Are East Cobb’s Top-Rated Schools Starting to Slip?

Many families place a strong emphasis on their children’s education and choose where to live accordingly. It’s no surprise, then, that East Cobb’s reputation for excellent public schools has long been a major driver of its real estate appeal. That reputation, however, may now be facing an unexpected challenge.

While recently researching schools for several clients, I reviewed ratings for a number of East Cobb elementary and middle schools on GreatSchools.org. To my surprise, the first four schools I checked were all rated 8 out of 10. In the past, ratings of 9s and 10s were the norm, so this immediately raised questions.

Digging deeper, I noticed something even more puzzling: all four schools had identical sub-scores:

Academic Progress: 7

Test Scores: 10

I then expanded my review to seven additional East Cobb elementary schools—Mount Bethel, East Side, Tritt, Timber Ridge, Shallowford Falls, Murdock, and Sope Creek—and four middle schools—Hightower Trail, Dickerson, Dodgen, and Simpson. Once again, every school showed the exact same rating pattern.

To better understand this, I reached out directly to GreatSchools. I was told this does not indicate that East Cobb schools are declining in quality. Rather, GreatSchools believes academic growth has “plateaued” at several feeder schools. Their current model prioritizes student growth over absolute test performance, and the scoring bands are broad enough that very different schools can end up with the same rating.

GreatSchools defines academic progress (or growth) as how much students improve year over year. They place greater weight on this measure because they believe growth is less correlated with socioeconomic background and is therefore a better indicator of a school’s impact, than testing scores.

I also checked  East Cobb’s flagship high schools—Walton, Pope, and Lassiter. All three continue to hold 10/10 ratings, with test scores rated 9 and college readiness rated 10. At least at the high school level, East Cobb still appears to perform at an elite level.

Still puzzled, I asked GreatSchools to provide examples of nearby schools with higher or lower academic progress scores. Here are some results from the Marietta area:

Austell Elementary: 7/10 (Progress 9, Test Scores 5)

Birney Elementary: 7/10 (Progress 9, Test Scores 4)

Lindley Elementary: 7/10 (Progress 9, Test Scores 5)

Fair Oaks Elementary: 7/10 (Progress 9, Test Scores 4)

Garrison Mill Elementary: 9/10 (Progress 9, Test Scores 10)

Due West Elementary: 9/10 (Progress 9, Test Scores 10)

All of this raises important questions. Schools are now judged heavily on “growth,” but how is that growth truly measured? Much like Zillow assigns a value to a home, GreatSchools does not review individual student records or conduct interviews, they have no real data to make those decisions. Growth appears to be inferred entirely from standardized test data.

If East Cobb schools already post near-perfect test scores—and have done so for many years—logic suggests their year-over-year improvement would naturally be smaller. This is a familiar concept in economics and business: the better you already are, the harder it is to improve. Yet schools like Due West , and Garrison Mill defies this consept by showing both top test scores and higher growth ratings. So unless these two schools had low testing scores  and now it’s 10, which can explain the 9 in academic progress, these ratings don’t make sense. 

Even more troubling is the uniformity. How can nearly all East Cobb elementary and middle schools show the exact same academic progress score? Do they have identical faculty quality, student populations, and outcomes? That seems highly unlikely.

Whether this reflects a methodological flaw, data limitations, or an unintended consequence of GreatSchools’ evolving model, the outcome is clear: East Cobb elementary and middle schools now appear, on paper, to be declining. Compounding the issue, GreatSchools does not publicly display historical ratings, making meaningful year-over-year comparisons impossible for the public.

If GreatSchools continues to play a major role in how families choose schools, its growing emphasis on a debatable measure of “growth” over performance could significantly influence how East Cobb is perceived—especially by relocating families who rely heavily on these ratings.

Whether this is an early warning sign or simply a shift in measurement remains to be seen. Either way, it is a conversation worth having in a community where educational excellence has long been a defining strength.