When our children are babies, pediatricians measure their height and weight at each checkup. Then they plot these vital statistics on a chart and keep track of them over time. That’s because a single measurement — a baby’s weight at say, her 3-month check-up — only tells us how big she is at that moment. For doctors to track whether a child is thriving, they need to understand how well she’s growing.

In much the same way, it’s hard to get a sense of how well a school is serving its students just by looking at standardized test scores in a given year. Each child carries a bank of knowledge and skills based on what they’ve been taught before, and students begin each year at different places academically. But no matter where a student starts, what’s important is what a school adds to each child’s learning. By measuring how much a school’s students learn over the course of a school year, we can get a much clearer picture of a school’s impact.

In an effort to track learning over time, researchers created a measurement called growth or student progress. Instead of just averaging a school’s end-of-year test scores, growth data tracks each individual child from year to year and measures how much progress they made. That metric is one of the primary criteria GreatSchools currently uses to calculate each school’s Summary Rating. (The other metrics are equity, test scores, and for high schools, college readiness metrics such as graduation rates and college enrollment.)

Depending on the data available in your state, GreatSchools measures growth in one of two ways. In states* that calculate student growth data, our Student Progress Rating averages all the progress that each student makes, compared to their peers at other schools in the state. In states* where individual student growth data isn’t available, we calculate an Academic Progress Rating. This rating uses school-level data that compares the performance of groups of students in consecutive grades across years. For example: comparing the performance of this year’s fifth graders to the performance of last year’s fourth graders.

3 key reasons why student growth matters

1. Test scores alone don’t tell the full story.

Research tells us that test scores are closely associated with a student’s socioeconomic background. Taken alone, these scores may not tell us much about how well the school is helping the student learn. Test scores also reflect a single point in time, typically when students take their state tests in the spring. Finally, test scores cover a limited set of subjects in certain grades–usually reading and math and sometimes science. Put simply: Test scores alone don’t necessarily reflect how effective a school really is.

2. Student growth shows how well schools are meeting students where they are.

Experts believe that progress is a more accurate measure of the ways a school contributes to student learning. Because students start each year with different levels of knowledge or skill, measuring growth can shine a light on how well the school is helping each of its students learn, whether they are ahead of or behind their peers.

3. Differences between test scores and progress ratings can provide useful insights.

Schools with high test scores can have low or high progress ratings, and schools with low test scores can have low or high progress ratings. A school with high test scores but low progress ratings raises certain questions: How much are the test scores due to the students’ background? Are the teaching practices strong? A school with low test scores but a high progress rating tells a different story. This school has students that are starting at a lower point academically, but compared to all schools in the state, they are learning more. This is a good sign: It takes highly effective teaching to help kids catch up to their peers.

Next steps for parents

When you’re choosing a school for your child, pay attention to the Student/Academic Progress Rating, and compare it to other schools near you (here’s how). Many states also use growth models to track school performance, so ask school leaders how they interpret these ratings.

Next steps for teachers

We know that growth ratings can be volatile at a classroom level, but taken together at a school level they may give you a snapshot of how your school’s students are progressing compared to other schools in the state. Whether you’re assessing how effective your school is or looking for a job, the Student/Academic Progress Rating is important to look at. A high growth rating should indicate that a school that has adopted effective teaching practices.

Next steps for school leaders

Whether your school or district has high or low test scores, your Student/Academic Progress Rating says a lot about the effectiveness of the practices at a given school. Consider sharing your scores with your community as a way of showing that your students are making progress toward success.

This is part of a series on our new 2020 ratings. Other stories include:

Why equity matters in school quality
No matter who your child is, how a school serves students from underserved communities is an important factor in understanding the school’s quality.

Why did my school’s rating go up?
You may have noticed that your school’s rating went up recently. There are two possible reasons for the change.

Why did my school’s rating go down?
You may have noticed that your school’s rating has dropped recently. There are two possible reasons for the change.

Read more about GreatSchools’ rating system.