The data sgp package provides classes, functions and data to support SGP analyses. While SGP analysis can be conducted using the lower level functions studentGrowthPercentiles and studentGrowthProjections, it is recommended that one use the higher level wrapper functions prepareSGP and updateSGP for operational analyses. These higher level functions simplify the source code associated with these analyses. In addition, they take advantage of the LONG format which provides many benefits over working with WIDE data.

Students statewide who participate in MCAS testing each year are provided with a score called a Student Growth Percentile (SGP). The SGP is based on a comparison of a student’s MCAS performance to that of their academic peers across the state, excluding demographic groups and educational programs such as sheltered English immersion and special education.

SGPs are intended to be used along with scaled scores and achievement levels as part of a full picture of student learning. They are a measure of a student’s progress relative to their academic peers, and can be reported as whether the student is above or below the average for their grade level, or at or above the average for their subject area.

SGP scores are calculated by comparing a student’s current MCAS performance to that of their academic peers statewide who scored similarly on at least two prior MCAS tests. This calculation is performed by using a statistical technique called quantile regression. The results are then placed on a normative scale allowing the identification of a student’s percentile rank in a given subject area.

Since SGPs are a measure of relative performance, their ranking may change from year to year. It is important to remember that a difference of less than 10 points between SGPs from different years should be interpreted with caution.

Each summer the Department of Elementary and Secondary Education (DESE) releases a variety of reports to stakeholders that include mSGPs. These reports are intended to inform parents, educators, and administrators about student progress over time and are designed to help them interpret the growth reports their schools receive. These reports are available on the MCAS growth webpage.

During the summer following each year’s statewide assessment, districts submit and certify course roster submission data through NJ SMART. These submissions list the students assigned to each teacher, and are linked to their mSGP scores by the DESE. This information is used to calculate a teacher’s final evaluation rating. For more information on how mSGPs are used in educator evaluation, see this article.