1: The Grader can be Someone You've Never Seen BeforeSure, the professor gave out the assignment. And sure, when the assignment was handed back, the professor talked to the class about how well they had (or hadn't) done on the test or paper. But that doesn't mean the professor actually graded the assignment. Think about it for a moment. There's no way a professor teaching 100, 200, 300, or more students in one class is going to be able to grade all those papers him or herself. And why should he (or she), when in many universities there's a stable of eager graduate students ready to take on those tall stacks of papers?
When I was an undergraduate at the University of Michigan. I took five advanced courses with the same philosophy professor. The professor always provided lengthy and detailed, even typed comments on my written work – often quite positive. The professor even went so far as to propose topics for my senior honors thesis – advice that went far beyond the call of duty. So before leaving for graduate school, I went to personally thank him for the years of thoughtful comments on my essays. "Don't thank me," he responded, "thank the guy in the brown jacket who sat in back of you in class." "Who was that?" I asked. "A grad student who's been working for some time as my grader -- he's the one who wrote all those comments." It turned out that the professor had never once read my papers or exams in any of the five courses. And had never breathed a word about his hidden, dirty secret. I felt ripped off. And I still do...