The GreatSchools.org Dilemma: What That 1-10 Rating Really Means for Boston Homebuyers

The 1-10 school rating on Zillow isn't simple quality measurement—it's a weighted algorithm that recently removed equity metrics and can rate schools on test scores alone, the metric most correlated with family income, not teaching effectiveness.

Homebuyers using GreatSchools ratings to filter neighborhoods and justify price premiums.

• •GreatSchools ratings combine three metrics with different 'strength scores' and changing methodology
• •July 2025 update removed equity ratings entirely from summary score calculation
• •Schools can receive 1-10 rating based solely on test scores despite low 3/5 strength score
• •Student Progress rating (5/5 strength) often invisible despite being least income-correlated
• •Same school can be 10/10 (test scores) or 6/10 (growth)—first number appears on listings