It's amazing how one new participant can change the dynamic of an established group. We're often not conscious of it until after the group has convened, when we're either congratulating ourselves for wisely choosing the new addition or grousing about how things didn't quite click. No matter the outcome, it's best to be aware beforehand that new additions will play a role -- large or small; subtle or bold -- in the interactions and outcomes of group work. Knowing that a new addition will be joining an established group, it's always useful to lay out expectations and ground rules with the individual in advance. During the meeting, group leaders will need to pay particular attention to providing more background information and insights in order to give the newcomer a chance to "catch up". Group leaders should also be mindful of ways to include newcomers in discussions by actively inviting their perspectives and posing questions for them to answer. A...