GreatPhillySchools has compiled school ratings from data provided by the Pennsylvania Department of Education, the School District of Philadelphia, the Archdiocese of Philadelphia, and the National Student Clearinghouse. We have made every effort to use the most official and current data for each school.

If there were errors in the official data source, then those errors could affect the ratings produced by GPS. Also, it is reasonable to expect that not all data collected by these institutions were tabulated in exactly the same way: For instance, on safety, some schools might count a fight between third graders as a serious incident and others might not. On attendance, some schools might mark a student who misses one period absent for the entire day; others might not. We have strived in all categories to use data that is comparable. But because much of this data starts with a person making a decision about how to record an incident, and because different people will make different decisions in similar circumstances, we must recognize that a 10-point rating scale cannot reflect small differences between schools with great clarity or precision. That’s why GPS ratings are meant to be guides, not final judgments.