Student Growth Percentiles (SGP) compare a student’s current assessment score to that of students with similar previous test scores. It allows us to fairly compare students who enter school at different levels and helps us identify whether a student is falling behind.
SGP analyses are complex and time consuming. The bulk of the analysis is spent preparing data for analysis, and many errors encountered during SGP analyses are due to incorrect or incomplete preparation of the data. While the ARM training team has been available to assist districts and schools in preparation of SGP data, it is at the discretion of individual districts/schools to decide how much time and energy to dedicate to SGP calculations and reports.
The SGP package offers higher level functions (wrappers for the lower level studentGrowthPercentiles and studentGrowthProjections) that simplify the SGP analysis process. The lower level functions are primarily dependent upon WIDE formatted data. In addition to the higher level function wrappers, the exemplar longitudinal data set sgptData_LONG and an anonymized teacher-student lookup file sgpData_INSTRUCTOR_NUMBER can be used to assist with SGP data preparation.
To run SGP analyses, you will need two or more sets of statewide student assessment data. The first data set needs to contain a recent test, and the second data set must have at least one prior test from an earlier testing window. The tests in a prior testing window need not correspond to a particular school year. In addition to these two data sets, you will also need a list of teachers and students for each content area.
Using the higher level SGP functions, you can determine students’ current SGPs and student growth projections by applying regression models to the data set. The model results are then displayed for each student in the form of a line graph showing the current SGP at each point in time. You can also calculate goodness of fit figures for each student, which are then saved as PDF files into a directory labeled Goodness of Fit.
For each student, you will also want to see the current and tenth percentiles of their state-specific SGP as well as their cumulative growth rate (CGR). You can access these values by creating a tabular report of students. To create this table, select the Student Growth tab, and then click on the “View/Add columns” button in the upper right corner of the table. This will open a dialog box where you can specify the columns that you would like to see in the final report. Click “OK”. The final report will be created and automatically updated each time the higher level SGP functions are run. The final report is a useful tool for interpreting the SGP results and planning student-level interventions. This data is provided free of charge through the ARM Data Discovery website.