We report the results of a preregistered, cluster randomized controlled trial of a mathematics learning intervention known as interleaved practice. Whereas most mathematics assignments consist of a block of problems devoted to the same skill or concept, an interleaved assignment is arranged so that no 2 consecutive problems require the same…

We explore the conditions under which short, comparative interrupted time-series (CITS) designs represent valid alternatives to randomized experiments in educational evaluations. To do so, we conduct three within-study comparisons, each of which uses a unique data set to test the validity of the CITS design by comparing its causal estimates to…

We report the results of a pre-registered, cluster randomized controlled trial of a mathematics learning intervention known as interleaved practice. Whereas most mathematics assignments consist of a block of problems devoted to the same skill or concept, an interleaved assignment is arranged so that no two consecutive problems require the same…

Research Findings: This study reports outcomes from a randomized, controlled trial of an emergent literacy intervention for prekindergarten children at-risk for reading failure. Children (N = 2219) in 114 preschools and childcare centers were screened for eligibility in fall. Children who scored at-risk (n = 476) were randomized to fall or spring…

More than 20 percent of all school-aged children in the United States have vision problems, and low-income and minority children are disproportionately likely to have unmet vision care needs. Vision screening is common in U.S. schools, but it remains an open question whether screening alone is sufficient to improve student outcomes. We implemented…

This randomized controlled trial in 55 low-performing schools across Florida compared 2 early literacy interventions--1 using stand-alone materials and 1 using materials embedded in the existing core reading/language arts program. A total of 3,447 students who were below the 30th percentile in vocabulary and reading-related skills participated in…

Large numbers of qualified students do not apply to and enroll in college. Yet, earning a college degree is one of the primary pathways for economic success and is increasingly required for good jobs and high wages. A number of programs and practices aim to improve college readiness and enrollment, including "Take Stock in Children's®…

Understanding written language is crucial to academic success in all content areas. Ensuring a strong foundation in the components of written language--that is, the literacy skills of reading, writing, and oral language--is essential if students are to read with understanding and, thus, is a primary goal of early literacy instruction and of the…

This randomized controlled trial in 55 low-performing schools across Florida implemented two literacy interventions--one using a standalone intervention and one using materials embedded in the core reading program. The interventions were delivered daily for 45 minutes for 27 weeks in 2013/14 and 2014/15 in small groups of K-2 students at risk of…

This randomized controlled trial in 55 low-performing schools across Florida compared 2 early literacy interventions--1 using stand-alone materials and 1 using materials embedded in the existing core reading/language arts program. A total of 3,447 students who were below the 30th percentile in vocabulary and reading-related skills participated in…

The objective of this article is to describe seven elements important to successful implementation of early literacy intervention. The seven elements are drawn from research as well as from the authors' recent randomized controlled trial of effective early literacy interventions in kindergarten through second grade in 55 schools across Florida.…

An extensive body of research demonstrates a higher prevalence of obesity among children with developmental delays (DD) versus children without delays. This analysis examined the effectiveness of a randomized controlled trial to promote healthy weight in a subsample of preschool-age children with DD (n = 71) on the adoption of quality nutrition…

Background: One in four preschool-age children in the United States are currently overweight or obese. Previous studies have shown that caregivers of this age group often have difficulty accurately recognizing their child's weight status. The purpose of this study was to examine factors associated with accurate/inaccurate perception of child body…

Randomized experiments have long been established as the gold standard for addressing causal questions. However, experiments are not always feasible or desired, so observational methods are also needed. When multiple observations on the same variable are available, a repeated measures design may be used to assess whether a treatment administered…

Objective: This is a replication of a study that examined the effects of teaching foundation competencies in group work to social work students and assessed their self-confidence in applying these skills. This study improves on the first by utilizing a controlled design. Method: Twenty-six master of social work students were taught group work…