What are student growth percentiles?
A student growth percentile (SGP) describes a student's growth compared to other students with the same initial test score. SGP is similar to a standard percentile, but instead of measuring student achievement compared to peers, SGP measures comparative growth. The student growth percentile allows us to compare the growth of students at different achievement levels.
Like all percentiles, SGP is a number between 1 and 99. Receiving an SGP score of 70 indicates that you demonstrated more growth than 70 percent of your academic peers. A student with a low raw score can show high growth, and a student with a high raw score can demonstrate low growth. Similarly, two students with very different test scores can have the same SGP.
SGP is commonly used at the school, district, and state level as the primary growth metric or a key performance indicator. Traditionally, SGP is used to calculate growth year-over-year on a given exam. However, here at Test Innovators, we take advantage of our large pool of historical data to calculate SGP test-to-test on much smaller time scales.
How are student growth percentiles calculated?
Student growth percentiles are measured by calculating the raw score change between test sections of the same subject (e.g. Reading) for a given student. This difference is compared to the distribution of score changes for past students with initial section scores similar to that of the student of interest. By observing where the student’s score change falls on the distribution, we can estimate the student growth percentile based on the expected growth for the student’s initial achievement level (scores on the initial test section).
To whom are students being compared? What is an academic peer?
When calculating the SGP, students are compared to their peers with a similar achievement level on the previous exam. Peers include all Test Innovators students who completed that particular test section in the past. Raw section scores are the only factor Test Innovators takes into account when comparing peers.
Can high-scoring students still demonstrate growth?
Yes. Students with high raw scores on previous test sections will be compared to all other students who also achieved high scores in the past. Even high-performing students have varied performance; for this reason, students with high test scores may notice that simply maintaining their high achievement is indicative of growth, given the relativity of the SGP metric.
Which students receive growth percentiles?
All students (excepting those with trial accounts) will receive student growth percentiles. However, due to the nature of SGPs, students must complete at least two of the same test section in order to receive an SGP score.
What can student growth percentiles tell us?
Student growth percentiles are a descriptive metric, like test percentiles, and describe the amount of growth a student has made since the previous test. SGPs can help answer questions like the following:
- For individual students:
- Is the student growing at an appropriate rate?
- Is the student demonstrating more growth in some test sections than in others?
- For classes or groups of students:
- Are there students with low growth who may need additional support?
How will the student growth percentile data be used?
SGPs is used alongside student performance metrics to identify student needs and to further personalize our platform to meet student needs. Students can access their SGP data from the Analysis tab of their accounts by scrolling down to the “Your Growth” graph, which can be toggled to display different metrics, including SGP.