Earlier quoted context omitted.
Would be very interested if you could find a link (had brief unsuccessful look myself)
http://www.wired.com/magazine/2011/07/ff_khan/all/1 the very end is about a proposed private school "For his part, Khan says he’s now considering starting his own private school, as a way to see just how much you could wrap learning around Khan Academy. His ideas are intriguing: Among other things, his school wouldn’t divide kids by age; teenagers would mix in with kindergartners. “I have no research to back this up,…
We lived in a fantastic little neighborhood, Perry Circle, in Annapolis where this was routinely observed. It very much nailed the first iteration of Alexander's Pattern Language: 10 buildings, 6 apartments in 3 stories, plus attics and below-ground garages, arranged around a central circle. Those parents who stayed home would congregate on the porches and benches and the kids of all ages would play together very constructively.
I really miss living there. It's what cul-de-sac neighborhoods could have been.