Background/Context: A well-designed intervention often involves multiple phases. A justifying theoretical argument is that, to prevent fade-outs, the benefit of a treatment in an earlier phase will need to be reinforced by follow-up treatments in the later phases (Cunha & Heckman, 2007). Thus, in evaluations of such programs, a research…

This paper examines the scalability of the results from the Tennessee Student-Teacher Achievement Ratio (STAR) Project, a prominent educational experiment. We explore how the misalignment between the experimental design and the econometric model affects researchers' ability to learn about the intervention's scalability. We document heterogeneity…

The present simulation study examined the statistical properties (namely, Type I error and statistical power) of various novel randomized single-case multiple-baseline designs and associated randomized-test analyses for comparing the A- to B-phase immediate abrupt outcome changes in two independent intervention conditions. It was found that with…

The growth of school choice programs, including publicly funded private school vouchers and charter schools, raises questions about the relative effectiveness and cost of these options. A recent Wisconsin Institute for Law & Liberty (WILL) report analyzes publicly available test score data in Wisconsin to investigate these questions. The…

Multiple imputation (MI) is a popular method for handling missing data. In education research, it can be challenging to use MI because the data often have a clustered structure that need to be accommodated during MI. Although much research has considered applications of MI in hierarchical data, little is known about its use in cross-classified…

This tutorial uses publicly available data from drug makers and the Food and Drug Administration to guide learners to estimate the confidence intervals of COVID-19 vaccine efficacy rates with a Bayesian framework. Under the classical approach, there is no probability associated with a parameter, and the meaning of confidence intervals can be…

A randomized experiment that measures the impact of a social policy in a sample of the population reveals whether the policy will work on average with universal application. An experiment that includes only the subset of the population that volunteers for the intervention generates narrower "proof-of-concept" evidence of whether the…

Research related to the developmental disability (DD) community should include collaboration "with" individuals with DD. Unfortunately, people with DD are infrequently involved in research projects in meaningful ways, and there is little guidance about how to collaborate equitably with researchers with DD. The purpose of this article is…

In narrative synthesis of evidence, it can be the case that the only quantitative measures available concerning the efficacy of an intervention is the direction of the effect, that is, whether it is positive or negative. In such situations, the sign test has been proposed in the literature and in recent Cochrane guidelines as a way to test whether…

In paired experiments, participants are grouped into pairs with similar characteristics, and one observation from each pair is randomly assigned to treatment. The resulting treatment and control groups should be well-balanced; however, there may still be small chance imbalances. Building on work for completely randomized experiments, we propose a…

In organizations that are seeking a high degree of maturity, it is necessary to achieve a statistical control of software processes and to know their behavior and operational performance. The approach adopted for the research involves reading articles and experience performance reports, practical cases, discussion, the use of games and simulators,…

The Upward Bound Math and Science (UBMS) program at Temple University (TU) seeks to guide first-generation, low-income high school students from Philadelphia in their quest to obtain postsecondary STEM degrees that lead to related careers. This study aims to evaluate the efficacy of the program by analyzing its students' performance in light of…

Background: An efficacy study based on a randomized controlled trial (RCT) was designed to evaluate the impact of ASSISTments on math learning among middle school students, including those from high-needs rural schools. Despite extensive recruitment efforts in 2021 (during the pandemic), only a few schools and their teachers agreed to participate,…

This is a technical report detailing the analytic methods used to assess the effects of a virtual professional learning community (vPLC)-enhanced ASSISTments intervention. The report uses a quasi-experimental design and partially nested regression model to account for clustering and reveals that while overall effects were positive but not…

The major aim of this manuscript is to bring together two important topics that have recently received much attention in child and adolescent research, albeit separately from each other: single-case experimental designs and statistical mediation analysis. Single-case experimental designs (SCEDs) are increasingly recognized as a valuable…