The data sgp package contains a set of lower level functions that do the calculations (studentGrowthPercentiles, studentGrowthProjections) and higher level wrappers (studentSGP) that do the aggregation. The package provides a number of exemplar WIDE formatted and LONG formatted data sets that can be used to model the creation of SGP analyses using these lower level functions. The sgpData vignette and SGPdata vignette provide more comprehensive documentation about how to use this data.

The sgpData and sgpData_LONG data sets contain longitudinal (time dependent) student assessment data for the state of MA. The data is provided in a panel format where each row represents a unique student and the columns represent the assessments at different times for the student. This is the same data format that is used by sgpstateData to create state-level SGP reports.

In general, SGP analyses require at least two assessment occurrences to calculate a students growth percentile. The two tests need not be from the same year but should have been administered within a few months of each other. It is important to have this consistency between the two tests for accurate comparisons of student growth.

To determine student growth, the SGP algorithm compares a students current assessment score to the scores of academic peers who have similar MCAS score histories. This is accomplished by establishing an academic peer group for each student from their previous MCAS administrations in the same subject area. The academic peer group includes all students who achieved a score that was equal to or better than a given score on the current assessment.

This allows for the identification of students who have demonstrated high, average or low growth on state assessments. Educators can then focus on helping these students improve their performance. Additionally, schools can review the aggregated results of their student groups to identify areas that may need improvement.

Students who have demonstrated strong growth can be encouraged to continue their progress, whereas students that are struggling should receive extra attention. In addition, educators can use student growth information to develop specific learning goals for each student.

Despite its limitations, SGP can be a valuable tool for teachers and schools. However, it is important to remember that SGP is a relative measure and should be interpreted in this context. For example, students who achieve the same MCAS scale score in a particular year can have very different SGPs because they have different academic peers. It is therefore not appropriate to make direct comparisons between students’ SGPs in different years. Only differences of 10 or more points should be considered significant.