Discipline-based education researchers have a natural laboratory--classrooms, programs, colleges, and universities. Studies that administer treatments to multiple sections, in multiple years, or at multiple institutions are particularly compelling for two reasons: first, the sample sizes increase, and second, the implementation of the treatments…

This study uses data from a comprehensive database of U.S. early childhood education program evaluations published between 1960 and 2007 to evaluate the relationship between class size, child-teacher ratio, and program effect sizes for cognitive, achievement, and socioemotional outcomes. Both class size and child-teacher ratio showed nonlinear…

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.…

Students' interest in science declines in secondary school. Therefore, motivating students to become competent and engaged in science topics that are relevant for their everyday lives is an important goal, so they can be better citizens and decision makers with socioscientific issues (e.g., climate change and waste disposal). The present study…

Purpose: The current study used an intervention design to test the hypothesis that parent input sentences with diverse lexical noun phrase (NP) subjects would accelerate growth in children's sentence diversity. Method: Child growth in third person sentence diversity was modeled from 21-30 months (n = 38) in conversational language samples obtained…

The purpose of this study is to assess how studying abroad impacts the development of intercultural competence and the moderating role of student's personality. This research uses a pre-post design with a sample of 264 undergraduate students from four Colombian universities; it includes a group of students who participated in a one semester…

National efforts to transform undergraduate biology education call for research experiences to be an integral component of learning for all students. Course-based undergraduate research experiences, or CUREs, have been championed for engaging students in research at a scale that is not possible through apprenticeships in faculty research…

We investigated methods of including covariates in two-level models for cluster randomized trials to increase power to detect the treatment effect. We compared multilevel models that included either an observed cluster mean or a latent cluster mean as a covariate, as well as the effect of including Level 1 deviation scores in the model. A Monte…

Genetic liability to autism spectrum disorder (ASD) can be expressed in unaffected relatives through subclinical, genetically meaningful traits, or endophenotypes. This study aimed to identify developmental endophenotypes in parents of individuals with ASD by examining parents' childhood academic development over the school-age period. A cohort of…

We describe the application of Hierarchical Linear Modelling (HLM) in a cluster-randomised study to examine learning algebraic concepts and procedures in an innovative, technology-rich environment in the US. HLM is applied to measure the impact of such treatment on learning and on contextual variables. We provide a detailed description of such…

In Belize, the percentage of untrained teachers (i.e. teachers with the equivalent of a high school education or less) is one of the highest in the region of Latin America and the Caribbean. In response to growing student cohorts, the increased demand for more classroom teachers has led to significant decrease in the proportion of trained teachers…

A study was conducted in 26 Head Start classrooms with 264 children to compare the effect of a read aloud plus extension activities intervention over a control group to the effect of a read aloud only intervention over a control group on preschool children's vocabulary. Children were assessed before and after the intervention on target vocabulary…