In no-difference research, no differences are found among groups or conditions. This article summarizes the existing commentary on such research. The characteristics of no-difference research, its acceptance by the research community, strategies for conducting such studies, and its centrality within the experimental and nonexperimental paradigms…

Ten functions of program theory are reviewed: contributing to social science knowledge; assisting policymakers, discriminating between theory failure and program failure, identifying the problem and target group, providing program implementation description, uncovering unintended effects, specifying intervening variables, improving formative use…

Two forms of naturalistic evaluation have appeared within the past decade: (1) a collection of qualitative techniques that are complimentary with conventional quantitative methods; and (2) an alternative paradigm that emphasizes the negotiation of multiple socially constructed realities, interdependence of facts and values, and the emergent…

The need for and applicability of general systems theory in human services evaluation is discussed. The role of evaluation in human services agencies is described and the necessity of combining the programs to be evaluated and the evaluation process itself in a single unifying conceptual model is demonstrated. (Author/AL)

This special issue deals with the preparation of professional evaluators. Evaluation is considered as a profession that warrants specialized training. Aspects of necessary training and descriptions of current programs are discussed. (SLD)

Program theory and implementation process theory contribute, respectively, to specifying the what and the why of program delivery. This article discusses the relationship between these two theories and the types of data collection methods that can be derived from each in order to contribute to more comprehensive evaluation designs. (JAZ)

To enable decision makers to become more aware of the levels of confidence that can be placed in the results of particular computerized decision models, methods for establishing confidence levels are discussed. The U.S. General Accounting Office has developed criteria and review procedures for evaluating computerized policy analysis models.…

A short history of program theory in evaluation is reviewed. Two related problems in program evaluation are discussed and illustrated: (1) how to specify in measurable terms the consensus of theories and values that guides the program; and (2) how to construct a theoretical framework that specifies the use of these measurements. (Author/JAZ)

The goal model is appropriate for evaluating effectiveness in complex service organizations because there are measurable outputs. An empirical method is provided for the identification and measurement of organizational goals. Perception of effectiveness could be improved if goals were made to coincide with the desires of user groups. (DWH)

The consumer of a service is of primary importance when defining groups most concerned with program impact. Program effectiveness for the consumer may be increased through the use of certain guiding principles based on the extension of existing quality assurance and program evaluation methodologies. (Author/RL)

Program theory can be used to improve programs and policies. This article describes a set of techniques for complicating and simplifying program theory, referred to as conceptual and action heuristics. Methods such as analyzing metaphors, clarifying concepts, mapping, component assessment, causal modeling, and decision analysis are discussed. (JAZ)

Time series analysis is applied to an assessment of the temporary and permanent impact of the 1975 Australian Family Law Act and its effect on number of divorces. The application and construct validity of the model is examined. (Author/PN)

The eight articles of this issue examine the nature of differences that arise between qualitative and quantitative researchers in program evaluation in terms of goals and epistemologies. The origins of these differences and their consequences are explored. Authors represent both perspectives but do not defend their ideological turfs. (SLD)

In evaluation, the whole is greater than the sum of the parts when quantitative and qualitative approaches and methods are combined. Some circumstances in which both approaches can be effectively combined are considered, and case studies of two evaluations using multiple methods are presented. (LMO)

Seven chapters present 31 propositions challenging traditional ideas about the nature and practice of program evaluation. Methods to improve evaluation models and approaches and ways to address intermediate and advanced evaluation issues are explored. The discussion also serves as an introduction to the most analytical and comprehensive of the…