Investigating the Impacts of Science of Reading High Quality Instructional Materials Across Multiple Contexts

This study investigates the implementation and efficacy of a high-quality instructional material (HQIM) grounded in the science of reading—Really Great Reading (RGR)—across five diverse educational contexts. Employing both quasi-experimental and correlational research designs, the study evaluates RGR's impact on student literacy outcomes in early and upper elementary grades. Data were collected from over 2,600 students in urban, suburban, and rural school settings across the United States. Findings consistently demonstrated positive associations between RGR usage and improved reading achievement, especially in foundational skills such as phonemic awareness, phonics, and fluency. Statistically significant gains were observed in kindergarten and early grade students, including those from historically marginalized groups. Notably, the study found evidence of sustained improvement into subsequent academic years, suggesting long-term benefits of RGR-aligned instruction. Results reinforce the importance of structured literacy programs and support the use of HQIM aligned with the science of reading to improve early literacy outcomes.