Student Growth Percentile (SGP)
The Student Growth Percentile (SGP), developed by Dr. Damian Betebenner, provides the latest in growth projections, including Betebenner's well-known catch-up, keep-up growth projections to provide longitudinal SGP data.
SGP compares a student's growth to that of his or her academic peers nationwide. These peers are students in the same grade with a similar achievement history on Star assessments.
SGP is measured on a 1–99 scale. Lower numbers indicate lower relative growth, and higher numbers indicate higher relative growth. For instance, if a student has an SGP of 75, it means the student has shown more growth than 75 percent of his or her academic peers. Teachers and administrators can use SGP scores to determine if students grew more than, less than, or as much as expected.
SGP is calculated for students who have taken at least two tests within different testing windows. It uses the most recent test (within the past 18 months) and at least one prior test from an earlier testing window (Fall, Winter, or Spring; the dates for these windows are static and need not correspond to a school or district's school year). The calculation uses the first test in the Fall, the test closest to January 15 in Winter, and the last test in Spring.
SGP utilizes the historical growth trajectories of Star examinees to map out what the range of potential growth trajectories for each student will lead to, including what growth is necessary for each student to reach/maintain proficiency. SGP is updated regularly so that students projections are based upon the most recent data available.
Reports that have this score: Growth Report, Growth Proficiency Chart
Expected Growth for Special Education Students and ELLs: For the general population of students, a student growth percentile of 50 represents typical growth—50 percent grow more and 50 percent grow less. However, English language learners and students in special education tend to grow at a slower rate. Our data show that the median SGP for English language learners is about 45. The median SGP for students in special education is about 35 to 40. This means that when you review the test results for ELL students, you can consider an SGP of about 45 to be typical; when you review the test results for students in special education, you can consider an SGP of about 35 to 40 to be typical.