Student Growth Percentiles (SGP) measure a students performance in relation to other students across the state. SGP scores are used by educators to determine the strength of their instructional programs and identify areas for improvement. While traditional assessment reports indicate a student’s achievement level, SGP reports provide more detail by showing how a student has progressed from one year to the next.
A typical SGP report shows a list of student assessment results for each subject area. It also displays a student’s SGP score, which is calculated by comparing the student’s current assessment score to his or her previous assessment score. The score indicates a student’s overall level of achievement, with the higher the number the better. The report may also display a trend line graph that plots the student’s SGP score over time.
There are several resources available to help teachers understand how to interpret their SGP results and find ways to improve student learning. A good place to start is the SGP data help page on the MCAS website. The page contains links to detailed explanations of the calculation and interpretation of SGP scores, as well as examples of student growth patterns.
In addition, the sgpdata package provides tools to support the calculation of student growth percentiles and percentile growth projections/trajectories. These are calculated using large scale, longitudinal education assessment data using a quantile regression model. The sgpdata package includes functions to extract the necessary coefficient matrices for this type of modeling as well as methods to visualize these projections/trajectories.
The sgpData_INSTRUCTOR_NUMBER lookup table provides instructors associated with each student’s test record. This is an essential component of the data needed to calculate Student Growth Percentiles and percentile growth projections/trajectories, as it allows SGPs to be compared to the growth rates expected from a particular teacher’s class.
While SGPs are useful for analyzing individual student progress, they can also be used to analyze school and district-level performance. A statewide median SGP will always be approximately 50 because the norms for the current year are typically established using student scores from only that grade. However, average SGPs for schools, districts, and subgroups can fluctuate from 50 because they are based on smaller sample sizes of the available data.
If you have ideas for future SGP vignettes or would like to see a specific topic covered, please contact us via the sgpdata GitHub repository. We are always looking for ways to make SGPdata more user friendly and helpful. Your input is important!