Student growth percentiles (SGP) are a statistic that indicates how much a student grew in an academic skill from one year to the next compared to their “academic peers.” They provide a way for teachers and administrators to see if students grew more than, similar to, or less than their peers. SGPs are meant to be considered along with scaled scores and achievement levels to gain a more complete picture of student learning.
A student’s SGP score is reported as a number between 1 and 99. The higher the SGP number, the greater the relative growth. SGPs are calculated based on a statistical method called quantile regression. Quantile regression is a statistical technique that places the performance of a group of people on a normative scale so that their individual performances can be compared to one another.
The SGP calculation uses up to two years of MCAS data to identify the academic peers of a student. Academic peers are defined as students in the same grade and assessment subject who have had comparable previous MCAS performance. Academic peers are not identified based on any demographics, special needs or educational programs that the student may be enrolled in. This is to ensure that all students are being compared on their abilities, not their demographics or other characteristics that could influence performance on the MCAS tests.
There are two types of SGPs that can be generated: Window Specific SGP and Current SGP. Both can be found in the Star Growth Report. Window Specific SGPs are calculated when a school or district selects a prior or current school year for their SGP report customization in the Timeframe drop-down list. Current SGPs are generated for every student who has taken at least one test in a single testing window (Fall, Winter or Spring).
The higher the SGP score, the more a student has grown from their previous assessment scores. However, it is important to keep in mind that a small percentage of students have zero or negative growth. The statewide median SGP is 50.
In addition to the resources on this page, you can also find more information about SGPs by visiting the Student Growth District and School Resources webpage. In addition to information on the SGP model and technical documents, the website contains videos that can be used for training purposes in schools and districts.
OSPI has received many questions from educators around preparing data for SGP analyses and understanding the results. We have worked to keep the process of running SGP calculations as simple as possible. Most errors that are encountered when conducting SGP analyses can be traced back to the preparation of the data. If you are experiencing difficulties with your SGP analyses, please contact your regional support center for assistance. Thank you for your continued efforts to support student learning in Washington state. We look forward to continuing to work with you in 2023 and beyond!