1. Mathematics Growth
Portrayals of mathematics growth for students with disabilities (SWD) can vary depending on how special education membership is defined. This graph depicts mean achievement at each grade when three three different ways of defining special education membership are used. The Wave 1 and Ever in Special Education groups are formed longitudinally, so that the same group of students are followed across all grades. The Wave 1 SWD group consists of students who were in special education when they were in third grade. The Ever in Special Education group consists of any student who was in special education some time during grades three to eight. The Current Year in Special Education means are calculated from a group that changes each year, as students enter and exit special education. When a stable group of students is followed across grades, growth appears more robust for students in special education than when cross sectional means are used to depict growth. The different definitions produce nearly identical outcomes for students who are not in special education. Regardless of how special education membership is defined, students in special education lag behind their same-grade peers in mathematics achievement, but the extent to which they lag behind depends on how the group is defined.