Data sgp is an R software package that provides classes and functions for calculating student growth percentiles and projections/trajectories using large scale, longitudinal education assessment data. These percentiles and projections are calculated by applying a process called quantile regression to the assessment data. The output from this analysis is an estimated conditional density matrix for each student, which is used to calculate the students’ projected growth trajectories. These trajectories are then displayed in the Star Growth Report.
In order to run the SGP analyses you will need a computer with the R software installed. R is available for Windows, OSX and Linux and is free of charge. You will also need to have access to the Star Assessment data that you would like to analyze. To obtain this data you can use the NJSMART website to download a full export of data which includes principal and AP/VP, teacher and student information.
You can then open the file containing the data that you want to use in the SGP package by selecting the option “Open in the SGP package” in the File menu or clicking “Open SGP Data”. Once the data has opened you can then select a prior or current year for your report. The resulting report will display your student’s growth trajectories for both the selected years.
The sgpData data set is an anonymized, panel data set that contains 5 years of annual, vertically scaled, assessment data in WIDE format. This exemplar data set models the format of the data used by the lower level studentGrowthPercentiles and studentGrowthProjections functions. The first column in sgpData, ID, provides the unique student identifier. The next 5 columns, GRADE_2013, GRADE_2014, GRADE_2015, and GRADE_2016 provide the grade level associated with each of the student’s assessment occurrences. The final 5 columns, SS_2013, SS_2014, SS_2015, and SS_2016, provide the scale scores for each of the student’s assessment occurrences.
While using sgpData with the SGP package is simple, formatting your own data in WIDE format can be somewhat confusing for new users. It is recommended that you consult the SGP Data Analysis Vignette for more detailed explanations of how to work with sgpData (and WIDE data formats in general) for SGP analyses. You may also wish to contact the developers of SGP for further questions about the usage of sgpData and the SGP package. If you are new to R, it is recommended that you spend some time familiarizing yourself with the software before running any SGP analyses. This is especially important if you plan on utilizing SGP in an operational fashion, running analyses on a regular basis over multiple years. The more familiar you are with the software, the easier it will be to use and maintain in the future. This will ensure that your analyses continue to be accurate and reliable. It will also allow you to develop your own reusable scripts for running SGP analyses. This will be particularly helpful if you are responsible for implementing and maintaining the SGP package in your organization.