Since the ultimate purpose of a dialogue may be to accomplish something in the world, not only in the minds of the participants, reasoning, goal-directed planning, and action need to occur at the domain level as well. The goals of speech acts are then not ends in themselves, but means to other ends in the domain, perhaps to be accomplished by physical action (such as equipment repair). As a result, task-oriented dialogues are apt to be structured in a way that follows or “echoes” the structure o