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"…

This quasi-experimental study investigated how explicit instruction about multiple modes of representation (MMR) impacted grades 7 (n = 61) and 8 (n = 141) students' learning and multimodal use on end-of-unit assessments. Half of each teacher's (n = 3) students received an intervention consisting of explicit instruction on MMR in science…

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…

Using data from a nationwide, large-scale experimental study of the effects of a connected classroom technology on student learning in algebra (Owens et al., 2004), this dissertation focuses on challenges that can arise in estimating treatment effects in educational field experiments when samples are highly heterogeneous in terms of various…

There is evidence to suggest that the effects of behavioral interventions may be limited to specific types of individuals, but methods for evaluating such outcomes have not been fully developed. This study proposes the use of finite mixture models to evaluate whether interventions, and, specifically, group randomized trials, impact participants…