Cluster randomized trials (CRTs) are commonly used to evaluate the causal effects of educational interventions, where the entire clusters (e.g., schools) are randomly assigned to treatment or control conditions. This study introduces statistical methods for designing and analyzing two-level (e.g., students nested within schools) and three-level…

Cluster randomized trials (CRTs) are commonly used to evaluate educational interventions, particularly their effectiveness. Recently there has been greater emphasis on using these trials to explore cost-effectiveness. However, methods for establishing the power of cluster randomized cost-effectiveness trials (CRCETs) are limited. This study…

Cost-effectiveness analysis is a widely used educational evaluation tool. The randomized controlled trials that aim to evaluate the cost-effectiveness of the treatment are commonly referred to as randomized cost-effectiveness trials (RCETs). This study provides methods of power analysis for two-level multisite RCETs. Power computations take…

Research Findings: This study compared the effects of content-based shared book-reading instruction versus an explicit vocabulary-only condition on the vocabulary development of preschool dual language learners (DLLs). Using shared book reading as the mode of instruction, we randomly assigned 48 bilingual preschool teachers and 281…

The purpose of the study was to explore the effectiveness of a brief, feasible, and cost-effective universal screener for kindergarten readiness. The study examined whether teacher ratings of kindergarteners' academic, behavioral, and overall readiness at the beginning of the year were predictive of academic, emotional, and behavioral outcomes at…