A Multisite Randomized Controlled Trial of the Effectiveness of Descubriendo la Lectura

We present findings from a randomized controlled trial of Descubriendo la Lectura (DLL), an intervention designed to improve the literacy skills of Spanish-speaking first graders, who are struggling with reading. DLL offers one-on-one native language literacy instruction for 12 to 20 weeks to each school’s lowest performing first-graders. Examining literacy outcomes for 187 students, hierarchical linear model analyses revealed statistically significant effects of student-level assignment to DLL on all 9 outcomes evaluated. Impacts were as large as 1.24 standard deviations, or a learning advantage relative to controls exceeding a full school year of achievement growth. The mean effect size of d = 0.66 across the nine literacy measures is equal to approximately two thirds of the overall literacy growth that occurs across the first-grade year.

Addressing Literacy Needs of Struggling Spanish-Speaking First Graders: First-Year Results From a National Randomized Controlled Trial of Descubriendo la Lectura

Given the growing number of Latino English learners and the lack of evidence-based educational opportunities they are provided, we investigated the impact of one potentially effective literacy intervention that targets struggling first-grade Spanish-speaking students: Descubriendo La Lectura (DLL). DLL provides first-grade Spanish-speaking students one-on-one literacy instruction in their native language and is implemented at an individualized pace for approximately 12 to 20 weeks by trained bilingual teachers. Using a multisite, multicohort, student-level randomized controlled trial, we examined the impact of DLL on both Spanish and English literacy skills. In this article, we report findings from the first of three cohorts of students to participate in the study. Analyses of outcomes indicate that treated students outperformed control students on all 11 Spanish literacy assessments with statistically significant effect sizes ranging from 0.34 to 1.06. Analyses of outcomes on four English literacy assessments yielded positive effect sizes, though none were statistically significant.