Student Growth Percentile

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.

Student Growth Percentile is calculated for students who have taken at least two tests (a current test and a prior test) within at least two different testing windows (Fall, Winter, or Spring). The current test is the most recent test the student has taken in the most recent window that the student has tested in within the last 18 months. The prior test(s) are from the most recent SGP test window before the one that the current test falls in.

If a student has taken more than one test in a single test window, the SGP calculation is based off the following tests:

  • The current test is always the last test taken in a testing window.
  • The test used as the prior test depends on what testing window it falls in:
    • Fall window: The first test taken in the Fall window is used.
    • Winter window: The test taken closest to January 15 in the Winter window is used.
    • Spring window: The last test taken in the Spring window is used.
Type of SGP Score Test Scores Used
Fall to Spring Current Spring, Current Fall, and Previous Spring
Fall to Winter Current Winter, Current Fall, and Previous Spring
Winter to Spring Current Spring, Current Winter, and Current Fall
Spring to Fall Current Fall, Previous Spring, and Previous Winter
Spring to Spring Current Spring, Previous Spring, and the Spring before the Previous Spring
Fall to Fall Current Fall, Previous Fall, and the Fall before the Previous Fall

Note: If a student is held back a grade, SGPs will be calculated for that student using the previous school year's testing data. A held-back student needs to take two tests in two separate testing windows in the current school year before having an SGP calculated using the current school year's testing data.

Conditions in which an SGP cannot be calculated:

  • When no tests were taken in the past 18 months
  • When the only tests taken in the past 18 months are in the same window
  • When some of the Star Math assessments that would be used were taken before Grade 1
  • Spring to Winter
  • When the student's assigned grade is different during a school year for two different testing windows
  • When the data available was imported after the end of an SGP window (so no SGP is calculated for the next window)
  • When the grade associated with the Star Math test is greater than grade 12

Student Growth Percentile 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.

You will see the SGP on the fan graph for the student.

For more information about Student Growth Percentiles, refer to:

Student Growth Percentiles - Learn More