The Associated Effects of McGraw Hill's Wonders Program on Measures of Achievement and Teacher Attitudes

This study examined the impact of the Wonders reading program on 299 students in grades K-5 at one elementary school in Wisconsin over the 2018-2019 and 2019-2020 school years. The school was predominantly Caucasian (96%), with 41% of students receiving free or reduced-price meals. The study used a longitudinal design, analyzing student performance on Renaissance STAR Reading and STAR Early Literacy benchmark assessments. For the 5th-grade cohort, scores on the Wisconsin Forward state exam were also analyzed. Results showed positive gains across multiple grade levels. First graders demonstrated a statistically significant median percentile increase from 49 to 82 during the second year of implementation. Second and third graders also showed significant gains in median percentile rank during the first year of implementation (14 units each). Fifth graders showed significant gains on the Wisconsin Forward exam after one year of Wonders use, with the mean score increasing by 44 points and the percentage of students scoring Proficient or above rising from 6% to 36%. The effect size for this gain was large (d=1.18).