Data SGP is an alternative way to measure student performance that provides a more accurate picture of a student’s current proficiency level and how much growth must occur to reach an achievement target/goal. It is a valuable tool for schools in states that set official proficiency targets/goals and require a certain timeframe to reach them. It also allows educators to effectively communicate how difficult it will be to reach these goals and helps them identify students who are at risk of not making progress towards them.
SGP measures a student’s rate of growth by comparing them to academically-similar peers based on their previous year’s test scores. For example, a student who is currently in sixth grade scored a scale score of 370 this year on the state assessment for English language arts (ELA). This year’s score indicates that they have made 70 scale score points more than their peer group. Those who have made more than the average of their peer group, or who are in the top 25% of their peer groups, have a higher SGP value.
In practice, multiple years of prior test scores are often used to generate SGPs. The current SGP values are based on the most recent assessment that a student took as well as the best available combination of prior assessments from their achievement history. In order to generate the most accurate possible SGPs, all available assessment results should be included in a student’s record.
Although SGPs are calculated using the same model, each school/district has the flexibility to choose which prior assessments will be used to determine their current SGP values. This means that SGPs can be compared across schools/districts to provide a more realistic picture of the current proficiency levels of their students. In addition, it allows administrators to more effectively track their student’s progress by ensuring that all relevant information is available in one place.
The bulk of the work associated with preparing and running SGP analyses is in the initial data preparation process. Once this is completed, the analyses themselves are simple and straightforward. Any errors that may arise when analyzing SGPs usually revert back to data preparation issues so it is important to focus on this first step in the process.
OSPI staff is available to offer training and support in all aspects of SGP preparation and analysis. This includes the use of the sgpData software, preparation of the data sets, and writing reports. We can also provide assistance with the development of new and more complicated SGP analyses for specific needs.
The sgpData software, available for download here, requires the use of LONG formatted data. The lower level functions that do the calculations, studentGrowthPercentiles and studentGrowthProjections, require WIDE formatted data whereas the higher level functions (wrappers for the lower level functions) are designed to be used with LONG data. In general, we recommend that all operational SGP analyses be conducted using LONG data in order to simplify the management of the data.