We've not seen in-class differentiation done well yet. I hear it exists.
ConnectingDots beat me to it. We started my son's schooling off with "differentiation" - he was in a 1st grade math class for K where he was way beyond all 1st graders and was blurting out answers before anybody else - and they gave him "work packets" sporadically - but, these work packets did not come with any instructions or teaching by the teacher. The teacher said that differentiation meant that they will provide challenging work, but they had no time to teach new concepts and expected the child to already know them.
We moved to a school which gave him a 1 year acceleration in math - too slow paced and boring for him.
We moved to a school that placed him in a special class (ability grouping) where kids were accelerated 2-3 years in math - he is happier now - a lot of the kids are hothoused and go to evening classes in math centers, but, he has met 5 kids who are at the same level in math as him - they are his peers and he is feeling competitive and energized in class because he enjoys the interactions with them.
This placement is not perfect, but we appreciate that DS can meet kids who have as much passion for math as him.
We are continuing to after school in his strength areas, because he has the ability to handle more than what the classroom provides, but, he learns a lot in the class as well (this year, he has been learning geometry and it is new to him, though he gets the concepts quickly, he is thrilled to learn something new at school).
Differentiation in the class room did not work. But, we have had some success with a combination of "ability based grouping" and after schooling.
