(second question!) In my class (7th grade science) we do labs at least once a week. I do my best (of course) to sit students with other students with whom I think they will work well. Students are not allowed to pick groups. The issue I had last year was I had certain students who were, because of diagnosed (and undiagnosed) behavioral problems, incapable of working in a group. They would get angry, throw things around, break equipment, etc. I would remove these students and assign them an alternate written assignment. But every lab I would let them try again because I know it's these students who need hands-on activities and group work more than anything else and I want to give them that opportunity. I'm sort of thinking of a reflection sheet to go along with the alternate assignment. After the alternate assignment they have to fill out the reflection sheet. If they don't finish it or if it's sarcastic, poorly done, etc, then for the next lab they will automatically get the alternate assignment and need to finish/re-do the reflection sheet. What sort of protocol do you follow for being allowed to participate in group lab work?