Mid-air gestures offer a promising way to interact with large public displays. User representations are important to attract people to such displays, convey interactivity and provide meaningful gesture feedback. We evaluated two forms of user representation, an abstract skeleton and a silhouette, at a large public information display. Results from 56 days, with 190 sessions involving 483 detected people, indicate the silhouette attracted more passers-by to interact and, of these, more engaged in serious browsing interactions. By contrast, the skeleton representation had more playful interactions. Our work contributes to the understanding of the implications of these choices of user representation.

This paper describes the design and evaluation of our Media Ribbon, a large public interactive display for browsing hierarchical information, with mid-air gestures. Browsing a hierarchical information space is a fundamental form of interaction. Designing learnable mid-air gestures is a current challenge for large display interaction. Our in-the-wild evaluation draws on 41 days of quantitative log data, with 4484 gestures detected, and qualitative data from 15 interviews, and associated video. We explored: whether our design enabled people to learn the gestures; how our tutorial and feedback mechanisms supported learning; and the effectiveness of support for browsing hierarchical information. Our contributions are: (1) design of large public display for browsing of hierarchical information; (2) with its gesture set; (3) insights into the ways people learn and use this interface in our context; and (4) guidelines for designing learnable mid-air gestures.

New forms of natural user interfaces, particularly tabletops, are now a possibility due to the staggering advances in sensing and display technology. There is an immediate need for corresponding progress on the foundational software for exploiting the potential of these new hardware products. This requires research into natural and effective gestural interaction, with careful consideration of the core facilities needed for effective and consistent use. At the same time, an exploration of real-world tabletop applications will provide a basis for studying and advancing the core functionality.