Student Growth Percentiles (SGP) are a way of assessing students’ relative performance on MCAS subject-matter tests. They are produced by comparing the current score of a student to the scores of students with similar MCAS scaled score histories. The SGP score identifies whether the current score places the student above, below, or average among these academic peers.
Using SGP data, teachers can assess student progress and make informed instructional decisions. The SGP report provides growth information for each individual student, and also aggregates information at the school and district levels to examine trends in students’ performance. SGP data can be viewed in two ways: Window Specific SGP, whose purpose is to compare and report growth between specific time frames, and Current SGP, which simply shows the most recent SGP available for the student as a check-in on their progression.
For example, a student’s SGP in math is an indicator of how much the student has grown over their academic peers. If a student has a SGP of 75, it means that they scored higher than or equal to 75% of their academic peers with comparable score histories on previous MCAS test administrations.
It is important to remember that SGPs are not absolute measures of student achievement. For instance, a student’s SGP in science could be lower than or equal to 50 even if the student has shown outstanding growth over their academic peers. This is because SGPs are based on a comparison to academic peers that may not include all the students who have comparable MCAS scaled score histories in a particular classroom or grade.
When looking at aggregation of SGP data on an aggregate SGP graph, each bubble represents a single demographic group such as students who are classified as proficient or advanced. The size of each bubble varies according to the number of students in that group. When hovering the cursor over a bubble, the graph displays additional information about that group including mean SGP for that demographic.
Authorized users can drill down further to student details that provide multiple additional pieces of information for each student including the growth interval (e.g., sixth to seventh grade); each student’s growth percentile and corresponding growth level (high, low, or typical); scale score data and performance levels; and attendance rate in the school’s growth year.
The data sgp package contains the classes, functions and data needed to conduct SGP analyses. The lower level functions, studentGrowthPercentiles and studentGrowthProjections, require WIDE formatted data. The exemplar data set, sgpData_LONG and the teacher-student lookup file, sgpData_INSTRUCTOR_NUMBER serve as models for the format required by these functions. The SGPdata package also includes higher level functions, abcSGP and updateSGP, which “wrap” the below 6 steps into a single function call, simplifying the source code required for operational analyses.