Grades can, without hesitation be called a necessary evil. Mostly, they are evil, but they are also, for some purposes necessary, and unfortunately, that means that a few of their virtues are easily overlooked. Allow me to explain.
But before I do that let me say that the best system — for learning, at least — would be one in which we gave serious and frank narrative evaluations and skipped the grading altogether. Unfortunately, that (1) takes a lot of time, (2) can be challenging to communicate to the outside world, (3) flies in the face of a lot of culture, which means that (4) there's a constant tendency to slip back into grades anyway. In my undergraduate institution — which had no grades and only narrative evaluations — students were known to sometimes count adjectives and compare.
But the point still needs to be made: as a learner, what you want from instructors is information — what parts of what I did here are on the mark and what parts could be improved how? You don't want an A, you want helpful feedback.
One evil aspect of a grade is that it represents a stunning loss of information. Reducing the answer to questions like "how was my performance?" and "how much did I demonstrate that I have learned?" to a one dimensional scale with perhaps 13 values each of which comes with an error bar is throwing away hundreds and perhaps thousands of bits of information. Three performances, one with a single serious calculation mistake, another with confusion over several definitions, and a third that was more or less correct but unprofessionally prepared might all be tagged with an identical A- but the performances are qualitatively completely different.
It is interesting how often people who claim to be qualitative in their inclinations are the most eager to know "what did I get?!"
Most people cannot detach grades from the self. We ask "what did you get?" but we feel "how did she grade me?" Both are off the mark: a grade is an assessment of an artifact — an exam, paper, or exercise — of a performance at a particular point in time by a particular person. The world of education — and most of the rest of the world, for that matter — have some faith that the performance reflects the learning and so the grade can be taken as a measure of the learning. But almost nobody believes that it represents the learner. But it's very hard for us to separate our selves from that number or letter.
POINT 1, then: a grade is the subjective assessment by a relative expert of an artifact that is a performance by a learner.
Everyone wants to get an A. Less than an A is insulting. But, again, grades are not meant to be part of an emotional transaction. Grades as we use them are shorthand for an ordered set of assessments of a performance:
| A | Excellent | exceptionally good; extremely meritorious; superior; of the highest quality; very good of its kind ; eminently good |
| A- | Very Good | |
| B+ | Good | Having the qualities that are desirable in a particular thing; better than average or satisfactory |
| B | Adequate | Satisfies the requirements of the task, acceptable |
| B- | Unsatisfactoryish | Falls distinctly short of adequate practice |
| C | Unsatisfactory | Not acceptable as demonstration of competence |
| D | Dastardly and Despicable | Strongly suggestive competence has not been acquired yet |
| F | Failure | Demonstrative of competence nonacquisition |
Now, we live in a world in which performances that yield less than an A require an explanation or move us to try to negotiate for a better grade. This is ridiculous. Most of us do not produce "A" work (that is, outstanding and excellent work) much (even most) of the time. If we happen to be gifted at "producing what the teacher wants" (and getting lots of As) we may well never be challenged to exceed our current level of competence. If we don't make mistakes and have them caught, we'll never get better at things.
If you write out you answer to a question just once, if you present calculations only in the raw form in which you actually carried them out, if you submit the first version of a paragraph that you right, it is almost certainly not A work.