Growth-to-Proficiency and Student Poverty: A National Landscape Analysis
By: Collin Hitt, Ph.D., Courtney Vahle, Ed.D., Lucas Koch, and Andrew Camp, Ph.D.
Missouri schools will soon receive state ratings on an A–F scale. For K–8 schools, those grades will be based entirely on test score performance: two existing measures—proficiency and value-added growth—plus a new measure called “growth-to-proficiency” will be combined to create the A–F grades.
Several states already use growth-to-proficiency measures, although each applies a different formula. Missouri is still developing the methodology it will use.
This brief examines data from 8 states that use growth-to-proficiency models and an additional 5 states that use related value-table approaches. We explore a pivotal question: How are schools’growth-to-proficiency scores related to student poverty?
Key Points:
This question is especially important for anticipating how the new measure will compare with Missouri’s existing value-added model, which will also be used in the A-F rating system. The Missouri value-added Growth Model is best in class: its estimates of schools’ value-added impact show no relationship with student poverty, and unlike other measures has been validated to capture schools’ true impacts on learning.
Across every state we examine, in both ELA and math, growth-to-proficiency scores fall as student poverty rises. Put plainly, the measures are regressive: the GTP correlations averaged approximately -0.343 in ELA and -0.340 in math. Note that two states, Louisiana and Michigan have a single growth metric for ELA and math, whose correlations were -0.352 and -0.459, respectively.
This stands in stark contrast to results from Missouri's existing value-added, where the relationship between student growth estimates and student poverty is 0.031 for ELA and 0.034 for math. In many states, the correlation between GTP scores and poverty more closely resembles the correlation we see in Missouri between proficiency and student poverty.
If Missouri is going to adopt a model that matches its value-added model in rigor, while fairly treating schools that enroll high percentages of low-income children, it will need to develop a GTP model of its own.
Please Cite As: Hitt, C., Vahle, C., Koch, L., & Camp, A. (2026). Growth-to-Proficiency and Student Poverty: A National Landscape Analysis. Policy Research in Missouri Education, 8(9). www.primecenter.org/education-reports-database/growth-to-proficiency