An appropriate estimate of statistical power is critical for the design of intervention studies. Although the inclusion of a pretest covariate in the test of the primary outcome can increase statistical power, samples selected on the basis of pretest performance may demonstrate range restriction on the selection measure and other correlated…

Little is known empirically about intraclass correlations (ICCs) for multisite cluster randomized trial (MSCRT) designs, particularly in science education. In this study, ICCs suitable for science achievement studies using a three-level (students in schools in districts) MSCRT design that block on district are estimated and examined. Estimates of…

In the 21st century, students have access to a plethora of information. As such, the skills required to access and effectively sort through this information (information literacy skills) become ever more important for success in both academic and non-academic settings. This study sought to assess the efficacy of two educational games designed to…

This paper presents evidence on the amount of classroom variation in gains across various domains of achievement within the Tennessee Voluntary Pre-Kindergarten (TN-VPK) program; the data are taken from the randomized control trial (RCT) design of the TN-VPK evaluation. This study explores areas where those differences are largest, and offers…

The purpose of this replication study was to examine the impact of the Teacher Study Group (TSG) professional development in vocabulary on first-grade teachers' knowledge of vocabulary instruction and observed teaching practice, and on students' vocabulary knowledge. Sixty-two schools from 16 districts in four states were randomly assigned to…

The present study examined the effectiveness of the oral history approach with respect to students' historical competence. A total of 35 ninth-grade classes (N = 900) in Germany were randomly assigned to one of four conditions--live, video, text, or a (nontreated) control group--in a pretest, posttest, and follow-up design. Comparing the three…

Research Findings: This article examines whether time spent in free choice and teacher-directed activity settings within preschool was associated with indicators of school readiness and the extent to which children's learning was associated with the quality of teachers' behavior within these settings. Participants were 325 preschool teachers and…

As part of the 2010 economic stimulus, a $55 million "Investing in Innovation" (i3) grant from the US Department of Education was awarded to scale up Reading Recovery across the nation. This paper presents the final round of results from the large-scale, mixed methods randomized evaluation of the implementation and impacts of Reading…

The present study used a randomized control trial to examine the effects of a widely used multicomponent Tier 2-type intervention, Passport to Literacy, on the reading ability of 221 fourth graders who initially scored at or below the 30th percentile in reading comprehension. Intervention was provided by research staff to groups of 4-7 students…

To better understand the nature of impairment resulting from attention-deficit/hyperactivity disorder (ADHD) for students in a post-secondary education (PSE) setting, the authors analyzed the symptoms and associated impairment of 135 students with a diagnosis of ADHD who were recruited via Student Disability Services in Canadian post-secondary…

The present study used a randomized control trial to examine the effects of a widely-used multi-component Tier 2 type intervention, Passport to Literacy, on the reading ability of 221 fourth graders who initially scored at or below the 30th percentile in reading comprehension. Intervention was provided by research staff to groups of 4-7 students…

Objective: Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) A-criteria for ADHD were expanded to include new descriptors referencing adolescent and adult symptom manifestations. This study examines the effect of these changes on symptom endorsement in a sample of adolescents with ADHD (N = 259; age range = 10.72-16.70).…

The capacity of the field to conduct power analyses for group randomized trials (GRTs) of educational interventions has improved over the past decade (Authors, 2009). However, a power analysis depends on estimates of design parameters. Hence it is critical to build the empirical base of design parameters for GRTs across a variety of outcomes and…