by David Safier
I'm not often in agreement with the Arizona Charter Schools Association, a well funded group whose purpose is to promote charter schools in the state, but for once, we're in sync. We both have problems with the current A-F grading system for Arizona public schools, district and charter.
In a detailed, scholarly analysis, the Center for Student Achievement, a part of the AZ Charter Schools Association, shows how the current school grading system is heavily weighted to make schools with high income students come out near the top and schools with low income students come out near the bottom. The reason is, half of a school's grade is based on the average student AIMS score, which tends to raise with students' family incomes. The other half is based on student growth — the rise in students' scores from one year to the next — which is far less economically biased. Unfortunately, the growth portion doesn't counterbalance the economic bias built into the schools' average AIMS scores.
The study doesn't recommend abandoning school grades. It suggests a revised grading system that relies on a number of variables related to student growth. It's complicated, and I don't know enough about the numbers to evaluate it, but it certainly would create a more level playing field than what we have now.