Enriching the Human-Robot Interaction Loop with Natural, Semantic, and Symbolic Gestures

In this chapter, we are discussing the appearance and need of gestures as feedback strategy for humanoid robots in interactions with humans. Gestures are a means of communication that is nonverbal, which either supports or replaces the verbal communication, and represent a rich source of communication short cuts. We are discussing the necessity of deliberation behind the use of gestures, as well as the different levels of granularity in them. We are proposing a new definition and categorization of gestures. This will lead us to a discussion on the need of further investigation of gestures as feedback strategies and how it supports the interaction loop in HRI. Finally, the chapter will categorize the state of the art in humanoid gesture capabilities and propose next challenges.