DATA SGP is an analysis tool that allows users to visualize the growth of student assessment scores over time using longitudinal data. SGP can be used to help educators understand the progress of students and identify opportunities for improving instruction or accelerating learning. Unlike VAMs, which only reveal the relative ranking of students, SGP provides insight into how much a student is growing compared to academically-similar peers.
SGPs are calculated based on a statistical model of how students perform on standardized tests, taking into account factors like prior performance and classroom composition. Unlike traditional percentiles, which use fixed scales, SGPs are a measure of how much a student is growing compared with their academic peers – higher percentages indicate more growth than lower ones.
A SGP can range from 1 to 99 and is interpreted just like a percentile rank, for example, a student with a SGP of 50 means that they are growing at the same rate as half of all students with similar score histories on a subject-matter test. Students who demonstrate very different levels of achievement can have the same SGP because the metric is based on a mathematical formula that takes into consideration a student’s current level of achievement as well as their previous score history.
Educators can utilize SGP results for a variety of purposes including informing instructional practice, supporting classroom research, and evaluating students/teachers/schools/districts. However, while they provide valuable information, it is important to remember that SGPs only show a student’s growth and does not determine whether stakeholders would consider the growth level adequate or that a teacher’s classroom composition has been effective.
Getting started with SGP analyses can be challenging as the majority of time needed to perform an SGP is spent on data preparation and formatting – both of which require experience with the open-source programming language R. For this reason, we strongly recommend that those wishing to utilize data sgp familiarize themselves with the SGP Data Analysis Vignette, which provides detailed instructions on setting up and running SGP calculations.
The sgpData package includes exemplar WIDE format (sgpData) and LONG format (sgpData_LONG) data sets to assist with the conversion process to SGPdata, and the lower level functions like studentGrowthPercentiles and studentGrowthProjections work best with the wide format. The sgpData_LONG format is ideal for those who plan on performing SGP analyses operationally year after year since the LONG data set has many benefits over WIDE data when it comes to preparation and storage.
To convert a WIDE data set into the SGPdata format, simply open the sgpData file in an editor such as Excel or Google Sheets and select the option to “Save As” a copy of the file in a new, blank file. Then, follow the instructions in the sgpData vignette to import the new file into one of the SGP tools available on this site. For more assistance on the process please visit this data sgp tutorial video or our Frequently Asked Questions page.