Randomized experiments involving education interventions are typically implemented as cluster randomized trials, with schools serving as clusters. To design such a study, it is critical to understand the degree to which learning outcomes vary between versus within clusters (schools), specifically the intraclass correlation coefficient. It is also…

Frequentists' inference often delivers point estimators associated with confidence intervals or sets for parameters of interest. Constructing the confidence intervals or sets requires understanding the sampling distributions of the point estimators, which, in many but not all cases, are related to asymptotic Normal distributions ensured by central…

Purpose: Key considerations in designing multilevel experimental studies are to efficiently use resources and to determine the sample size allocation such that designs have adequate statistical power. The utility of optimal sampling and power analysis results depends on accurate information about design parameters, such as intraclass correlations…

Current practice for conducting power analyses in hierarchical trials using survey based ICC and effect size estimates may be misestimating power because ICCs are not being adjusted to account for treatment effect heterogeneity. Results presented in Table 1 show that the necessary adjustments can be quite large or quite small. Furthermore, power…

Background: There is an increased focus on randomized trials for proximal behavioral outcomes in early childhood research. However, planning sample sizes for such designs requires extant information on the size of effect, variance decomposition, and effectiveness of covariates. Objectives: The purpose of this article is to employ a recent large…

Although scalable programs, such as online courses, have the potential to reach broad audiences, they may pose challenges to evaluating learners' knowledge and skills. Automated scoring offers a possible solution. In the current paper, we describe the process of creating and testing an automated means of scoring a validated measure of teachers'…

The technology policies included on instructors' syllabi vary greatly and, in some cases, may unfavorably influence students' perceptions of the instructor. To examine this hypothesis, we randomly assigned college students enrolled in psychology courses at two different institutions (N = 163) to groups in which they viewed different syllabi for a…

It has been claimed that physical activity has a positive effect on not only health but also on school performance. Using data from a randomised school-intervention study, this paper investigates whether different interventions promoting physical activity affect school performance in primary school children. The results indicate that on average,…

The purpose of this study was to evaluate the psychometric properties of a Perceived Benefits Scale, a Perceived Barriers Scale, and a Physical Activity Enjoyment Scale with data from a group randomized controlled trial (RCT) and a test-retest study with 1-week interval. In the group RCT at baseline and Week 17, 1,012 fifth- to eighth-grade girls…

Of all the approaches to collecting data in the social sciences, the administration of questionnaires to respondents is among the most prevalent. Despite their popularity, there is broad consensus among survey design experts that using these items introduces excessive error into respondents' ratings. The authors attempt to answer the following…

The homeless represent an extremely disadvantaged population that fare worse than minority groups in access to preventive services and health, and minority groups fare worse than Whites. Early detection screening for colorectal cancer (CRC) saves lives, but empirical data about CRC screening practices among homeless Blacks and Whites are limited.…

Objective. In a randomized controlled trial we compared two models of community health worker-led diabetes medication decision support for low-income Latino and African American adults with diabetes. Most outcomes were improved when community health workers used either an interactive e-Health tool or print materials. This article investigates…

Research Findings: To extend findings that are mainly based on North American studies with English speakers, we studied 989 Chilean mothers from households of low socioeconomic status and their prekindergarten children, posing 2 questions: (a) Do mothers' self-reported practices about literacy development predict early literacy outcomes over and…

The Teacher Incentive Fund (TIF) provides grants to support performance-based compensation systems for teachers and principals in high-need schools. The study measures the impact of pay-for-performance bonuses as part of a comprehensive compensation system within a large, multisite random assignment study design. The treatment schools were to…

The Teacher Incentive Fund (TIF) provides grants to support performance-based compensation systems for teachers and principals in high-need schools. The study measures the impact of pay-for-performance bonuses as part of a comprehensive compensation system within a large, multisite random assignment study design. The treatment schools were to…