WOW - how "differentiation" is practiced really differs! From what I've seen with my DC, a single teacher attempting to differentiate child by child within a single class, SELDOM works (blackcat - we NEED Wonderwoman!). "Whole class differentiation" is MUCH more effective (and I'll admit, you probably need decent class size to do this). That is, I've seen my DC make progress where an entire say, math or reading class of higher-achievers has its own teacher and its own separate class (and there are other levels with their own teachers during the same time, so the entire grade is broken up into groups).