IT IS ARGUED THAT ALL EVALUATION RESEARCH NECESSARILY RESTS ON SIGNIFICANT MORAL AND POLITICAL VALUE JUDGMENTS WHICH, TOGETHER WITH METHODOLOGICAL FACTORS, AFFECT THE SOCIAL PROBLEM DEFINITION PROCESSES THAT SURROUND SOCIAL PROGRAMS. EVALUATION RESEARCH IMPLICITLY ENDORSES PARTICULAR IDEOLOGICAL PERSPECTIVES AND THEREFORE HAS BROADER IMPLICATIONS FOR SOCIAL CHANGE. HOWEVER, IF DESIGNS CAPITALIZE ON THE INEVITABLE VALUE JUDGMENTS RATHER THAN IGNORE THEM, EVALUATION RESEARCH CAN PLAY A PROGRESSIVE ROLE. A DECISION THEORY PERSPECTIVE IS USEFUL IN MAKING THESE VALUE JUDGMENTS EXPLICIT AND IN APPLYING THEM IN THE CHOICE OF RESEARCH DESIGN ALTERNATIVES. AN EXAMPLE OF SUCH AN APPLICATION OF DECISION THEORY IN THE DESIGN OF AN EVALUATION STUDY FOR A PRISON BEHAVIORAL MODIFICATION PROGRAM IS PRESENTED. A LIST OF REFERENCES IS INCLUDED. (AUTHOR ABSTRACT MODIFIED--LKM)