Recent reviews of the educational intervention literature have noted patterns of intervention impact fadeout on cognitive skills, whereby skill trajectories between children in the intervention and control group converge in the years following the end of the intervention. Some early childhood education (ECE) researchers have suggested that skill…

High-quality preschool programs are heralded as an effective policy tool to promote the development and life-long wellbeing of children from low-income families. Yet evaluations of recent preschool programs produce puzzling findings, including negative impacts, and divergent, weaker results than were shown in demonstration programs implemented in…

Plausible competing developmental models show similar or identical structural equation modeling model fit indices, despite making very different causal predictions. One way to help address this problem is incorporating outside information into selecting among models. This study attempted to select among developmental models of children's early…

We present findings across three randomized trials of "Descubriendo la Lectura" (DLL), an intervention designed to improve literacy skills of Spanish-speaking first graders struggling with reading. DLL is a one-to-one Spanish-language literacy program lasting 12-20 weeks offered to a school's lowest performing emerging bilingual first…

Identifying effective methods that can counteract seasonal trends in learning loss is essential to ensure continuous literacy growth of young learners. Computer-assisted instruction (CAI) is a solution for providing an effective summer literacy program that could help offset summer learning loss. In this study, four-year-old students from South…

There is a need for robust evidence about which educational interventions work in preschool to foster children's cognitive and socio-emotional learning (SEL) outcomes. Lab-based individually randomized experiments can develop and refine such interventions, and field-based randomized experiments (e.g., cluster randomized trials) evaluate their…

Analyzing heterogeneous treatment effects (HTEs) plays a crucial role in understanding the impacts of educational interventions. A standard practice for HTE analysis is to examine interactions between treatment status and preintervention participant characteristics, such as pretest scores, to identify how different groups respond to treatment.…

In this article, Rachel Abenavoli, Natalia Rojas, Rebecca Unterman, Elise Cappella, Josh Wallack, and Pamela Morris argue that research-practice partnerships make it possible to rigorously study relevant policy questions in ways that would otherwise be infeasible. Randomized controlled trials of small-scale programs have shown us that early…

In this article, Rachel Abenavoli, Natalia Rojas, Rebecca Unterman, Elise Cappella, Josh Wallack, and Pamela Morris argue that research-practice partnerships make it possible to rigorously study relevant policy questions in ways that would otherwise be infeasible. Randomized controlled trials of small-scale programs have shown us that early…

Analyzing heterogeneous treatment effects (HTE) plays a crucial role in understanding the impacts of educational interventions. A standard practice for HTE analysis is to examine interactions between treatment status and pre-intervention participant characteristics, such as pretest scores, to identify how different groups respond to treatment.…

Longitudinal models of individual growth typically emphasize between-person predictors of change but ignore how growth may vary "within" persons because each person contributes only one point at each time to the model. In contrast, modeling growth with multi-item assessments allows evaluation of how relative item performance may shift…

Longitudinal models typically emphasize between-person predictors of change but ignore how growth varies "within" persons because each person contributes only one data point at each time. In contrast, modeling growth with multi-item assessments allows evaluation of how relative item performance may shift over time. While traditionally…

Background: The language of the science curriculum is complex, even in the early grades. To communicate their scientific observations, children must produce complex syntax, particularly complement clauses (e.g., "I think it will float;" "We noticed that it vibrates"). Complex syntax is often challenging for children with…

This paper reviews research on the design and effectiveness of preschools in the United States. Three randomized controlled trials that enrolled roughly 350 total children in demonstration studies during the 1960s and 1970s shape much of the current discussion of preschool. We examine what these studies and more recent ones based on random…

Context: Assessments of baseline equivalency of intervention and control groups, "balance," play a critical role in evaluating educational interventions. The highest What Works Clearinghouse (WWC) of the Institute of Educational Studies (IES) standard for educational studies, "Meets WWC Design Standards Without Reservations,"…