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…

As the number of publicly funded early childhood education (ECE) programs increases, policymakers will need empirical evidence to justify the taxpayer investment. Such justification will require a stronger understanding of the essential components of an ECE program's design, as well as solid evidence on which components, or constellations of…