A common motivation for adding control variables to statistical models is to reduce the potential for spurious findings when analyzing non-experimental data and to thereby allow for more reliable causal inferences. However, as I show here, unless "all" potential confounding factors are included in an analysis (which is unlikely to be…

Discipline-based education researchers have a natural laboratory--classrooms, programs, colleges, and universities. Studies that administer treatments to multiple sections, in multiple years, or at multiple institutions are particularly compelling for two reasons: first, the sample sizes increase, and second, the implementation of the treatments…

Attrition occurs when members of the initial research sample are not part of the final analysis sample, such as due to missing data or leaving the study. Both the overall sample attrition and the differences in attrition between the groups can affect the statistical equivalence of the sample and create potential for bias. The WWC has given careful…

Attrition occurs when members of the initial research sample are not part of the final analysis sample, such as due to missing data or leaving the study. Both the overall sample attrition and the differences in attrition between the groups can affect the statistical equivalence of the sample and create potential for bias. The WWC has given careful…

This Methodological Brief introduces the reader to the regression discontinuity design (RDD), which is a method that when used correctly can yield estimates of research treatment effects that are equivalent to those obtained through randomized control trials and can therefore be used to infer causality. However, RDD does not require the random…

Reviewing the studies on differential susceptibility presented in this section, we argue that the time is ripe to go beyond correlational designs to differential susceptibility experiments. In such experiments, randomization prevents hidden moderator effects on the environment and guarantees the independence of moderator and outcome, while the…

Conventional cognitive-behavioral therapy for social anxiety disorder, which is closely based on the treatment for depression, has been shown to be effective in numerous randomized placebo-controlled trials. Although this intervention is more effective than waitlist control group and placebo conditions, a considerable number of clients do not…

A review of the literature on Rett syndrome (RS) for school-based professionals is presented from a behavioral perspective. A description of RS is provided, including distinctive physical, behavioral, and emotional features, diagnostic criteria for classic and "formes frustes" forms of RS, and stages of the disorder. The similarities and…

This descriptive and case-control study was carried out in a pediatric oncology outpatient clinic to determine the school-related physical, social, and psychological problems and problems experienced in academic achievement of children treated for cancer. The sample of the study consisted of 56 Turkish patients with cancer, aged 7-18 years, who…

Measures of head injury, executive functioning, and intelligence were given to a community sample composed of 102 male perpetrators of intimate partner aggression (IPA) and 62 nonaggressive men. A history of head injury and lower mean score on a measure of verbal intelligence were associated with the frequency of male-perpetrated physical IPA as…

For RCTs of education interventions, it is often of interest to estimate associations between student and mediating teacher practice outcomes, to examine the extent to which the study's conceptual model is supported by the data, and to identify specific mediators that are most associated with student learning. This article develops statistical…

In 1989, Hallam Hurt, a neonatologist in Philadelphia, started recruiting poor inner-city women for a study of how cocaine use during pregnancy affects the developing fetus. Dr. Hurt enrolled women who had used cocaine while pregnant and balanced them against a control group of equally poor women who had not taken any drugs. Years later, when the…

Longer life expectancy should encourage human capital accumulation, since a longer time horizon increases the value of investments that pay out over time. Previous work has been unable to determine the empirical importance of this life-expectancy effect due to the difficulty of isolating it from other effects of health on education. We examine a…

Interest has rapidly increased in studies that randomly assign classrooms or schools to interventions. When well implemented, such studies eliminate selection bias, providing strong evidence about the impact of the interventions. However, unless expected impacts are large, the number of units to be randomized needs to be quite large to achieve…

Studies the language proficiency of the Turkish returnees from Germany who were either born in Germany or emigrated there with their parents at a young age. Results indicate that returnees have a deficit in cognitive academic language proficiency compared to control groups and that a correlation exists between language proficiency in Turkish,…