Six potential problems with the use of randomized experiments to evaluate programs in the field are addressed. Problems include treatment dilution, treatment contamination or confounding, inaccurate case flow and power estimates, violations of the random assignment processes, changes in the environmental context, and changes in the treatment…

Why conclusions of many outcome evaluations do not stand up to scrutiny is discussed, drawing on examples from evaluations of drug abuse prevention programs. Factors that undermine these studies are largely the result of social-structural problems that influence the design and implementation of the research. (SLD)

This article refers to two uses of the term "program theory": (1) microtheory to describe the model of the program; and (2) macrotheory which is concerned with factors that affect social change both within and outside programs. Barriers to successful utilization of evaluation and suggestions to overcome those barriers are discussed. (JAZ)

Six articles provide an overview of the multiple approaches to evaluating the problems of homelessness and introduce the challenges of evaluating interventions for the homeless. The first part focuses on research about homelessness, and the second part describes major demonstration programs and their evaluations. (SLD)

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)

This issue includes four papers conceptualizing and analyzing the issues of evaluation and social justice. An evaluative model is presented as a way of improving educational practice at the school level. Implications of evaluation are examined relative to a moral and ethical stance rooted in conceptions of social justice. (SLD)