Erk. I don't disbelieve your claims but the very thought seems so bizarre to me.

I'm surprised by your reaction. I didn't expect you to be ignorant of the fact of the grade percentages in different fields and what students find difficult. The situation may be different in Australia, but your reaction seems to be total ignorance of the median.

The alternative is trying to learn an endless stream of teacher's passwords!

I'm told that there's an easy algorithm, maybe not for majoring in English, but for the small amount that's required of all american students: ask the other students. (this may not be fast enough for discussion, but it works for essays)