An optimistic view of the potential of evaluation to be a force for social improvement is presented. The most important unfinished task for evaluation may be to expand the logic of value judgments. In addition, the social usefulness of evaluation will depend on its credibility and the professionalism of evaluators. (SLD)

Evaluation is an act of persuasion directed to a specific audience concerning the solution of a problem. The process of evaluation is prescribed by the nature of knowledge--which is generally complex, always uncertain (in varying degrees), and not always propositional--and by the nature of logic, which is always selective. In the process of…