This study is a randomized control trial of full- versus half-day prekindergarten (pre-K) in a school district near Denver, Colorado. Four-year-old children were randomly assigned an offer of half-day (4 days/week) or full-day (5 days/week) pre-K that increased class time by 600 hours. The full-day pre-K offer produced substantial, positive…

Problem/Purpose: Young children with developmental speech and/or language impairment (DSLI) often fail to develop important oral language and early literacy skills that are foundational for subsequent schooling and reading success. The purpose of this investigation was to examine the efficacy of the TELL curriculum and associated evidence-based…

The purpose of this cluster randomized group study was to investigate the effect of multitiered, dual-language instruction on children's oral language skills, including vocabulary, narrative retell, receptive and expressive language, and listening comprehension. The participants were 3- to 5-year-old children (n = 81) who were learning English and…

This paper reports the fifth-year results of a study comparing the English and Spanish language and reading performance of Spanish-dominant children randomly assigned beginning in kindergarten to Transitional Bilingual Education (TBE) or Structured English Immersion (SEI). This is the first randomized study to compare TBE and SEI reading…