MEETING DISRUPTERS: If two participants are carrying on a personal discussion that interferes with a meeting, direct a clear and simple question to one of them. In order to avoid embarrassing them, address them by name before asking the question. An alternative is to restate a previously expressed suggestion and then ask them for an opinion.
HECKLERS: A participant with a negative viewpoint can continually undermine the flow of a meeting with snide comments or emotional tirades. Don