I've never advocated for cluster grouping; however, our whole sd has gifted clusters in every grade from 2-5, then gifted classes in middle school and high school. The gifted cluster classrooms in elementary school are supposed to have from 5-8 gifted kids in each, with the ballance of kids made up of average or above students. The gifted classes get inclusion with the gifted teacher (the gifted resource teacher comes in and does enrichment with the whole class). Does it work well? From what I can tell, a good class is more teacher-dependent than gifted-cluster dependent. (The rest of the classes at a particular grade level are supposed to include kids of all abilities.)
