Data sgp is an analysis tool for longitudinal student assessment data that creates statistical growth plots (SGPs) which display visual evidence of a students progress relative to academic peers. Using student standardized test scores with covariate information to establish an “expectation”, SGPs provide more accurate measurements of growth than traditional percentile score reports do.
By allowing educators to evaluate student progress and pinpoint areas for improvement within classrooms, data SGP helps educators target differentiation more effectively to meet the needs of all learners. SGP also allows for more accurate forecasting of the time required for a student to reach grade level, enabling more realistic achievement goals and targets.
SGP analyses are designed to be simple, straight forward and require minimal IT support. However, it is important that all steps of the SGP process are followed correctly and on-time – missing or delaying any preparation step could result in inaccurate or misleading analysis results. The bulk of the time in SGP analyses is spent on data preparation – it is estimated that 90% of the total analysis time is spent on this task.
Preparation of SGP data requires the creation of a relational database which stores the individual student assessment history and the associated scale scores. The database should be created on a platform with access to a server with sufficient computing resources for running large SQL queries. If the database is not configured correctly or the server has insufficient resources to handle the load, then SGP analyses will not run properly and may produce inaccurate results.
Educators can generate the SGP analysis report for a single student from the Star assessment summary report by selecting the “SGP Data” tab and choosing a student. The resulting spreadsheet will display the student’s SGP information for their most recent Star assessment and one prior test from a previous testing window.
The sgptData_LONG format data set provides an example of the WIDE format data that is used with the SGP functions. The first column, ID, provides a unique student identifier and the remaining 5 columns, SS_2013, SS_2014, SS_2015, SS_2016, and SS_2017, provide the student’s assessment scores for each of the five years they have been tested.
Creating SGP analysis with this data is straight forward, and the function documentation contains detailed instructions for its use. The sgptData_LONG data set is available for download at this link. Please refer to the SGP data analysis vignette for more comprehensive documentation on SGP functions and working with LONG format data sets in general. This is a good place to start for those who want to conduct SGP analyses with their own data. The vignette also includes an example of converting a LONG format data set into SGPdata format. SGPdata is a file format that has been specifically designed for this purpose. This file format is a good choice for data sets that will be used with SGP functions like studentGrowthPercentiles and studentGrowthProjections. It is not intended to replace the use of standard relational databases for other analyses such as aggregations and trend analysis.