The motivation for this paper is the authors' recent work on several randomized control trials in which they found the primary result, which averaged across subgroups or sites, to be moderated by demographic or site characteristics. They are led to examine a distinction that the Institute of Education Sciences (IES) makes between "confirmatory"…

Scientifically based research used to inform evidence based school reform efforts has been required by the federal government in order to receive grant funding since the reenactment of No Child Left Behind (2002). Educational evaluators are thus faced with the challenge to use rigorous research designs to establish causal relationships. However,…

The potential for music programs to promote psychosocial wellbeing in mainstream schools is recognised in both policy and research literature. Despite this recognition, there is a dearth of consistent research evidence supporting this link. Authors attribute this lack of consistent evidence to limitations in the areas of research design and…

This paper introduces a variation on the post-test only cohort control design and addresses questions concerning both the methodological credibility and the practical utility of employing this design variation in evaluations of large-scale complex professional development programmes in mathematics education. The original design and design…