Adaptivity of intelligent environments to their surroundings provided by the ATRACO Spoken Dialogue Manager is only one means of adaptation. Recent work in Spoken Dialogue Systems focuses on the integration of user-centred adaptation means to alter the content, flow and structure of the ongoing dialogue. In this chapter, we introduce a general user-centred adaptation cycle, accompanied by two implemented adaptation approaches focusing respectively on short-term and long-term goals in human–computer interaction. After motivating the need for short-term and long-term goals to entail different adaptation mechanisms, we provide exemplary adaptation entities for each case with corresponding experiments and implementations. The short-term goal user satisfaction allows for detecting whether the user is not satisfied with the interaction and for triggering counter measures to improve the interaction. As a long-term goal, maintaining human–computer trust attempts to keep users still willing to use the system even if the interaction was confusing
