The data sgp package provides tools to analyze student growth data using R. As an open source software package that uses advanced functions, running SGP analyses requires familiarity with R. To get started, consult the SGP Data Analysis Vignette and the SGP Help Guide for an overview of the basic concepts and tasks involved in using data sgp.
The SGP package is designed to support teachers and administrators by enabling them to use student growth percentiles to identify students who may be struggling or are not growing as much as expected. Student growth percentiles are calculated by comparing a student’s assessment score path to that of a group of academic peers, defined as all students in Washington State who have valid and consecutive test scores in the same grade and subject, and who have statistically similar histories on the same assessment.
Data SGP also provides a number of other educational metrics for analyzing student performance. These include a range of trend metrics that highlight the direction (positive or negative) of a student’s assessment score path over time, and a set of projections that allow users to predict future scores given current performance.
To run SGP analyses, a computer with the free version of R installed is required. The software is available for Windows, OSX, and Linux and can be downloaded from the CRAN website. Once the software is installed, a copy of the sgpdata package must be downloaded and a new instance of the SGP state data file created.
sgpData is an anonymized panel data set that includes 5 years of annual, vertically scaled, assessment data. It is provided in both WIDE and LONG format. The lower level functions that do the actual SGP calculations, studentGrowthPercentiles and studentGrowthProjections, require WIDE formatted data whereas the higher level functions (wrappers for these) are designed to be used with LONG formatted data sets.
Assuming the sgpData file has been set up correctly, SGP analyses are fairly straightforward. Any errors that are encountered often revert back to issues with the data preparation process.
The sgpData_INSTRUCTOR_NUMBER table is an embedded table that provides the teacher number associated with each of a student’s test records. The sgpData_INSTRUCTOR_NUMBER row in the sgpData file contains the same information that is entered in the sgpData_TEACHER field on the sgpStateData form.
The SGP state data files contain information on all Star assessments administered for a student over their entire lifetime. They are used by SGP to calculate and report student growth percentiles and projections, and for other educational purposes. These files are made available to school districts and teachers through the sgpStateData Web application. The sgpstateData Web application is the official source of Washington state SGP data and does not make use of any externally generated files or other databases. As such, it is an ideal tool for creating and maintaining SGP data sets. This is the most up to date data set for calculating SGPs and projections for all students in Washington.