A new evaluation of CommonLit shows significantly higher reading growth for students in CommonLit classrooms
Exciting reading gains were observed in a recent study on CommonLit’s efficacy in 531 schools across the nation during the 2022-2023 school year. Compared to students who did not use CommonLit, students in CommonLit classrooms observed significantly higher reading gains of 2-6 additional months of learning. This can be translated into a 24-62% improvement over their annual expected reading gains. In terms of assessment performance, students in CommonLit classrooms saw major growth, with increases in proficiency between 13-25%. These findings demonstrate the promise of CommonLit for supporting students’ academic achievement.
This study examined the reading growth of students who completed the CommonLit Assessment Series at the beginning and end of the school year. The study sample included a total of 116,440 students in 6th-10th grade, taught by 2,202 teachers in 531 schools across the nation. Students were from schools with a research partnership or paid partnership with CommonLit. Based on NCES data, 47% of the schools in the sample received or were eligible to receive Title I funding in 2022-2023.
Key Finding #1: Students in CommonLit classrooms had significant reading growth of 2-6 additional months of learning
Results showed a clear relationship between the number of CommonLit lessons students experienced and their reading growth over the course of the school year. Across grade levels, students in CommonLit classrooms had significantly higher reading growth compared to students who did not use CommonLit (see Figure 1). Students in CommonLit classrooms used a variety of CommonLit’s educational resources, including the CommonLit 360 curriculum, supplemental lessons and Target Lessons in the library.
Figure 1. The graph shows the effect size of students’ reading growth over the school year in standard deviation units. Students in the “no usage” group did not experience any CommonLit lessons. Students in the other groups experienced 1-5, 6-10, 11-15, or 16+ lessons from the CommonLit 360 curriculum and/or the CommonLit Library. The graph also depicts the additional months of learning gained on average within each group, compared to the “no usage” group.
How did this reading growth translate into additional months of learning? Compared to students who did not use CommonLit…
- Students who experienced 1-5 CommonLit lessons gained an additional 2.2 months of learning on average – a 24% improvement over their expected annual reading gains.
- Students who experienced 6-10 CommonLit lessons gained an additional 4.2 months of learning on average – a 47% improvement over their expected annual reading gains.
- Students who experienced 11-15 CommonLit lessons gained an additional 5.6 months of learning on average – a 62% improvement over their expected annual reading gains.
- Students who experienced 16 or more CommonLit lessons gained an additional 5.6 months of learning on average – a 62% improvement over their expected annual reading gains.
Key Finding #2: Among students in CommonLit classrooms, there was a 13-25% increase in proficiency
Another indicator of reading growth is the change in the number of students who scored “Proficient” on a CommonLit Assessment at the beginning of the year compared to the end of the year. When comparing these numbers, there was a clear difference across groups of students (see Figure 2).
Figure 2. The graph shows the percent increase in students scoring “Proficient” from the beginning to the end of the year within each group. For more context, students' scores on the assessments may be categorized as “Proficient” (on grade level or above grade level) or “Not Proficient” (below/approaching grade level).
Among students who did not use CommonLit, there was only a 7% increase in proficiency. By contrast, students in CommonLit classrooms had higher percent increases in proficiency:
- Among students who experienced 1-5 CommonLit lessons, there was a 13% increase in proficiency.
- Among students who experienced 6-10 CommonLit lessons, there was a 16% increase in proficiency.
- Among students who experienced 11-15 CommonLit lessons, there was a 20% increase in proficiency.
- Among students who experienced 16 or more CommonLit lessons, there was a 25% increase in proficiency.
CommonLit is Evidence-Based
Studies like this one that show exciting reading gains for students in CommonLit classrooms in 531 schools across the country contribute to our growing evidence base of research and showcase the effectiveness of CommonLit. To ensure that CommonLit’s programs are aligned with the mission to close the literacy achievement gap, both external evaluators and researchers on CommonLit’s evaluation team are constantly monitoring student outcomes. CommonLit’s evidence-based approach directly supports districts by giving them confidence in our programs and by earning ESSA Tier III certification to allow them to use ESSER funding to bring CommonLit to their classrooms.
CommonLit offers several educational resources for teachers and schools. CommonLit 360 is CommonLit’s free English Language Arts program that includes a year-long curriculum, assessments, professional development, and data dashboards. CommonLit also offers a Library that includes a wide variety of standards-aligned texts as well as supplemental lessons and Target Lessons designed to support the learning needs of all students. To address inequities in access to technology in classrooms, CommonLit materials are available to teachers and students both online on the digital platform and offline as downloads. Previous research on CommonLit’s educational programs have found exciting results that consistently demonstrate reading growth in CommonLit classrooms.
Bloom, H. S., Hill, C. J., Black, A. R., & Lipsey, M. W. (2008). Performance trajectories and performance gaps as achievement effect-size benchmarks for educational interventions. Journal of Research on Educational Effectiveness, 1(4), 289-328.
Hill, C. J., Bloom, H. S., Black, A. R., & Lipsey, M. W. (2008). Empirical benchmarks for interpreting effect sizes in research. Child Development Perspectives, 2(3), 172-177.
Kraft, M. A. (2020). Interpreting effect sizes of education interventions. Educational Researcher, 49(4), 241-253.
1 The effect sizes and months of learning shown in this graph represent weighted averages based on the number of students within each grade and group.
2 For readers interested in how we translated effect sizes into months of learning: Within each grade level, we compared the reading growth of each level of usage (1-5, 6-10, 11-15, or 16+ lessons) to the reading growth of the “no usage” group. The difference in reading growth between these groups was compared to the expected annual reading gains based on benchmarks from seven nationally normed reading tests (Bloom et al., 2008; Hill et al., 2008). From there, a weighted average for months of learning was calculated for each group based on the number of students within each grade level. For more information on this method of translating effect sizes into meaningful units, see Kraft (2020).
3 For more information about how the performance categories were determined, see this support article.