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Improvements in students’ writing scores related to CommonLit use
Study demonstrates a relationship between CommonLit use and student writing growth
A study of students’ writing growth at 22 research partner schools in three states during the 2022-2023 school year showed promising results. Findings revealed a positive relationship between middle school students’ CommonLit 360 usage and their writing growth – as scored by an independent evaluator, Measurement, Inc. In other words, the more CommonLit 360 lessons students completed, the more they tended to grow in their writing skills from the beginning to the end of the year. The study also found that the relationship between CommonLit 360 usage and writing growth was not significantly different for students at Title I eligible and Title I ineligible schools. Overall, the results show a promising relationship between CommonLit 360 usage and student writing growth for middle schoolers. This study was validated as meeting ESSA Tier 3 (“Promising Evidence”) standards by Instructure, a third-party ed tech research company.
Study Details
As part of their CommonLit 360 ELA instruction, Grade 6-8 students in 22 research partner schools completed CommonLit writing assessments at the beginning and end of the school year. Writing assessments were scored by an independent evaluator – Measurement, Inc. Specifically, anonymized essays were submitted to Measurement, Inc for their automated essay scoring process, referred to as MI Write. Essays were scored on six writing traits: conventions, ideas, organization, structure, style, and word choice. Trait scores ranged from 1 to 5 and may be summed to a total score, which can range from 6 to 30.
About the Sample
The study sample included 1,895 students, 84% of whom were enrolled in 21 schools eligible to receive Title I funding. Of the sample, 46% were enrolled in Grade 6 (n = 866), 36% in Grade 7 (n = 686), and 18% in Grade 8 (n = 343). Of the students with available demographic data, 49% self-identified as male, 45% as female, 2% as non-binary, and 3% preferred not to say. Of the students with demographic data, 38% self-identified as White, 24% Hispanic, 23% Black or African American, 10% Asian, 7% Multiracial, 2% American Indian or Alaska Native, 1% Middle Eastern, <1% Pacific Islander, and 5% preferred not to say. Self-reported language spoken at home was 85% English, 9% Spanish, 1% English and Spanish, and 5% other languages.
Key Finding #1: Students experienced significant writing growth
Students’ writing scores on CommonLit writing assessments significantly increased from the beginning of the school year to the end of the school year. Students’ average writing score at the beginning of the year was 13.40 (range = 6.00 - 27.05). At the end of the year, students’ average writing score was 15.55 (range = 6.00 - 29.00). This growth can be translated into an effect size, which is a standardized measure that conveys the magnitude of an effect. The effect size for students’ average writing growth in this study was Cohen’s d = 0.49. In education research, effect sizes larger than d = .20 are considered to be large, although correlational studies like this one tend to produce larger effect sizes than causal studies (such as a randomized controlled trial; Kraft, 2020). Figure 1 displays the average writing growth and effect size for average writing growth.

When examining writing growth for each grade level, results showed that students in each grade level experienced significant writing growth. Specifically, Grade 6 students went from an average of 13.83 (range = 6.00 - 25.45) to an average of 16.61 (range = 6.00 - 29.00), with an effect size of d = 0.63. Grade 7 students went from an average of 12.76 (range = 6.00 - 27.05) to an average of 14.39 (range = 6.00 - 26.68), with an effect size of d = 0.37. Grade 8 students went from an average of 13.60 (range = 6.00 - 26.98) to an average of 15.21 (range = 6.00 - 26.87), with an effect size of d = 0.38. Figure 2 displays the average writing growth and effect sizes by grade.

When examining writing growth for each of the six writing traits (conventions, ideas, organization, structure, style, and word choice), results showed that students’ writing growth was significant for each writing trait (d’s = 0.44 - 0.49). Figure 3 displays the average writing growth and effect sizes by trait. In sum, significant writing growth was observed for all grade levels and for all writing traits.

Key Finding #2: Writing growth was significantly related to CommonLit usage
Key Finding #1 demonstrated that students in this sample experienced significant writing growth on average. An important question is whether this writing growth was related to students’ use of the CommonLit 360 curriculum. Indeed, results showed that students’ writing growth was significantly related to their CommonLit 360 usage. There was a positive relationship between the number of CommonLit 360 lessons students experienced and their writing growth from beginning to end of the year. This relationship was statistically significant, even after controlling for important influences, such as baseline writing scores, grade level, Title I eligibility, and teacher effects. In other words, the more students used CommonLit 360, the more they tended to grow in their writing abilities. On average, students in this sample experienced 58 CommonLit 360 lessons.
For more information about the study, see the technical report.
CommonLit is evidence-based
Studies like this one that show exciting writing gains for students in CommonLit classrooms 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 certifications.
About CommonLit
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. Ed Reports recently rated CommonLit 360 as all-green, or “meets expectations”, as a quality curriculum. 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.
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References
Kraft, M. A. (2020). Interpreting effect sizes of education interventions. Educational Researcher, 49(4), 241-253.