When you're in college (and often in high school), classes are
often graded on a curve. This means,
generally, that scores will be adjusted to account for the
difficulty of the assignment; professors can't always
write perfect tests.
And about once a year, at the end of a quarter/semester, you'll
notice that, in one of your classes, everyone's talking
about the final. Someone's had a light bulb moment, and now there's
some brilliant idea going around the class, and eventually
you get someone to tell you what it is.
The reasoning invariably goes like this (in an
- He's grading on a curve, right? So no matter how low the
average score is, the average grade will be the same,
- So, like, if everyone got a 0 but one guy got a 5% that guy
would get an A!
- And if everyone got a 0, we'd all get A's!1
- So we're gonna get everyone to skip the final!
And the professor shakes his head sadly and says it
wouldn't really work like that, but can never give a satisfactory
This year, though, this happened in my computer science
lower-division logic class. And the professor, being a rather smug
person to begin with, said, "Sure! If none of you show up, I'll give
you all A's."
There was a hushed silence.
he added, "you'll never convince everyone to not come."
Naturally, most of the class started arguing: "Well, of course
they'll stay home! They'll get an A!" Or, "Fine, we'll hire some
bouncers to stand outside the door, then!"
But if you think about it, he's right. It's a classic example of
the Prisoner's Dilemma. The greatest good for the community will be
obtained if everyone stays home, but nobody can trust that every
single other student will stay home. And if even one person comes in
to class, the whole thing is ruined - everyone gets an F extept that
one serlfish jerk, who gets an A for answering even one question right.
So everyone says to themselves, "Well, I'm not going to be a
sucker. I'll go take the test." They have to act in their own best
interest, because they expect everyone else to do so too.
I'd love to stick it to that smug bastard professor, but of course
he's right. We can't trust everyone to not come. I expect I'll see
everyone at the final next week.
Of course, this is an
idea. But really that'd make the maximum
a 0, and everyone's personal score would be a 0. 0/0 isn't really an A,
and there's no checkbox in the grading program
". If the whole class got a 0/0, we'd risk destroying the
with a divide by 0 error
. It's a
small risk, to be sure. But just in case, I'll go to the final.