Journal of Educational Psychology, Vol 117(2), Feb 2025, 153-175; doi:10.1037/edu0000916
This study examined the impact of a widely used content-rich literacy curriculum on kindergarteners’ vocabulary, listening comprehension, and content knowledge. In combined findings from two randomized controlled trials (RCTs), the second being a replication of the first, 47 schools in large urban U.S. districts were randomly assigned to implement Core Knowledge Language Arts: Knowledge Strand (CKLA: Knowledge) or to a waitlist control condition. CKLA: Knowledge focuses instruction on language comprehension through interactive read alouds that systematically build content knowledge. Teachers received two days of professional development workshops, along with light-touch support from facilitators during implementation. Participants included 1,194 kindergarten students, who were administered individual pre- and posttest measures of proximal and standardized vocabulary, listening comprehension, and content knowledge (i.e., science, social studies). After approximately one semester of curricular implementation, CKLA: Knowledge demonstrated positive and significant impacts on proximal vocabulary and science and social studies knowledge. Significant interactions were found for vocabulary and content knowledge, such that children who began the year with relatively higher receptive vocabulary scores derived a greater benefit of learning the words and content knowledge taught in the curriculum. The present work is unique in that it tested the effects of a content-rich literacy curriculum that integrated literacy and content-area instruction and replicated the effects across two RCTs. (PsycInfo Database Record (c) 2025 APA, all rights reserved)