Falling Below the Line: Minimum Subgroup Size and Special Education Enrollment

The No Child Left Behind Act of 2001 (NCLB) brought high-stakes accountability testing into every American public school with the goal of 100 percent proficiency for all students. Making annual yearly progress (AYP) toward this proficiency goal for the total student population as well as at-risk subgroups was required in order for schools to avoid possible sanctions, such as school restructuring. In implementing NCLB, states had flexibility to determine the minimum size of these subgroups as to provide statistical reliability and accountability for as many schools as possible. If a school did not meet the state’s minimum subgroup size, the proficiency of the students in the group were not calculated as part of AYP. The subjectivity of identification along with the lack of reliability in test score results makes manipulating the subgroup of students with disabilities possible and advantageous to schools. Using data from over 1,000 Arkansas schools for the years 2004-05 to 2013-14, school-level fixed effects analyses show that falling below the minimum subgroup cutoff of 40 is associated with a 1.5 percentage point decrease in students with disabilities at the school. For every student a school is above the cutoff, there is an increase of 0.09 percentage points in special education enrollment. Possible implications are discussed.