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…

UNICEF's new Millennium Development Goals and Beyond (2015. http://www.un.org/millenniumgoals/) focus on the needs of the largest marginalised minority, individuals with disabilities, challenging us to examine issues related to exclusion and develop strategies for making an authentic sense of belonging and high-quality early childhood education a…

Based on a one-year longitudinal experimental study with 3,782 kindergarten school children across 15 countries, this article examines the association between prayer and happiness. Results show that the post-test scores on the faces scale were higher for the participant group who had taken the prayer lessons vis-à-vis the comparison group.…

Children from low-income and ethnic minority backgrounds have demonstrated substantially lower levels of math achievement than their middle class majority peers for decades. The present study addressed two research questions: (1) when used as a supplement to typical classroom instruction and in isolation from the larger curriculum, does Building…

This study used a randomized controlled trial design to investigate the ROOTS curriculum, a 50-lesson kindergarten mathematics intervention. Ten ROOTS-eligible students per classroom (n = 60) were randomly assigned to one of three conditions: a ROOTS five-student group, a ROOTS two-student group, and a no-treatment control group. Two primary…

Although evidence of negative associations between early literacy development and children's behavior problems exists, the field still lacks an understanding of the complicated links between these two areas. Children's gender has often not been included in much of the extant research as a potential moderating variable, yet gender differences may…

Results from a cluster randomized trial of the impact of the Tools of the Mind pre-kindergarten curriculum on preschoolers' achievement, self-regulation, and social behavior are reported. Sixty classrooms with four-year-old children (N=877) were assigned to implement either the Tools curriculum (N=32 classrooms; 498 children) or the usual pre-k…

"Un Buen Comienzo" [A Good Start] was a professional development program implemented with prekindergarten and kindergarten teachers in Chilean public schools serving low-income families. In a randomized trial, the program showed moderate to large impacts on classroom quality but no impacts on targeted child outcomes. To unpack these…