It is their job to ensure that everyone has the chance to state thier concerns. The facilitator should be neutral on the subject being dicussed. If they hold strong views, another faciliator can be chosen for that topic. The timekeepers job, when time is limited, is to ensure that people remain aware of how much time is passing discussing each item. Peacekeeper Peacekeepers function not only during meetings, but whenever the group is active.
Thier role is to keep order and prevent crises.
They defuse potential violence from outside the group or within it. The notestaker takes notes and ensures that they are presented to the group for checking. Coordinators should switch roles often.