The role of human judgment in the development and synthesis of evidence has not been adequately developed or acknowledged within quasi-experimental analysis. Corrective solutions need to confront the fact that causal analysis within complex environments will require a more active assessment that entails reasoning and statistical modeling.…

A practical theory is offered for probing external validity, the generalization of causal relationships. This alternative theory is built around five principles abstracted from research on construct validation. It emphasizes purposive sampling for theoretical ends rather than random sampling to represent a population. (SLD)

Causal models often omit variables that should be included, use variables that are measured fallibly, and ignore time lags. Such practices can lead to severely biased estimates of effects. The discussion explains these biases and shows how to take them into account. (Author)

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)

Explores the role of theory in strengthening causal interpretations in nonexperimental research. Evaluators must conduct theory-driven research, concentrating on "small theory," in that the focus is on the explanation of processes specific to the program being evaluated. Theory-guided treatment research must be programmatic and…

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)

Evaluation is discussed as an information-gathering process. Currently popular evaluation programs are reviewed in relation to decision making and various approaches that seem to contribute to the decision utility of evaluation (e.g. classical approaches, Bayesian approaches, adaptive designs, and model-based evaluations) are described. (Author/AL)

Two chapters of this issue consider critical multiplism as a research strategy with links to meta analysis and generalizability theory. The unifying perspective it can provide for quantitative and qualitative evaluation is discussed. The third chapter explores meta analysis as a way to improve causal inferences in nonexperimental data. (SLD)

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)

Organizational effectiveness is not a clearly defined concept. The author illustrates how the four most widely used models are not uniformly applicable. He states the evaluator must make explicit certain critical choices when measuring effectiveness. These criteria reveal the definition of effectiveness and what is being measured. (DWH)

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…

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)

Seven essays on efforts of evaluate prevention programs aimed at the acquired immune deficiency syndrome (AIDS) are presented. Topics include public health psychology, mathematical models of epidemiology, estimates of incubation periods, ethnographic evaluations of AIDS prevention programs, an AIDS education model, theory-based evaluation, and…