ProxemicUI: object-oriented middleware and event model for proxemics-aware applications on large displays

Interpersonal spatial relationships ("proxemics") play an important role when people collaborate or work near one another. While state-of-art tracking systems and toolkits have been demonstrated that are able to provide proxemics data, application developers require the ability to define their own custom proxemics events (i.e., the meaning behind specific spatial configurations) rather than conduct manual tests in the UI layer. At the same time, proxemics-aware applications involving shared displays need mechanisms to tightly integrate UI events and proxemics events. This requires a middleware framework that allows developers to define proxemics events by composing low-level proxemics data and optionally UI events. In this paper, we present a proximity-based event model suited to collaboration around large displays, and a corresponding framework for building proxemics-aware applications. The design of this model is derived from a review of prior work, and direct experience implementing and evaluating a proxemics-aware interactive tabletop application (a museum information kiosk).