It did surprise me to learn how difficult it is to develop one method of grading. As a student, grades are not viewed as a display of how much one has learned.
Grades are often a way of showing what one can memorize and regurgitate.
A student who receives a low grade may have learned a lot in the class, but does not test well. I was also surprised at how averaging can hurt one s grade and does not accurately show one s level of attained knowledge.