Maximizing Power in Generalizability Studies Under Budget Constraints

Generalizability theory provides a framework for examining the dependability of behavioral measurements. When designing generalizability studies, two important statistical issues are generally considered: power and measurement error. Control over power and error of measurement can be obtained by manipulation of sample size and/or test reliability. In generalizability theory, the mean error variance is an estimate that takes into account both these statistical issues. When limited resources are available, determining an optimal measurement design is not a simple task. This article presents a methodology for minimizing mean error variance in generalizability studies when resource constraints are imposed.