I deal with grades all the time in my work, but the more I think about grades, the more I wonder if we don't need to rethink the whole concept and maybe scrap the current system and come up with something more representative of the whole person. So why do we have grades? The obvious answer is to know whether someone passed or not. But beyond the grade, what else does a letter tell us? I have gotten A's on things that I didn't really understand. I have gotten lower grades on things that fascinated me. So what did the grade show? It showed that I gave the answer that was expected (or an unexpected answer in the case of lower grades) by the person doing the grading. That is about all it showed, except for showing how I did compared to others. That is the other part of grades that I find reductionist. We like to use grades to say that a person ranks here, while another person ranks above or below them. Of course the competive like to say that they rank above others. Grades are one way of showing that.
Grades do not show the depth of learning or understanding a person has. Grades do not show the character of the learner, merely how well the learner conforms to the expected or "standard" answer. Grades are a way to neatly measure up groups of individuals and give each person a rank. Some folks take that ranking to be the holy grail of worth, value, future success, and general happiness in life. I have known very few (if any) people that can define their success or happiness based on what grades they got. Grades are typically used to get scholarships and to take more classes after high school. Grades represent an easy (dare I say lazy?) way to slap a label on someone and not assess his or her true potential and worth.