Just an idea, might be completely flawed. I would put together children in "interest groups", not by age, but by the field that they should (or are interested

Just an idea, might be completely flawed. I would put together children in "interest groups", not by age, but by the field that they should (or are interested to) learn. There would be a defined curriculum in each of the fields, and each kid would have a certain level in each field, which would be certified by exams, and they would be encouraged to work towards those exams. (Say every half a year, you would get a level if you pass an exam.) There would be no marks, only levels, up to unattainable mastery. Within each interest group, children of different levels in that group would intermingle. The children with lower level of skill would respect (follow instructions of, do not bother, etc.) children with higher level of skill. On the other hand, the children with higher level of skill would have obligation to also mentor and help the children with lower level of skill to get to the next level, and not to be judgemental about one's skill level. Everybody would have an obligation to learn (or practice) and get to the another level. The whole operation would be partly supervised by adults, ideally people with the high level in the particular skills.