State Policy Center: Ensuring All Students Count: The Minimum N-Size Education Data Act
Our education system is only effective if it is effective for all students.
But the only way to know if it is effective for all students is for all students to be included in the accountability system. States must set a minimum number of students to be used when disaggregating data for the purpose of reporting student performance to the public and identifying schools for support. This number, commonly referred to as the “n-size,” must be large enough to avoid revealing personally identifiable information about students and yield statistically reliable information. However, it should also be small enough to ensure the performance of students who have been historically marginalized is fully represented in states’ systems for accountability and reporting.
States have chosen to set their n-size as low as five students and as high as 30. By selecting a low n-size, many states have been able to make their accountability systems more equitable by increasing the number of schools held accountable for the results of individual student groups, even if the school has smaller enrollment numbers. For example, by selecting an n-size of 20 instead of 30, one state increased the number of schools included in its accountability system based on individual student group data by 653, an increase of nearly 10%. As a result, parents and the public have richer information about student performance at the schools, including potential gaps in achievement, progress, graduation, and readiness, and these schools can access additional resources to support school improvement. An effective accountability system will have an n-size as low as five in order to include data on as many students as possible and provide them with support as needed.
Model PolicY
The Minimum N-Size Education Data Act: Maximally Inclusive Numbers Improve Measurement, Understanding, and Meaning in Education Data Act
Click HERE to download
Supporting Documents
In 36 states, the academic needs of large numbers of Black and Latino students, students from low-income families, English learners, students with disabilities, and other groups of historically underserved students may be ignored, because the state accountability system fails to include these student subgroups.
Click HERE to read more.
Featured Resources

Ensuring Equity in ESSA: The Role of
N-Size in Subgroup Accountability

Too Many States Minimize Student Subgroup Performance in Accountability Systems
