Data SGP is a software package for analyzing large scale longitudinal education assessment data. It provides tools for calculating student growth percentiles and percentile growth projections/trajectories using quantitative regression, which calculates the conditional density associated with each student’s achievement history.
SGP analyses require the use of a statistical program called R, which is free and can be downloaded for Windows, Mac OSX or Linux. The bulk of the work in preparing SGP data is done through the prepareSGP function, which takes the user’s long formatted data and creates additional variables that are often used in SGP analyses such as HIGH_NEED_STATUS identifying students in the top or bottom quartile and CONTENT_AREA_PERCENTILE indicating which content areas have low or high needs for each year.
The SGP package also contains functions to convert between WIDE and LONG formatted data and to handle duplicate records, which are a common problem with longitudinal data sets. It can also be used to generate reports displaying results of the SGP analyses.
Teachers seeking SGP data can access it through their state’s website, which usually offers a list of individual student scores by subject area and grade level along with information about the percentage of students who fell outside of the curve for each subject tested. This helps educators determine which students need more attention and which may be eligible for academic intervention programs.
As with all analyses, a large portion of time is spent in the preparation phase, and any errors that occur while running SGP calculations usually revert back to problems with data preparation. However, once the data is prepared correctly, analysis is designed to be fast and straightforward.
A new feature in the SGP package allows it to be used with a graphical user interface (GUI) that makes it easier for users of all skill levels to use. The GUI, called R Studio, provides a point-and-click interface that eliminates the need for manual programming and makes it easy to set up a database, create scripts for importing and exporting data, run SGP calculations and view results.
The GUI also simplifies the process of loading data into an existing database and allows for more complex transformations than can be done through the raw R code. In addition, it includes tools to help users develop more complex scripts that can be used in batch mode. The GUI can be downloaded for free from the RStudio website. This tool can be used to analyze data from a wide range of sources. It is also useful in preparing data for the SGP model. It is important to note that the software must be installed on the same machine as R in order for the GUI to be available. The SGP team is working to make the GUI available for other platforms in the future. This will allow more people to access and use the SGP software. It will also help reduce the amount of time required to install and learn the R programming language.