Although professional development is widely used to improve the impacts of early childhood education, little is known about the conditions under which such interventions promote child outcomes. This study applies newly developed methods for quantifying intervention impact heterogeneity to understand whether educators' collective workplace stress…

Examined the use by children of the Novel Name-Nameless Category principle, under the framework that lexical principles are acquired in a developmental sequence. Results indicated that the particular principle was not available at the start of lexical acquisition but that exhaustive categorization ability and a vocabulary spurt occur…