Student Growth Percentiles (SGPs) are statistics used to measure how much academic skills have improved relative to “academic peers.” SGPs range from 1-100; generally speaking, the higher their number is, the more significantly a student has improved relative to peers.
SGPs are intended to complement scaled scores and achievement levels as part of an all-inclusive picture of student learning. When making decisions regarding instruction, SGPs should be considered alongside both factors.
SGPs are determined by comparing a student’s performance on the Star Assessment with that of academic peers nationwide who share similar achievement histories on prior year MCAS tests. This process, known as normative growth analysis, uses statistical techniques like quantile regression to plot performances against a standard normal distribution and determine their SGPs.
The data sgp package offers four example data sets suitable for SGP analyses. SgpData provides data in WIDE format that’s necessary for studentGrowthPercentiles and studentGrowthProjections functions; two additional datasets — sgptData_LONG and sgptData_INSTRUCTOR_NUMBER — supply LONG format required by functions like abcSGP, prepareSGP and analyzeSGP.
All of the functions discussed above require at least 7 variables, as each analysis utilizes multiple SGP models over different time periods – including standard normal models, ICCDF models and more specialized ones such as predictive growth simulation models – in their calculations of SGPs and anticipated student growth trajectory.
Once a student’s SGP has been determined, the next step should be comparing that score against those from his or her school district or across the state. With Star Reports’ customizable features such as SGP comparison windows or windowed reports, this comparison can easily take place.
Comparison windows display SGPs that can then be used for various purposes such as educator evaluation and instructional improvement. For more information about how to interpret growth reports in relation to educator evaluation, consult one of these stakeholder guides:
Note: Accurate district course roster submissions are key for reliable mSGP results. The New Jersey Department of Education offers several resources that can assist districts with this process, such as a video that walks users through the submission process and guides written specifically for administrators, educators and families on reading and interpreting statewide growth reports. Furthermore, there are tools available at their mSGP Resource Center that enable educators and families to translate mSGP scores into teacher evaluation ratings; such as growth conversion charts and lists of approved evaluation measures – both can help districts in this regard.
