Extrinsic motivation :-) Set up some system in which she gets something she wants (in our house it's game-minutes, i.e. entitlement to spend minutes playing computer games) for doing things correctly, but not for doing them incorrectly even if "only" through carelessness. Then don't rub it in - it's just the impersonal system that determines she has to do stuff right if she wants < whatever >. You'll need to think about scale quite hard - it shouldn't be so easy to accumulate reward that losing a bit through carelessness doesn't matter, but you also don't want one tiny mistake in a lot of correct work to be devastating...
These days we typically get DS9 to propose and then monitor his own system, which works well though wouldn't have done when we started. Examples: he gets 1, 3 or 5 (depending on level) game minutes for an Alcumus question done correctly first time without help, and when he does a 90-minute maths competition practice paper, he gets 10 game minutes for a good concentrated effort regardless of result, and then an extra minute for every question correct above an agreed baseline. Something like the latter system might work well for you? I think it's important, probably, to count positively - get something for correctness, not have something by default and lose it for mistakes.
I do have a lot of time for Kohn's argument that all such schemes are evil, but they work too well to eschew! I've discussed these arguments with DS more and more and, interestingly, he chose not to have his AoPS challenge problems in the system.
Last edited by ColinsMum; 09/07/13 12:23 AM. Reason: adding detail
