Data SGP is an analysis tool for the statistical software environment R. It allows educators and researchers to use longitudinal student assessment data to better understand their students’ progress. The tool is designed to help teachers and schools identify areas of growth, as well as to target areas for improvement. It also supports teachers in their efforts to develop and implement meaningful Student Learning Objectives (SLOs). The SGP approach differs from other measures of academic growth by allowing schools to set proficiency targets over time, rather than only measuring performance in one test period.
To run the SGP script, a computer running Windows or OSX and access to the open source version of R is required. Users can download the software from GitHub or can use the online, guided vignette to perform the analysis. The vignette provides guidance on navigating the user interface and interpreting the results.
The SGP script can be used with either WIDE or sgpData_LONG formatted data sets. Both data sets contain student information in a wide format, with each case/row representing one student and columns representing variables associated with the student at different points in time. In addition to the student data, the sgpData_LONG data set contains the variable sgpData_INSTRUCTOR_NUMBER, an anonymized lookup table that associates a teacher with each test record in the wide format.
For each student in a given year, the SGP tool calculates an individual growth percentile, or SGP. The SGP is a measure of student performance that indicates how much a student has grown relative to students with similar prior achievement histories. The lower the percentile, the worse a student’s growth. The higher the percentile, the more a student’s growth has been above average.
Each student’s SGP is compared to the growth of other students in the same grade level, with a teacher’s overall mean growth percentile calculated as the sum of all of their students’ SGPs divided by the total number of scores. Teachers with the lowest mean growth percentiles are those whose students have demonstrated the least amount of academic growth.
Those with the highest mean growth percentageiles are the most effective teachers, as their students have made the most progress on their road to proficiency. Educators can then look at the average growth of all of their students to determine how to best focus their improvement efforts. The SGP is a powerful new tool that gives teachers and administrators the insight they need to make meaningful improvements in their schools.