A Visual Method for Robot Proxemics Measurements Tim van Oosterhout Instituut voor Informatica, Universiteit van Amsterdam Kruislaan 403 1098SJ Amsterdam, The Netherlands tjmooste@science.uva.nl Arnoud Visser * Instituut voor Informatica, Universiteit van Amsterdam Kruislaan 403 1098SJ Amsterdam, The Netherlands arnoud@science.uva.nl ABSTRACT Human interaction knows many non-verbal aspects. The use of space, among others, is guided by social rules. Not conforming to these rules may cause discomfort or even mis- communication. If robots are to interact with people, they must follow similar rules. The current work tries to identify factors that influence human preferred interaction distance in conversation-like interaction. For the measurement of interaction distances an accurate and objective visual method is presented. In this method, the researcher does influence the results by disturbing the interaction. It is found that subjects choose interaction distances compa- rable to those in human interaction. Variations are mostly explained by subject age and, depending on age, by gender or robot appearance. This is the first time, to our knowledge, that a clear age and gender effect is found in human-robot interaction-distance. Categories and Subject Descriptors I.4 [Computer Applications]: Social and behavioral sci- ences— Psychology ; I.2.9 [Artificial Intelligence]: Robotics— Commercial ro-bots and applications ; H.5 [Information Sys- tems]: Information Interfaces and Presentation (e.g., HCI)— Benchmarking General Terms Measurement, Experimentation, Human Factors Keywords Proxemics, Human-Robot Interaction, Visual Measurement * The authors were supported by EU Integrated Project COGNIRON (”The Cognitive Companion”) FP6-002020. 1. INTRODUCTION Advancements in artificial intelligence enable the creation of more intelligent robots that can perform a greater array of tasks, making it more realistic and even desirable to bring them into the house or office. People are social beings how- ever, and human interaction is guided by social rules. While people can learn to adapt to robots, the robots should be made to follow similar rules that will make the interaction natural and require no extra effort on the human part. The current research tries takes an approach from the sociologi- cal concept of proxemics. Recent research has indicated the influence of robot ap- pearance [4], subjects’ personality [8] and type of inter- action on the interaction distance. The typical setups of those experiments were inside the laboratories, where col- leagues/volunteers got clear assignments about the type of interaction that should be started. The research reported here is performed in a free setting during an arts and tech- nology festival, with the subjects unaware of the experiment performed. This resulted in a large number of interactions, with variety in age and gender which is difficult to reproduce in robotics laboratories. 1.1 Proxemics The field of proxemics is concerned with interpersonal dis- tance and personal space. The term was coined by the an- thropologist Edward T. Hall in his 1966 book the hidden dimension. In this book, Hall uses findings from the animal kingdom and insights in human experience of space to define four personal spheres. These spheres define areas of physical distance that correlate reliably with how much people have in common (cultural difference). Where the boundaries of these spheres exactly lie is additionally determined by fac- tors such as gender, age and culture [2, 3, 5]. When one comes too close to another, the other may feel crowded or intimidated. If, on the other hand, one stays too far back, this is seen as awkward and one may be perceived as cold or distant. Appropriate distances found by Hall in western culture for adults of both genders are displayed in Table 1. 1.2 Human Interaction To explain the locations of these boundaries, Hall theorizes that they coincide with the boundaries of sensory shift. At different distances, touch, vision, hearing but also smell may be optimal, distorted, or not available at all. Physical prop- erties also come into play, such as an arm’s length, which defines the distance from where one can touch the other,