Last week during a consultation, I received this question. While looking for a home in Lexington, someone asked if a school score of 10 on a real estate site really means it's a 10-point school. The answer is not that simple.

Lexington is known for its school district even within Massachusetts. Bridge Elementary School and Maria Hastings Elementary School received a GreatSchools rating of 10. Harrington Elementary School has a score of 9. Just looking at the numbers, it seems there isn't much difference between the schools.

The problem arises when people view these scores without understanding how they are calculated. GreatSchools scores are not based solely on test scores. They combine several factors, including Test Score Rating, which looks at how students performed on tests, Student Progress Rating, which assesses how much students have grown as they advance through grades, and College Readiness Rating, which evaluates how prepared high school students are for college.

College Readiness Rating considers college entrance exam scores, high school graduation rates, and the completion rates of advanced courses like AP or IB. While this does not apply at the elementary level, it's important to check the middle and high schools your child will be assigned to as they grow. Sometimes, families make decisions based only on elementary school scores and later miss out on the ratings of the middle and high schools they are assigned to.

Equity factors are also included. This looks at whether students from various backgrounds, including low-income students, are achieving good outcomes. If the overall average is high but a specific group's performance is significantly lower, this can negatively impact the score.

One more thing to keep in mind is that GreatSchools scores can only be compared within the same state. A school with a score of 9 in Massachusetts does not mean it will also have a score of 9 in another state. Since testing standards and curricula vary by state, if you are moving from another state, bringing the same score expectations can lead to misunderstandings.

Therefore, it's not necessary to take the difference between a score of 10 and 9 too seriously. What's more important is to look at trends over the past few years—whether the ratings are improving or declining. A school doesn't maintain a good score indefinitely. If teacher turnover increases or student enrollment suddenly rises, the rating may drop in the next evaluation.

You should also consider the student-to-teacher ratio. Even with the same score of 10, the quality of the actual classroom experience can vary depending on how many students are in each class. Parent reviews can also be insightful. They often contain information about the atmosphere that isn't reflected in numbers, such as the communication style of school administration or the actual operation of after-school programs.

The most important thing is to verify the address of the assigned school. In popular districts like Lexington, it's common for school boundaries to be divided by just one road. If you find a home you like, it's safest to check directly on the Lexington public school website or with the school district to see exactly which school your address is assigned to. The school district information displayed on real estate sites is for reference only and may differ from the actual assignment.

If you are in the process of comparing multiple listings, repeating this verification process for each potential home can prevent confusion right before closing. In areas like Lexington, where a school district premium exists, school scores often reflect in home prices. Therefore, it seems safer to check not only the scores but also the trends and assigned school addresses before making a decision. This article is not investment or legal advice, and it is recommended to consult a professional before finalizing any contracts.