How we rate

The GreatSchools Rating is a simple tool that helps you compare schools based on test scores and other available data, including student academic growth and college readiness. GreatSchools is always working to improve the rating and add more information when state education agencies make school quality data publicly available.

Ratings in your state
The GreatSchools Rating is on a 1-10 scale, where 10 is the highest and 1 is the lowest. Ratings are broken down into three categories: ratings 1-3 signal that the school is “below average,” 4-7 indicate “average,” and 8-10 are “above average.” Ratings for these categories are shown in red, yellow and green (respectively) to help you see the distinctions.

The foundation of the GreatSchools rating reflects how well students do on standardized tests compared to other students in the state, and ratings in most states are based exclusively on test scores. While test results give parents a good sense of how well students are performing at a given school, it only provides a limited snapshot of school quality. Therefore, in a growing number of states where data are available, the GreatSchools Rating includes additional information of student outcomes, such as information on how much students are learning in a given year and how prepared they are for college. The map below shows what data we include in the GreatSchools Rating by state — updated January 2017.

A broader picture of school quality

As states make more data on school quality available, GreatSchools is committed to providing this information to parents and incorporating it into the GreatSchools Rating. Based on extensive research on what contributes to long-term success for students, we are currently focused on three measures of academic quality:

Student achievement: Student achievement tells parents how well students at a school are doing in academics. This is measured as the percent of students meeting state standards based on state standardized tests. While this measure tells parents how well students at a school are doing currently, it does not necessarily show how much students are learning at that school — that is, how much students are growing.

Student growth: Measures of student growth tell parents how much students are actually learning in a year, rather than how much they already know. A school with high growth could be a school with students that started behind grade level and have now caught up. It could also be a school with students that started already above grade level and have moved even further ahead of similar students. Student growth is typically measured through gains on test scores year-over-year, comparing similar students with each other.

College readiness: Data on high school graduation rates and performance/participation on college entrance exams (such as the SAT and ACT) show how well students are prepared for life after high school in college or career.

Calculating ratings

In states with only data on test scores
In states where only student achievement is used to calculate ratings, the overall GreatSchools Rating is an average of how well students at a given school do on each grade and subject test. For each test, ratings are assigned based on how well students perform relative to all other students in the state, and these ratings are averaged into an overall rating of 1 to 10. The distribution of the GreatSchools Rating in a given state looks like a bell curve, with higher numbers of schools getting ratings in the “average” category, and fewer schools getting ratings in the “above average” or “below average” categories.

In states with data on multiple student outcomes
For states where ratings include student growth and college readiness information, the overall GreatSchools Rating is an average of how well students do on each sub-rating. Sub-ratings are weighted equally, though actual weights depend on the amount of data available per school and what grades that school serves. For instance, a K-5 school has no college readiness data, so the overall rating would be based 50% on student achievement and 50% on student growth. In contrast, the rating for a high school with data for all three measures would be based 33% on student achievement, 33% on student growth, and 33% on college readiness. Each sub-rating represents how a school compares to all other schools in the state on each measure, and these sub-ratings are averaged into an overall rating.

For more information on how GreatSchools calculates ratings, please see the GreatSchools Ratings Methodology Report.

Greater data transparency

At GreatSchools we believe that transparency builds trust. We believe that government education agencies have an obligation to make data on school quality available to parents and the public. Data transparency helps parents know how schools in their community are doing, where there is room for improvement, and what the best options are for their children. Of particular interest is information on student outcomes, such as student test scores, high school graduation rates, course completion rates, etc. Sharing school information — good and bad — also cultivates parent engagement and trust. Additionally, it’s important that school data be made available in accessible, easy to use formats so that non-governmental organizations can use the information to inform parents and students about the quality of their local schools.

For more information on GreatSchools’ commitment to working with government education agencies to provide better information on student outcomes, please contact us.