Chances are, if you're a teacher, you are solely responsible for assigning grades to your students. Rarely is it a pleasant process. You may have taken an evaluation and measurement class as part of your teacher preparation program, but now you're in a real classroom, with real students (who have real parents) and you get to become each child's judge, jury, and in some cases, executioner. It's not one of the easier parts of teaching, because we as teachers pressure ourselves to make our grading as accurate and fair as possible.
But what is "fair"? Just as there is no perfect or even universally-agreed definition of the purpose of education, there is no common understanding on exactly what grades do and what a grade means. Every semester, just when I think I have my grading system figured out, I'll notice students with lower grades that I consider to have mastered content at higher level than some of their higher-scoring classmates. Do I let my professional judgment trump my grading system and change the grade? Why not? After all, I was the one who designed the grading scale in the first place. The grading system is flawed either way.
If grades can create such a quandary for the teacher, imagine the myriad of possible meanings they have for students. Some think grades are earned for simply turning in work. Others think test scores are the only critical factor. Still other students depend on grades to reflect their effort, absent any measured achievement. With so many interpretations, it's a wonder grades hold any meaning at all. I'll never forget the words of my mentor Bob Anderson at Florence High School. "Grades...are a fantasy." He was implying that students often knew so little about what their grade represented and what it took to raise it (especially at the end of a grading period) that grades might as well not be based in any reality at all. I always got this feeling when a student would ask, "If I do well on the test, will it raise my grade?" Not only did they not understand grading, but apparently they didn't understand how averages worked, either.
I've given grading a great deal of thought, probably due to pressure I put on myself as a mathematician to develop a perfectly fair, objective, and accurate grading system, and failing every single time. Consider this post as the first in a series dealing with multiple aspects of grading such as teacher autonomy, influences of grading software, and ethical questions presented from case studies.
As a final thought, I realize my transition from teacher back to student means I'm again receiving grades instead of assigning them. When I got my first graded paper back in my Nature of Mathematics Education class I looked at the letter grade like it was some sort of novelty. In fact, I was surprised it was there at all, and I really didn't care what it was. (Okay, maybe I would have cared if it had been lower.) What I really cared about was the comments left by my professor, and any hints on what I could have explained better. Apparently I gave up on the grading fantasy a long time ago, and I think I'll sleep better knowing so.