It's the variability, stupid.

Just a brief post and a promise to start blogging again soon (should anyone, actually, ever read this).

Class participation grades have been a topic of much discussion among my classmates. Depending on the course, class participation can make up as much as 30% of your final grade - but it's typically around 20%.

The promise of easy marks hasn't been enough to motivate a lot of my classmates to actually talk in class. Perhaps 20% doesn't look very important. But the key isn't the % of the overall grade, it's the variability too.

What you find in a lot of courses is that there is very little variability in exam and assignment scores - mainly because they're quite easy and your classmates work pretty hard - whereas there is huge variability in class participation scores. If you make a decent comment per class, you end up somewhere near full marks - if you're absent and/or don't say anything you often score zero.

What this means is even though participation looks like a relatively small fraction, actually it can account for an awful lot of the final variation in grades. Put your hand up and say something, it's not that hard and it might make the difference on your transcript...