Revisiting ancient design of human form for communication avatar: Design considerations from chronological development of Dogū

Robot avatar systems give the feeling we share a space with people who are actually at a distant location. Since our cognitive system specializes in recognizing a human, avatars of the distant people can make us strongly feel that we share space with them, provided that their appearance has been designed to sufficiently resemble humans. In this paper, we investigate the minimal requirements of robot avatars for distant people to feel their presence. Toward this aim, we give an overview of the chronological development of Dogu̅, which are human figurines made in ancient Japan. This survey of the Dogu̅ shows that the torso, not the face, was considered the primary element for representing a human. It also suggests that some body parts can be represented in a simple form. Following the development of Dogu̅, we use a conversation task to examine what kind of body representation is necessary to feel a distant person´s presence. The experimental results show that the forms for the torso and head are required to enhance this feeling, while other body parts have less impact. Finally, we summarize design considerations for communication avatars.