Student Growth Percentiles (SGP) are an important component of a comprehensive understanding of student performance. SGPs provide data about how students are progressing toward proficiency and are a valuable tool for educators, administrators, and parents. As such, it is important that all stakeholders have access to accurate and understandable SGP data.
To ensure that SGP data is as accurate and understandable as possible, OSPI provides a variety of tools and training materials to help districts and schools make the most of the data. The SGP Data Guide, the student growth percentiles calculator, and the SGP Technical Resources webpage are all good places to start.
While SGPs are useful, they are a complex measure and interpreting them requires some knowledge of statistics. For this reason, it is recommended that districts and schools invest time in training prior to high stakes use of SGP data.
SGPs are a measure of relative performance, meaning they compare a student’s current assessment score to the scores of their academic peers with similar MCAS score histories from previous test administrations. As such, it is not unusual for two students to have different SGPs, even if they have the same scaled score history.
A student’s SGP is a rank order of their percentile change on a scale from 1 (lowest growth) to 99 (highest growth). For example, Simon has a score of 72 and an SGP of 63, meaning his current score puts him in the 62nd percentile for the MCAS exam in that content area.
SGP data is updated regularly, and the SGPs that appear on a Star Growth Report are based on the most recent information available. In addition, you can select a specific window of time in which to view a student’s SGP when customizing a report by using the Timeframe drop-down list.
The SGPdata package contains 4 examplar data sets that can be used for conducting a range of SGP analyses. The data set sgpData_LONG specifies the WIDE format required by lower level SGP functions such as studentGrowthPercentiles and studentGrowthProjections, while the data sets sgptData_LONG and sgpData_INSTRUCTOR_NUMBER specify the LONG format required by higher level functions such as abcSGP, prepareSGP, and analyzeSGP.
The sgptData_LONG data set also includes the student level aggregates generated by prepareSGP and analyzeSGP. In general, these aggregates will contain all of the information you need to understand a student’s performance, including their SGP and performance level. This is useful for creating reports to share with teachers and parents. The sgptData_INSTRUCTOR_NUMBER data set includes the teacher-student lookup files needed to produce these aggregates.