May, HenryStrong, John Z.Walpole, Sharon2024-02-142024-02-142023-12-03Henry May, John Z. Strong & Sharon Walpole (2023) The Effects of Bookworms Literacy Curriculum on Student Achievement in Grades 2-5, Scientific Studies of Reading, DOI: 10.1080/10888438.2023.22848111532-799Xhttps://udspace.udel.edu/handle/19716/33990This article was originally published in Scientific Studies of Reading. The version of record is available at: https://doi.org/10.1080/10888438.2023.2284811. © 2023 The Author(s). Published with license by Taylor & Francis Group, LLC. This research was featured in UDaily on 7/9/2024, available at: https://www.udel.edu/udaily/2024/july/bookworms-student-outcomes-literacy-reading-elementary-school/Purpose In this study, we investigated the effects of a schoolwide program, Bookworms K-5 Reading and Writing, on student achievement. Method The study included seven cohorts of students (N = 8,806) in grades 2–5 in 17 elementary schools across three school years. We used a comparative interrupted time-series design, conducting multilevel growth curve models of Measures of Academic Progress reading scores with up to 10 data points per student. By modeling each student’s growth curve, including a time by treatment interaction term, we were able to estimate the change in students’ achievement trajectories corresponding to the implementation of Bookworms. Results Results confirm a significant positive impact of Bookworms on achievement, with gains compounding over time and producing an overall standardized effect size of .26 by the end of 5th grade. Students who began third grade with relatively weaker achievement experienced more growth than those with average achievement, and those with average achievement experienced more growth than those with the highest achievement. Conclusion This study provides evidence that a comprehensive literacy curriculum that emphasizes high-volume reading of grade-level texts and the use of evidence-based instructional practices produces positive effects on student achievement for students with a range of initial reading achievement.en-USAttribution-NonCommercial-NoDerivatives 4.0 InternationalArticle