Raz-Plus Efficacy Study Shows Usage in First Grade Associated With Accelerated Growth
About this research
This study evaluated the impact of Raz-Plus® on first-grade reading growth over a 16-week period. Using a quasi-experimental design that meets ESSA Tier 2 (Moderate) evidence standards, researchers compared reading outcomes for 4,602 students in classrooms with high, consistent Raz-Plus implementation and students in classrooms with minimal usage. Results showed that students using Raz-Plus demonstrated significantly greater reading growth, exceeded national growth expectations, and experienced measurable instructional advantages. The greatest benefits were observed among students entering the year below the 25th percentile, highlighting Raz-Plus's ability to support striving readers and help close literacy gaps.
ESSA Evidence
ESSA Evidence Level: Moderate
This study meets moderate evidence standards because it used a well-designed quasi-experimental design with baseline-equivalent treatment and comparison groups. Researchers statistically controlled for pre-existing differences and found positive effects associated with consistent Raz-Plus implementation on student reading growth.
Main Findings
Students in classrooms with consistent Raz-Plus implementation achieved significantly greater reading growth than similar peers with minimal usage. Students using Raz-Plus gained an adjusted 8.75 RIT points, compared to 8.07 RIT points for the comparison group, representing approximately 1.6 additional weeks of reading instruction. Raz-Plus students also exceeded typical national NWEA MAP® growth expectations by 10%. Students entering the year below the 25th percentile demonstrated the largest gains, achieving a 2.6-week instructional advantage over similar peers.
Participants
Participants were 4,602 first-grade students across 123 schools and 267 classrooms. The treatment group included 1,870 students in classrooms with high, consistent Raz-Plus use, while the comparison group included 2,732 students in classrooms with minimal Raz-Plus usage.
Study Design and Procedures
This study used a quasi-experimental design (QED) to compare reading growth among students in classrooms with high levels of Raz-Plus implementation and students in classrooms with limited use of the solution. Reading achievement was measured using the NWEA MAP Growth Reading assessment between fall and winter testing periods and standardized to a 16-week growth window. Researchers used hierarchical linear modeling to account for student, classroom, and school-level factors and conducted additional analyses to examine outcomes for students with varying levels of academic risk.
Citations
The Harris Poll (2025). Nemours Children’s Reading BrightStart! Early Literacy Survey: A National Survey by Nemours Children’s Health. {Unpublished Report] https://www.nemours.org/content/dam/nemours/nemours-org/en/documents/NCRBS-harris-poll-executive-summary.pdf
Kuhfeld, M., Lewis, K., Morton, E. (2026, June). Behind at the starting line: What Kindergarten test scores tell us about reaching proficiency in 3rd grade (Research Brief). NWEA Research. Retrieved from https://www.nwea.org/uploads/Behind-the-starting-line-what-kindergartent-test-scores-tell-us-about-reaching-proficiency-in-third-grade_NWEA_researchBrief.pdf
National Center for Education Statistics. (2017). The Nation's Report Card: NAEP Reading 2017 Assessment. U.S. Department of Education, Institute of Education Sciences. https://www.nationsreportcard.gov/
National Center for Education Statistics. (2024). The Nation's Report Card: NAEP Reading 2024 Assessment. U.S. Department of Education, Institute of Education Sciences. https://www.nationsreportcard.gov/
Vaknin-Nusbaum, V., Nevo, E., Brande, S., & Gambrell, L. (2018). Developmental aspects of reading motivation and reading achievement among second grade low achievers and typical readers. Journal of Research in Reading, 41(3), 438–454. https://doi.org/10.1111/1467-9817.12117
