This sounds a little like the "mastery-based" approach my son's private school takes. All kids are assessed at the beginning of the year and throughout the year with pretesting to determine what they have already mastered in language arts and math. Mastery = 80% or higher. A student that shows mastery can move on, so that my son was able to work 4-5 years ahead in spelling, vocabulary and grammar and 2 years ahead in math. The school is able to make this work by keeping class sizes small (10-12 students). It has worked beautifully for us.
