Though previously unacknowledged, a SMART (Sequential Multiple Assignment Randomized Trial) design uses both regression discontinuity (RD) and randomized controlled trial (RCT) designs. This combination structure creates a conceptual symbiosis between the two designs that enables both RCT- and previously unrecognized, RD-based inferential claims.…

External validity is an important parameter that needs to be considered for decision making in health research, but no widely accepted measurement tool for the assessment of external validity of randomized controlled trials (RCTs) exists. One of the most limiting factors for creating such a tool is probably the substantial heterogeneity and lack…

Single-case experimental designs (SCEDs) have a long history in clinical and educational disciplines. One underdeveloped area in advancing SCED design and analysis is understanding the process of how internal validity threats and operational concerns are avoided or mitigated. Two strategies to ameliorate such issues in SCED involve replication and…

The Campbellian validity typology has been used as a foundation for outcome evaluation and for developing evidence-based interventions for decades. As such, randomized control trials were preferred for outcome evaluation. However, some evaluators disagree with the validity typology's argument that randomized controlled trials as the best design…

The purpose of this article is to examine the application of randomized controlled trial (RCT) methodology for determining the efficacy of school-based interventions in general and special education. In education science, RCTs are widely acknowledged as the gold standard of efficacy research, with other methodologies relegated to a lower level of…

This paper seeks to raise awareness among educational researchers and practitioners of some significant weaknesses and internal contradictions of randomised control trials (RCTs). Although critiques throughout the years from education scholars have pointed to the detrimental effects of this experimental approach on education practice and values,…

Purpose: In a companion paper, we found no statistical reason to favor percentage syllables stuttered (%SS) over parent-reported stuttering severity as a primary outcome measure for clinical trials of early stuttering. Hence, considering the logistical advantages of the latter measure, we recommended parent-reported stuttering severity for use as…

Randomized controlled trials are a special case of designs using an unbiased instrument to take care of confounders even if they are unmeasured or unknown. Another example of studies using instrumental variables is the Mendelian experiment and Directed Acyclic Graphs show the power of such designs to enhance the internal validity. It is argued…

This chapter highlights the key assumptions underlying Randomized Control Trials (RCTs) and illustrates them with regard to the practice of RCTs in the realm of child and adolescent development. Given the prominence of RCTs in policy research, we analyze the possible ways in which these assumptions might not be met by single randomized…

We initiated and structured a single program that supervised teachers, some with neuroscience or psychology degrees, to collaborate and explore the effects of science of learning-translated pedagogy. This article reports on the 34 findings from teacher-led randomized controlled trials (RCTs) and replications. Teachers designed trials, looking at…

Randomized controlled trials in lower-income countries have demonstrated ways to increase learning, in specific settings. This study uses a large-scale, nationwide RCT in Ghana to show the external validity of four school-based interventions inspired by other RCTs. Even though the government implemented the programs within existing systems,…

This paper reviews the use of multiple trials, defined as multiple sites or multiple arms in a single evaluation and replications, in evaluating social programs. After defining key terms, the paper discusses the rationales for conducting multiple trials, which include increasing sample size to increase statistical power; identifying the most…

EBP -- evidence-based policy and practice -- has generated intense controversy. A rough continuum of positions can be discerned: At one pole are "tough-minded" commentators distinguished by their support of EBP; however, there are serious internal differences in this camp, for some regard randomised field trials (RFTs) as the gold…

Randomization of large number of participants to different treatment groups is often not a feasible or preferable way to answer questions of immediate interest to professional practice. Single case designs (SCDs) are a class of research designs that are experimental in nature but require only a few participants, all of whom receive the…

Although several studies have examined the effectiveness of reading fluency interventions, the methodological rigor of these studies remains unclear. The purpose of this study was to examine the quality of randomized controlled trial (RCT) reading fluency intervention studies using the Council for Exceptional Children (CEC) standards. Twenty-six…