  This study presents an empirical investigation into the design and impact of
autonomous dialogues in human-robot interaction for behavior change coaching.
We focus on the use of Haru, a tabletop social robot, and explore the
implementation of the Tiny Habits method for fostering positive behavior
change. The core of our study lies in developing a fully autonomous dialogue
system that maximizes Haru's emotional expressiveness and unique personality.
Our methodology involved iterative design and extensive testing of the dialogue
system, ensuring it effectively embodied the principles of the Tiny Habits
method while also incorporating strategies for trust-raising and
trust-dampening. The effectiveness of the final version of the dialogue was
evaluated in an experimental study with human participants (N=12). The results
indicated a significant improvement in perceptions of Haru's liveliness,
interactivity, and neutrality. Additionally, our study contributes to the
broader understanding of dialogue design in social robotics, offering practical
insights for future developments in the field.
