Randomized experiments involving education interventions are typically implemented as cluster randomized trials, with schools serving as clusters. To design such a study, it is critical to understand the degree to which learning outcomes vary between versus within clusters (schools), specifically the intraclass correlation coefficient. It is also…

Researchers designing multisite and cluster randomized trials of educational interventions will usually conduct a power analysis in the planning stage of the study. To conduct the power analysis, researchers often use estimates of intracluster correlation coefficients and effect sizes derived from an analysis of survey data. When there is…

It is known that interventions are hard to assign randomly to subjects in social psychological studies, because randomized control is difficult to implement strictly and precisely. Thus, in nonexperimental studies and observational studies, controlling the impact of covariates on the dependent variables and addressing the robustness of the…

In survey sampling the randomized response (RR) technique can be used to obtain truthful answers to sensitive questions. Although the individual answers are masked due to the RR technique, individual (sensitive) response rates can be estimated when observing multivariate response data. The beta-binomial model for binary RR data will be generalized…

A previous multivariate analysis of variance (MANOVA) study of attitudes toward interactive video (ITV) of participants in distance education had indicated that generalized variance was not homogeneous across all groups. Since heterogeneity of variance in MANOVA has previously been shown to change Type I error rates in unequal group size, detected…

A framework for understanding methodological practices from the perspectives of internal validity, external validity, statistical control validity, and construct validity is presented. One hundred doctoral dissertations completed between 1980 and 1988 at a single urban public university were analyzed for various methodological practices and types…