Student growth percentiles are a method of quantifying student progress by comparing their current assessment scores to students with similar prior test scores (their academic peers). The calculations behind SGPs can be complex, but the results are communicated in terms that most teachers and parents will find familiar. SGPs are used by states across the country to inform teaching and learning practices, provide evidence of student achievement, and help identify student groups that need extra support.
Data SGP is a set of functions that work with longitudinal, time dependent, student assessment data in WIDE format or LONG format. These higher level functions can be used to produce studentGrowthPlots or growthAchievementPlots that visualize a variety of data points at various points in the progression of student assessment data.
A key feature of the sgpData set is the sgpData_INSTRUCTOR_NUMBER table. This is an anonymized lookup table providing instructor details associated with each student test record in a content area for a given year. It is possible for students to be taught by multiple instructors within a single content area during a given year, so this information helps educators understand how their instructors contribute to each student’s success and understanding of the curriculum.
The sgpData functions use the data in sgpData to construct studentGrowthPlots that can be displayed on a web browser or in PDF form. The output can be tailored to a specific display or printing style by adjusting the parameters of sgpPlotTemplate. In addition, the sgpPlot template can be modified to display only particular subsets of a student’s data or data from one particular point in time.
In addition to student growth percentiles, the sgpData functions can produce other types of educational visualizations such as achievement level cuts and student performance graphs. These charts can be customized to include only the data a teacher wishes to see or to display all of the available student growth and achievement data in a chart.
These charts and graphs can also be customized to include a title or background image as well as a label for the chart. Finally, sgpPlots can be configured to display a range of additional information about the selected data including a student’s name, grade level, subject, and academic peers.
In order to configure sgpPlots to use your desired data and display settings you will need to adjust the sgpPlotTemplate that you create using the sgpPlotCreator function. In addition to the template configuration options there are several additional arguments that can be passed into the sgpPlotCreator such as a Boolean argument indicating whether or not studentGrowthPlots should be produced, and if so, for which students. The sgpPlotCreator also accepts an integer parameter which determines the number of years to display for a pdf student growth plot and an optional parameter which specifies the maximum coefficient matrix order to utilize when building a studentGrowthPlot. This is important because different order values can impact the slope of the trajectories shown in the plots.