Questions regarding the generalizability of results from educational experiments have been at the forefront of methods development over the past five years. This work has focused on methods for estimating the effect of an intervention in a well-defined inference population (e.g., Tipton, 2013; O'Muircheartaigh and Hedges, 2014); methods for…

I define a treatment effect in terms of a comparison of outcomes and provide a typology of all possible comparisons that can be used to estimate treatment effects, including comparisons that are relatively unknown in both the literature and practice. I then assess the relative merit, worth, and value of all possible comparisons based on the…

A structural equation modeling approach to scale reliability evaluation can be employed to estimate generalizability theory indexes in settings where sampling of subjects and conditions is carried out. In one- and two-facet crossed designs, it is demonstrated how this method can be used to obtain estimates of relative generalizability…

In education research, a polar distinction is frequently made to describe and produce different kinds of research: "quantitative" versus "qualitative." In this article, the authors argue against that polarization and the associated polarization of the "subjective" and the "objective," and they question the attribution of generalizability to only…

An evaluation system which would describe and assess statewide services for preschool children is described. Component theory conceptualizes the unit of analysis for evaluation as the component. This approach increases the generalizability and utilization of evaluations and enhances the ability to evaluate several programs at the state level.…