELY METHODS THAT WILL ASSURE UNBIASED ASSESSMENT. IN THE FOURTH AND FINAL PHASE, EVALUATORS ARE RESPONSIBLE FOR PROVIDING A COMPREHENSIBLE INTERPRETATION OF DATA TO ALL RELEVANT GROUPS (PROGRAM PERSONNEL, FUNDING SOURCES, CLIENTS, AND THE PUBLIC). NOTES ARE INCLUDED. (DEP)