A test is supposed to help the teacher. The teacher is supposed to see if there is an item or items that were missed by several students. If that’s the case, then the teacher needs to reteach the material covered in the question(s). Maybe, it needs to be presented to the IEP Committee, not in the IEP, that if other students are failing then the material needs to be retaught to everyone who didn’t pass the test. Then, everyone needs to be tested again. The teacher(s) can test over the same material but with a different test. The same thing is true for assignments. If a lot of people are failing assignments and assessments, the problem isn’t the students or your child’s IEP.