The data isn't very strong to support the idea that leaving advanced kids in the room with those that need more attention is of any help, and there is now growi

The data isn't very strong to support the idea that leaving advanced kids in the room with those that need more attention is of any help, and there is now growing evidence of achievement gaps widening, possible because it can be demoralizing for the slower kids, possible because the more advanced kids are now more likely to get outside supplementation which boosts them even further ahead.