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 using scores from a combination of Star tests taken during Fall, Winter and Spring testing windows (Fall–Winter SGP, Fall–Spring SGP, etc.). There are two types of SGPs: Window Specific SGPs (see the next section) that compare or report student growth for specific time frames, and Current SGPs that provide the most current SGP scores available for students (serving as a quick check-in for growth progression).
Current 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.
Student Growth Percentiles can be found in the following reports:
Window Specific SGP
Current SGPs are calculated based on the current date and tests available in prior test windows. In the Star Growth Report, Window Specific SGPs are calculated if you select a prior school year during the report customization (in the School Year drop-down list). In this report, you can also select which reporting periods are used: