My son is a very able student in year 8, but rarely does any of the "Optional Extension Activities" that are set because they have the word optional attached to them. We were watching a tv programme the other day where a teenager was doing an "Extra Credit" activity. I asked DS if he'd be more inclined to do the tasks if his school used the same term and he said yes, "because it sounds like you're being rewarded for it rather than it just being extra work for the sake of it". I think it might play to his competitive instincts a bit more.
What do they call it in your school and do you think it matters?
I'd love to know if there's any research been done around this.