Caucus is the term used in mediation for splitting the parties into two separate rooms. We have read that the term originates from the Olgonquin Indians and refers to a counsel as in a war or peace counsel. The mediator works with one party at a time exploring options, asking questions, dealing with hurt feelings, and helping the parties to move toward resolution of a difficult issue (e.g. custody of the children).
The mediator moves back and forth between the rooms conveying proposals and counter-proposals until the parties have come to agreement on that topic.
There is considerable controversy in the field over the best way to handle mediation. Our preference is to use a combination of joint sessions and caucus.
There are occasions where we do not use joint sessions, for example if criminal behavior or physical abuse is a factor. Also, we will minimize or eliminate joint sessions if one or both parties are unusually distraught.
However, the main reason we use joint sessions is because the communication process is enhanced by hearing the thoughts, feelings, and ideas, directly from the other spouse rather than hearing it second hand.