Social signals are commonly used to facilitate the usability of humanoid robots. While providing the robot with an extended expressibility, these signals are often applied only in structured interactions where parts of the familiarization or farewell processes are disregarded in the evaluation. In order to establish the consideration of a more comprehensive view, this article presents a holistic model of human encounters with a social robot. We propose and discuss particular robot signals, which aim to express the robot's social awareness, for each of the model's phases. We present an interaction study with humans that are inexperienced in interacting with robots to investigate the effects of these signals. Results verify that the implementation of proposed signals is beneficial for the participants' user experience. The study further reveals a strong interdependency of a robot's social signals and the importance of addressing entire encounters in human-robot interaction studies.
- Holistic human–robot encounters
- Nonverbal signals
- User study