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…

Solutions to methodological problems in medical technologies research synthesis relating to temporal change, persons receiving treatment, research design, analytic procedures, and threats to validity are presented. These solutions should help with the planning and methodogy for research synthesis in other areas. (BS)

Using examples from government program evaluation studies, six areas where research synthesis is more effective than individual studies are presented. Research synthesis can: (1) help match treatment type with recipient type; (2) explain which treatment features matter; (3) explain conflicting results; (4) determine critical outcomes; (5) assess…

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…

Twenty-nine steps necessary for data file preparation for secondary analysis are discussed. Data base characteristics and planned use vary the complexity of the preparation. Required techniques (file verification, sample verification, file merger, data aggregation, file modification, and variable controls) and seven associated pitfalls are defined…

A detailed examination of the Higher Education General Information Survey (HEGIS) data base--its content, development, and past and potential uses for researchers--is presented. Because knowledge of the data elements is crucial for successful secondary analysis, procedures for collecting needed information on the data in HEGIS are suggested. (BS)

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)