Sensory Perception & Interaction Research Group

Small, high resolution touchscreens open new possibilities for wearable and embedded applications, but are a mismatch for interactions requiring appreciable movement on the screen surface. For example, multi-touch or large-scroll zooming actions suffer from occlusion and difficulties in accessing or resolving large zoom ranges or selecting small targets. Meanwhile, emerging technologies have the potential to combine many capabilities, e.g., touch- and proximity-sensitivity, flexibility and transparency. A current challenge is to develop interaction techniques that can exploit the capabilities of these new materials to solve interaction challenges presented by trends such as miniaturization and wearability such as tiny screens that only one finger of one hand can fit on. To this end, Zed-zooming exploits the capabilities of emerging near-proximity sensors to address these problems, by mapping finger height above a control surface to image size. The EZ-Zoom technique adds the pseudohaptic illusion of an elastic finger-screen connection, by exploiting non-linear scaling functions to provide a usage metaphor. In a two-part user study, we compared EZ-Zoom to touchscreen standard pinch-to-zoom on smartphone and smartwatch screens, and found (a) a significant improvement in task time and preference for the smallest screen (equivalent task time for the smartphone); and (b) that the illusion improved users’ reported sense of control, provided cues about the interaction’s spatial extent and dynamics, and made the interaction more natural. From our experience with the study, we conclude requirements for the development of proximity sensors in order to afford such interactions. Our work goes on to reflect on how zed-zooming can be incorporated into seamless interaction tasks. We aim to identify some characteristics of a zooming interaction that would need to be considered when designing a complete one, and explore how these characteristics play into a complete and usable zooming interaction.