I mean standardized test scores are 1 data point. Graduation rates/post graduation rates/post HS certificates/degree completion within X number of years, could all be factored in but someone has to compile that data.
We could kick out all the Special services, IEP's, English language learners, and behavior problems, but they'd have to repeal or alter the Individuals with disabilities in Education Act and see our scores go way up, but would that mean that we're doing better?