How to Calculate Student Growth Percentiles With Data SGP
Student Growth Percentiles (SGP) are a new and improved way to compare a students performance to that of their academic peers across the state. SGP is based on the historical growth trajectories of previous MCAS scores and determines relative performance compared to other students. The SGP model uses a quantile regression method to calculate a students growth percentiles. The technical resources on the Washington SGP Technical Resources page describe how SGP is calculated.
The data sgp package provides the necessary input data and analysis functions for calculating a students SGP. The lower level SGP functions studentGrowthPercentiles and studentGrowthProjections require WIDE formatted data while the higher level sgpData functions (wrappers for these lower level functions) use LONG data. In general, using SGP with data sgp is straightforward following proper data preparation. If you run into problems, in almost all cases the issue relates to the data.
sgpData contains an anonymized panel data set in long format that consists of 8 windows (3 windows annually) of assessment data for 3 content areas. This data includes a student’s unique ID, identifiers for the teacher and classroom associated with each test record, the teachers’ name, and the student’s score in each of the assessments. The data set also contains an additional field for “INSTRUCTOR_NUMBER”. The sgpData_INSTRUCTOR_NUMBER field provides a lookup table that associates each test record with the teacher that taught the student.
In order to calculate a students SGP, the program needs two recent assessments for each student. The first assessment must be from a previous window and the second assessment must be from the current window. The most recent assessment is used to calculate a student’s current SGP and the previous window SGP is used to project a future score that would be needed to reach or maintain proficiency on future MCAS tests.
This future score is compared to the SGP of the student’s academic peer group to determine the growth percentage required for the student to reach their target. The goal is to identify a student’s projected score that will put them at the 95th percentile of their peer group in the current year.
The SGP vignettes are a useful tool to help explain how the student growth percentiles are calculated and what information is available to support a district or school in improving their instructional practice. They are available in PDF and HTML format. The vignettes provide an overview of the student growth percentile calculations, a description of the available resources for interpreting and analyzing the data, and detailed instructions on how to access and analyze the SGP data. The vignettes are designed to help users understand and utilize the new SGP tools in the Star website. If you have an idea for a vignette topic, please share your ideas by commenting on this article or by setting up an issue on Github. We look forward to hearing from you! Thanks for reading. Good luck! We wish you all the best on your educational journey.