In my brief reading on the subject, I remember there being a welter of different ideas of how cluster grouping, cooperative learning, etc. should be implemented and how well such strategies would work. I know that there is at least one model out there where underperformers were recommended to be placed with high achievers, but I can't find it right now. I have the "Encyclopedia of Giftedness, Creativity and Talent" by Barbara Kerr on inter-library, inter-spouse loan right now, and will see if I can find anything in there. The third link below suggests that gifted kids clustered with low achievers suffer no ill effects, but the self-concept of the other kids suffers.
http://www.nagc.org/index.aspx?id=162http://www.susanwinebrenner.com/handouts/schoolwide_cluster_grouping_model.ppthttp://www.gifted.uconn.edu/nrcgt/kennarch.html
