Educational Effects of a Vocabulary Intervention on Preschoolers' Word Knowledge and Conceptual Development: A Cluster‐Randomized Trial

The purpose of this study was to examine the hypothesis that helping preschoolers learn words through categorization may enhance their ability to retain words and their conceptual properties, acting as a bootstrap for self‐learning. We examined this hypothesis by investigating the effects of the World of Words instructional program, a supplemental intervention for children in preschool designed to teach word knowledge and conceptual development...