My DS15 did Tae Kwon Do for a few years, and they had a policy (unwritten, but it was made known to the parents when we signed up) that the instructor got to see all "Friday Folders" and report cards. They never said the grades out loud, and they always looked more at the teachers' comments about effort and behavior than number/letter grades. Those with bad reports had to do extra push-ups and live with knowing they had disappointed their instructor while those with good reports got praised by the instructor; the kids who had had a bad report then improved it really got praised. DS is easily embarrased and felt awful about disappointing his Master, but it really motivated him to work harder, and the praise he got for improving made him feel on top of the world. It really made an impact on his work ethic and the effort he made at school. Did it seem a little harsh to me at first? Yes. I quickly saw the difference it made, though, and it made me realize that today's kids are too often handled with kid gloves, and it isn't good for them in the long run. They also asked parents every class if their child was behaving at home, and the same "punishment"/rewards applied. It made a big difference at home, too, and he once admitted that all of that made him feel like the instructor really cared about him as a person instead of just his MA abilities.
It got to be that the drive was too much, and we couldn't find a closer school, so we quit, but I would love to be able to get him (and my other sons) back into it.
Jennifer