Don't forget thinking they're smarter than they are. I think that most of the respondents were working based off of a school grading scale, where 6.0 is barely

Don't forget thinking they're smarter than they are. I think that most of the respondents were working based off of a school grading scale, where 6.0 is barely passing and 8.5 is average (mid-B), so to give oneself a 5 is to admit failure. The professor, on the other hand, seemed to be working on a (5, 2) normal distribution that, to make things even tougher, was based on her young, academic peers. Hence, the more modest ratings coming from her. If they had asked me, I'd have given myself a 2 for both, just to be different.