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…

Comparison studies conducted to determine which instructional interventions are most efficient for teaching discrete behaviors to individuals with disabilities are potentially valuable, although some threats to internal validity may be more likely in these studies. Studies included in this review typically met common internal validity standards,…

Randomized clinical trials underpin evidence-based clinical practice, but flaws in their conduct may lead to biased estimates of intervention effects and hence invalid treatment recommendations. The main approach to the empirical study of bias is to collate a number of meta-analyses and, within each, compare the results of trials with and without…

Anxiety in autism is commonly reported by parents, but teacher reports of anxiety in their students with autism have received little attention. This paper presents the results from the first systematic review on anxiety in children with autism at school. Six intervention studies (five of which were based upon cognitive-behavioural therapy) and 26…

Debate is occurring about which result interpretation aides focused on examining the experimental effect should be used in single-subject experimental research. In this study, we examined seven nonoverlap methods and compared results using each method to judgments of two visual analysts. The data sources for the present study were 36 studies…

Randomized controlled trials (RCTs) and regression discontinuity (RD) studies both provide estimates of causal effects. A major difference between the two is that RD only estimates local average treatment effects (LATE) near the cutoff point of the forcing variable. This has been cited as a drawback to RD designs (Cook & Wong, 2008).…

Precise educational interventions are the sine qua non of services for students with exceptionalities. Applying interventions riddled with inconsistencies, therefore, interferes with the growth and learning potential of students who need these interventions. This research synthesis documents the inconsistencies revealed during a critical analysis…

This "What Works Clearinghouse Procedures and Standards Handbook (Version 3.0)" provides a detailed description of the standards and procedures of the What Works Clearinghouse (WWC). The remaining chapters of this Handbook are organized to take the reader through the basic steps that the WWC uses to develop a review protocol, identify…

Formative and design experiments represent a methodology uniquely suited for educational research. Providing a practical overview of this emerging approach, the authors address the following questions: What is the origin of formative and design experiments and how do they compare to other approaches to investigating interventions in classrooms?…