Public displays have the potential to reach a broad group of stakeholders and stimulate learning, particularly when they are interactive. Therefore, we investigated how people interact with 3D objects shown on public displays in the context of an urban planning scenario. We report on an elicitation study, in which participants were asked to perform seven tasks in an urban planning scenario using spontaneously produced hand gestures (with their hands) and phone gestures (with a smartphone). Our contributions are as follows: (i) We identify two sets of user-defined gestures for how people interact with 3D objects shown on public displays; (ii) we assess their consistency and user acceptance; and (iii) we give insights into interface design for people interacting with 3D objects shown on public displays. These contributions can help interaction designers and developers create systems that facilitate public interaction with 3D objects shown on public displays (e.g. urban planning material).

Keywords: public displays, gestural interaction, elicitation, urban planning