Do your best to strictly enforce there rules.
As an observer, you may want to look for some of the following:
1. Who is willing to give away pieces of the puzzle?
2. Did anyone finish his puzzle and then somewhat divorce himself from the struggles of the rest of the group?
3. Is there anyone who continually struggles with his pieces but yet is unwilling to give any or all of them away?
4. How many people are actively engaged in mentally putting the pieces together?
5. Periodically check the level of frustration and anxiety-who’s pulling his hair out?
6. Was there any critical turning point at which time the group began to cooperate?
7. Did anyone try to violate the rules by talking or pointing as a means of helping fellow members solve their puzzle?