Hi Dennis:
Fair and consitent, for me, describes the best reason for setting up a grading rubric. Also, although you sort of touched on this, students can determine in advance how much effort and to a degree, what grade they want to try to achieve. I have to say, I have still have had students argue my decision on what level they performed. Just to say, rubrics are great because they're objective - but not perfectly so.
Regards, Barry
