Is bell-shaped distribution of exam grades evidence of success or failure to teach well and test well?

Students grade information are a rich source of information. The university administration, the faculties, the teachers, and the students, all should be given means for learning from that source. While a normal (or bell-shaped) distribution of grades can help educators and administrators interpret how students have performed on a test and provide some benefits in terms of standardization and competition, it may not be the best approach for all educational purposes. (With mixed capabilities class, the class average grade depicted by the normal bell-shaped distribution is not a proper gauge of how the class is divided into more than one group of performers and does not consistently reflect the attainment of the Course Learning Outcomes CLOs). Here, like many other educators and researchers, we advocate with Bloom for grading systems that reflect individual mastery and understanding, rather than expecting normal (bell-shaped) distribution or most unenviably forcing grades into a specific statistical model.