Konrad Glogowski doesn't post in his blog often, but when he does it's so very thoughtful, i.e., this was posted in October (yes, I know, I haven't been actively posting in my blog either!) This is just a partial post; you need to go to his blog for all the information: blog of proximal development � Blog Archive � They Begin to Build Bridges.
"We have started a long novel study unit and the students will soon have to start working on major unit projects. The idea is to give them the freedom to explore the novel on their own, to make connections between the novel and any current or historical events, and to spend some time becoming an expert who will then present a specific aspect of the novel to the whole class. The question I am considering, though, is whether to make this an individual project or a group one. I think I understand the advantages and disadvantages of both but, as my previous post makes very clear, I am deeply suspicious of groups. I understand that we are social animals, that students need to learn to work collaboratively, that ideas grow when minds work together, and that team work is a highly prized skill out there in the “real world.” Yet, at the same time, I know that more often than not, when students work in groups many individual voices are subordinated to the dominant voice of the group."...
This post has several comments from others making for interesting reading.