[gruez]

>You're either at a third grade level or not. This adjustment seems to have no purpose other than completing a narrative that does not help solve the problem.

How should you measure an education system? Should you measure purely based on the student's performance? What if the students are just better at reading, independent of the school? It's not hard to imagine that even with identical teachers, that inner cities schools would have worse test scores than wealthy suburban schools, especially if the latter are rich enough to afford tutors, the family environment is more conductive to learning, etc. Recognizing this fact, it's fairly obvious that "you're either at a third grade level or not" is a terrible way of assessing how good of a job an educational system is doing.