Randomised trials are often funded by commercial companies and methodological studies support a widely held suspicion that commercial funding may influence trial results and conclusions. However, these studies often have a risk of confounding and reporting bias. The risk of confounding is markedly reduced in meta-epidemiological studies that…

It is now widely accepted that the standard inferential toolkit used by the scientific research community--null-hypothesis significance testing (NHST)--is not fit for purpose. Yet despite the threat posed to the scientific enterprise, there is no agreement concerning alternative approaches for evidence assessment. This lack of consensus reflects…

Network meta-analysis is a popular method to synthesize the information obtained in a systematic review of studies (e.g., randomized clinical trials) involving subsets of multiple treatments of interest. The dominant method of analysis employs within-study information on treatment contrasts and integrates this over a network of studies. One…

Motivational interviewing (MI) is applied in a variety of clinical and coaching models to promote behavior change, with increasing interest in its potential to optimize school-based implementation fidelity. Yet there has been less consideration of fidelity indicators for MI-embedded coaching and links to outcomes. We leveraged secondary data from…

This study presents findings from a 58 high-school group-randomized controlled trial testing the effectiveness of training in a multitiered system of supports for behavior (MTSS-B) framework, which was leveraged to reduce students' risk for emotional and behavior disorders. The trial tested the impact of MTSS-B, which included (a) training in the…

Evaluating blocked randomized experiments from a potential outcomes perspective has two primary branches of work. The first focuses on larger blocks, with multiple treatment and control units in each block. The second focuses on matched pairs, with a single treatment and control unit in each block. These literatures not only provide different…

Poor program implementation constitutes one explanation for null results in trials of educational interventions. For this reason, researchers often collect data about implementation fidelity when conducting such trials. In this article, we document whether and how researchers report and measure program fidelity in recent cluster-randomized trials.…

The contrary of stochastic independence splits up into two cases: pairs of events being favourable or being unfavourable. Examples show that both notions have quite unexpected properties, some of them being opposite to intuition. For example, transitivity does not hold. Stochastic dependence is also useful to explain cases of Simpson's paradox.

Background: This paper presents the baseline characteristics and their moderators in the Healthy Learning Mind (HLM)-- school-based cluster-randomized controlled trial. Objectives: The paper evaluates the state of various measures of well-being, their moderators and how these results compare to national and global norms/population studies.…

We estimate the societal costs associated with corequisite and traditional pre-requisite English developmental education and compare them to societal benefits. Our context is the randomized controlled trial conducted by Miller et al. (2022) that estimated the effects of three different approaches to English corequisites implemented in 5 Texas…

This paper discusses, compares, and contrasts 4 different models for bringing evidence from randomised controlled trials (RCTs) into practice and into practical reasoning. I look at what questions the models can and cannot answer, what role they accord to RCT evidence, and what their possible attraction for practitioners might be. The models are…

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…

A substantial number of randomized trials of educational interventions that have been conducted over the past two decades have produced null results, with either no impact or an unreliable estimate of impact on student achievement or other outcomes of interest. The investment of time and money spent implementing such trials warrants more useful…

For binary experimental data, we discuss randomization-based inferential procedures that do not need to invoke any modeling assumptions. We also introduce methods for likelihood and Bayesian inference based solely on the physical randomization without any hypothetical super population assumptions about the potential outcomes. These estimators have…

Education decisionmakers need access to the best evidence about the effectiveness of education interventions, including practices, products, programs, and policies. It can be difficult, time consuming, and costly to access and draw conclusions from relevant studies about the effectiveness of interventions. The What Works Clearinghouse (WWC)…