Background/Context: Over the past twenty plus years, the What Works Clearinghouse (WWC) has reviewed over 1,700 studies, cataloging effect sizes for 189 interventions. Some 56% of these interventions include results from multiple, independent studies; on average, these include results of [approximately]3 studies, though some include as many as 32…

Reviews some of the more salient conceptual features of generalizability (G) theory. Provides a framework for considering some misconceptions about G theory. Focuses on particularly prevalent or serious misconceptions. G theory provides a rich conceptual framework and tools for working with a defined universe, but it does not tell an investigator…

This paper presents a review of the literature on reliability in qualitative studies. Reliability is defined as the extent to which studies can be replicated, using the same methods, and getting the same results. It is the degree to which data are independent of the accidental circumstances of the research. The review includes the following three…