More of the variance in linear growth lies at the school level for fall-to-spring than for spring-to-spring estimates, in some cases twice or three times as much¶

Claim · All claims
Evidence · 1 study · associational r2 · q2
Currency · newest study 2019 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? Across models and subjects, ICCs show more variance in linear growth is at the school level for within-year than between-year growth; for reading centered at second grade, three times as much variance is at the school level for fall-to-spring growth. → Soland 2019

Evidence¶

Soland 2019¶

Soland, J. & Thum, Y.M. (2019). School effectiveness, summer loss, and federal accountability: Applying the compound polynomial model in a program evaluation context. The Collaborative for Student Growth at NWEA Working Paper. https://www.nwea.org/research/publication/school-effectiveness-summer-loss-and-federal-accountability-applying-the-compound-polynomialmodel-in-a-program-evaluation-context/

q2 · i? · associational · r2

Intraclass correlation coefficients computed from the school- and student-level variance components of CP models (Table 3), including linear-only adaptations omitting the quadratic terms. The article reports the three-times result for reading centered at second grade.

"These ICCs suggest that, across models and subjects, more of the variance in linear growth is at the school level when estimates use within-year rather than between-year growth. Differences are most pronounced when the models do not include quadratic terms. For example, for reading centered at second grade, three times as much of the variance is at the school level for fall-to-spring growth than spring-to-spring."

Discussion¶

Related Claims¶

• Nearly half the variance in kindergarten-entry scores lies between districts, with less variance in achievement trends at the district level — related
• Within-year (fall-to-spring) achievement gains decelerate linearly as students move through school, at roughly 1.4 to 4 RIT per year depending on subject and centering grade — related
• Over a quarter of variance in student growth lies at the school level, and 12-16% of schools significantly overperform average growth — related
• Classroom-level ICCs for elementary test score gains range from 0.02 to 0.15 and school-level ICCs from 0.05 to 0.20, so classroom effects explain about 15 percent of gain-score variance — related
• Rapid guessing had mostly minimal effects on estimates of school contributions to student growth in this sample — related
• In the study data, mean spring grade-2 math RIT was 190.6 with linear spring-to-spring growth of 14.5 RIT, and mean fall-to-spring gain in grade-2 math was 13.4 RIT — related
• Within-year fall-to-spring gains are largest in second grade (about 13.4 RIT in math) and slow by roughly 1.4 RIT per year as students progress through elementary school — related
• Assuming linear within-year achievement growth is often not justified, particularly in reading — related