Also, in the sharing each participant benefits from the discoveries of all the members. The primary responsibility of the facilitators is to create the optimum space for rich Dharma discussion to take place. A major factor toward that end is a feeling of safety for all. Rules about confidentiality, when the sharing is personal, should be agreed on. Another aspect of safety is monitoring the energy of the group and flow of discussion.
People vary greatly in their ease of speaking to a group.
Some are shy, others extroverted. Making sure that everyone has a chance to be heard and that a few people do not dominate is essential to healthy group dynamics. Some groups have even used a talking stick which is held by the current speaker. If there is a sense that the vitality and commitment of the group members is waning then that needs to be addressed. Perhaps all members can take responsibility as vibes watchers.