It accomplishes little. The tests are a subset of the things the students should have been learning anyway. The idea was that by measuring performance teaching could be improved where needed. The actual result was that the "help" given to classes with bad scores has been to overtrain some tiny neural nets to respond to very specific stimuli without teaching them anything beyond the specifically measured behavior. Even the students that pass often haven't mastered the material. They just can take the test. We opted to replace accountability with process and reaped the usual results.