I believe I’m a reasonably objective grader, but if I wasn’t, would I know? Most everyone thinks they’re an above-average driver too.
It helps that, in my field, many responses are right or wrong; programs work or they don’t. Of course, I award partial credit for programs that partly work, or responses that are “on the right track,” so then it becomes fuzzy. I often use what one could (charitably) call a rubric, to help keep track of criteria and standards. But still, is it fair?
I’d like to think so, but one thing raises alarms. I notice myself doing it from time to time. In the midst of grading an exam, I’ll encounter a response so mystifying (or so brilliant – it can happen!) that I’ll flip to the front page as I ask, “who is this?” Does the score I award depend at all on the answer to that query?
Maybe in the future I will try blinding exams and significant assignments in some course, to deny myself the answer.