Last month, I had a consultation with a family preparing to move to Atlanta. They were debating between two homes. One was in a district with a GreatSchools score of 9, while the other had a score of 7. The price difference was nearly $50,000. "How good is a 9 score?" It wasn't easy to answer that question right away because I needed to explain how that score is derived, rather than just the score itself.

The GreatSchools score is not a number based solely on test scores. It is a value calculated from various factors, including test scores, college readiness, student growth, and equity, scaled from 1 to 10. For high schools, student achievement, student growth, and college readiness each account for about one-third of the score. For elementary and middle schools, an equity measure that considers performance gaps based on income or disability status is added. Thus, the number 9 includes not just test scores but also graduation rates and participation rates in advanced courses like AP or dual enrollment.

Even within the Atlanta Public Schools district, there is significant variation between schools. Mary Lin Elementary School has an overall score of 9.8, making it one of the top schools in the district, while Charles R. Drew Charter School, Bolton Academy, Burgess-Peterson Elementary, and Springdale Park Elementary also received scores of 9 (according to GreatSchools). The reason for such score differences within the same district is that school boundaries are drawn very specifically by neighborhood. It is not uncommon for the assigned school to change with just a street in between.

So, I explained to the family who asked about the difference between the scores of 9 and 7 that the 2-point difference is not an absolute superiority but rather a result of the combined test scores, growth, and equity. Additionally, I emphasized that the trend of the scores is just as important. Whether a school has consistently maintained a score in the 8 range for three years or suddenly jumped from a score of 5 last year affects its reliability. A sudden spike in scores could be due to changes in test participation rates or grading criteria, so it can be misleading to judge based on just one year's score.

The student-to-teacher ratio is also an important factor to consider. Even if the scores are the same, the actual educational environment can vary greatly depending on how many students are assigned to each class. Reading the reviews from parents and students on the GreatSchools page can also provide insights into the atmosphere that numbers alone cannot convey. Finally, the most crucial step is to verify the actual assigned school. School boundaries can change frequently due to district budgets or student enrollment adjustments, so if you find a home you like, be sure to check with the county education office to confirm the assigned school. The scores listed on real estate websites may differ from the assigned school at the time of your move.

When choosing a home, please check the following items as well:

• Recent 3-5 year trend of GreatSchools scores
• Student-to-teacher ratio and class sizes
• Recent dates and content of parent and student reviews
• Actual assigned school for the given address (check with the county education office)
• Graduation rates and college readiness indicators like AP and dual enrollment participation

In a city like Atlanta, where there is significant variation in school districts, a single score can lead to a price difference of nearly $50,000. Understanding the components of the score and approaching it thoughtfully can be practically helpful. This article is not investment or legal advice, and it is advisable to verify with a real estate professional and the relevant county education office before making any contracts.