The current review addresses the validity of published meta-analyses in education that determines the credibility and generalizability of study findings using a total of 56 meta-analyses published in education in the 2000s. Our objectives were to evaluate the current meta-analytic practices in education, identify methodological strengths and…

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…

Generalizability theory is described as a way to provide a unified framework for examining the dependability of measurements in the health sciences. Generalizability theory is appropriate whether the measurement is norm- or criterion-referenced, an individual or aggregate-level variable, and it is useful when there are single or multiple sources…

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…

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)

An empirical investigation of methodological issues associated with evaluating treatment effect in single-subject research (SSR) designs is presented. This investigation: (1) conducted a generalizability (G) study to identify the sources of systematic and random measurement error (SRME); (2) used an analytic approach based on G theory to integrate…