Education Ability and Time Limits

In her article, "Education Ability Doesn't Have Time Limits", (http://www.huffingtonpost.com/julie-woestehoff/education-accountability-time-limits_b_792090.html) author Julie Woestehoff has some intriguing ideas about promoting/flunking children and not placing them in a classroom based on their age.  Her proposal of moving students along to the next level when they have proven mastery of the current level is contrary to all public school systems in the U.S. and is an idea that should be tested.  Think about this -- kids wouldn't be stigmatized by the label of having "flunked" or "held back", they simply haven't achieved mastery yet.  If their friends have moved ahead, it might provide more impetus for them to work harder to do the same.  Of course, the entire standardized testing system would have to be scrapped, and who would be happier about that -- the students or the teachers?!!!!