Students’ growth reports provide a unique and valuable perspective on their performance on MCAS tests. Growth percentiles show how much a student grew in comparison to other students with similar test score histories, and they can be used as a more meaningful measure of progress than traditional assessment scores. To help educators and parents understand the meaning of a growth report, DESE has produced two new guides. One guide is for administrators and the other is for teachers. Both of these guides describe the growth reports and offer prompts for using them in classroom discussions and reflections. These guides are available on the MCAS Growth web page.
A student’s growth percentile (SGP) is a number on a scale of 1-99 that indicates how much a student grew in comparison with his or her academic peers. For example, a student’s SGP of 75 means that the student grew about as fast as the bottom half of his or her academic peers. A SGP of 99 indicates that the student grew about as fast as all other students.
To determine a student’s SGP, we compare the student’s current score to the average SGP of students with similar scores on previous MCAS assessments. This process, known as normative growth modeling, provides an estimate of a student’s relative performance to his or her academic peers. In most cases, a student’s SGP is an accurate reflection of his or her progress. The exception is for students with very high scores, who are likely to have a SGP close to 99 and may not be accurately represented in the normative growth model.
Statewide median SGPs are almost always 50 since the SGP scale is normative and the median represents the point at which half of all students grew below or above the average SGP. Some individual schools, districts, and subgroups have SGPs that differ from the statewide median due to slight misfit, the assignment of students with the highest possible scaled score—Highest Obtainable Scale Score (HOSS)—to an SGP of 99, or the use of different base methods for calculating the SGP percentiles.
The data sgp tool provides information about a student’s growth based on his or her past performance on MCAS and SAT tests. The data sgp tool allows users to select a window specific SGP or a current SGP, as well as an average SGP for the school/district/subgroup.
To run data sgp analyses, you will need to install the R software package on your computer. The lower level functions that do the calculations—studentGrowthPercentiles and studentGrowthProjections—require WIDE formatted data while the higher level wrappers for these functions require LONG formatted data. The simplest analyses can be run with either format, but we recommend that you use LONG data whenever possible to take advantage of the full capability of the tool. Any errors encountered in running the tool will usually revert back to data preparation issues. If you are unable to resolve the error, contact the data sgp team.