MCAS Student Growth Percentiles
Student Growth Percentiles (SGP) compare a student’s current test score to that of students with similar prior scores (their academic peers). The model is designed to give teachers and administrators more meaningful information about a student’s progress toward meeting state standards. SGPs are calculated using up to two years of historical MCAS assessment data for each subject area, and are available in both Window Specific SGPs, which compare a student’s performance over a single time period, and Current SGPs, which provide the latest SGP available for a student.
Students may also have their SGP reported as a percentage, which is an indication of the relative strength of their performance in comparison to other students across all subjects and grades. Percentiles are useful in that they provide an easy-to-understand metric that allows for the comparison of a range of student achievement levels.
What are the requirements for students to receive a SGP?
Students must have valid, consecutive test scores in order for their SGP to be calculated. SGPs are not available for students who enter school in the same grade and subject as they exit, nor are they available for science or writing assessments.
The SGPdata package provides 4 examplar data sets for use with SGP analyses. The first, sgpData, specifies data in the WIDE format that’s used with the lower level SGP functions studentGrowthPercentiles and studentGrowthProjections. The second and third data sets, sgptData_LONG and sgptData_INSTRUCTOR_NUMBER, specify data in the LONG format used by higher level SGP functions like abcSGP, prepareSGP, and analyzeSGP. The last, sgpData_INSTRUCTOR_NUMBER, is an anonymized teacher-student lookup table utilized to produce teacher level aggregates.
Can two students with the same MCAS scaled score history have different SGPs?
Yes. The SGP calculation compares a student’s current MCAS score to that of academic peers with similar MCAS scores from previous years. Student B’s MCAS scaled score history is closer to the majority of academic peers than student C’s, so they have a higher SGP than Student C.
It’s important to remember that SGPs are based on trends in statewide performance, which means that it’s possible that one year a large number of students could show more or less growth than the previous year. For example, the Covid-19 pandemic caused a dip in student performance nationally that shifted SGPs for all students. SGPs are updated each year to reflect this shift in student performance. In the future, this shift will be reflected in new SGP calculations that are based on more recent MCAS test scores. In these calculations, student growth in the lowest performing subgroups will likely decrease slightly while the highest scoring students experience a slight increase in their SGPs. This will allow for more accurate reporting of the percentage of students growing at or above the state average. Ultimately, the goal of the SGP model is to ensure that all students are progressing at or above the state average rate. This is a key component of the Governor’s plan to prepare all students for success in college, career and life.