Why do we assign grades? I suppose they are to provide a concise snapshot of a person's understanding at a given point of time. The problem with this is that learning is fluid, and grades are static; it is like trying to take a movie of your life by snapping a photo once a week. It may show some overall trends but the nuances are completely lost.
Another problem that arises is that students seem, on the whole, to have lost sight of the forest for the trees. A grade should be a tool, albeit a poor one, to track progress, but it seems that for so many students it is an end in and of itself. The attainment of the letter matters more than the reason (i.e. understanding and internalization of a concept) for that letter.
I see in education at the moment a couple of strands that attempt to address this issue. On the one hand, there is the idea of "gamification." I won't profess to be an expert on this subject, but at its core, it seems, is the idea that people are naturally imbued with a need to gain status and rank for their achievements. As in a video game, where experience points and medals are awarded as a person progresses through levels and does various tasks, the "gamified" classroom awards experience points and medals for tasks done relating to the subject matter.
The other strand is the idea of standards-based curriculum and the use of rubrics. Students should be able to clearly see expectations and strive to attain them. In fact, these two strands are not dissimilar; each views education as a series of steps, with checks and balances to make sure students don't go too far off course.
But this is my concern; these approaches are still external motivators. The gamified classroom may make the process of learning more enjoyable and engaging, but the student is still striving for those "experience points" and medals. The rubric may clarify the inner working of an assignment, but the student is still thinking "what can I do to get that 3 or 4?" We've swapped out the grades of A, B, and C for new set of codes.
And here is my point. I think true learning is undefinable by its very nature. True learning is internally motivated, born out of intellectual curiosity and a need to know "why?" The true learner doesn't stop to ask what their grade is; the only thing that matters is knowing enough to ask more questions. These are the people that become creators and innovators (take, for example, Bill Gates, who dropped out of college.)
This sort of curiosity can't really be objectified or pinpointed to a rubric. Imagine a rubric strand that asked a teacher to rate a student's inner drive and curiosity. Until we develop the ability to read people's minds, this is untenable.
So I come back to my initial question. Why grade? I would like to hope that it is the view of every educator that they be able to instill that intangible curiosity in all of their students. And, if grades are the only vehicle to even attempt to surmount the insurmountable, I'd rather have a rickety wagon than nothing at all. But I also wish there was a better way to get students to see that its not the grade, stupid, nor even the subject matter, but the thirst for learning.
With that, I leave you with this gem from Ted-Ed: