A Comparative Usability Study of Physical Multi-touch versus Virtual Desktop-Based Spherical Interfaces

Physical multi-touch spherical displays can provide a direct, hands-on, embodied interaction experience with global visualization data like ocean temperatures and currents. However, current commercially available displays may be cost-prohibitive for educational institutions and/or non-profits to acquire. Virtual globe-based visualizations like Google Earth are a potential alternative, but it is not clear how well the interactive affordances of physical spheres may transfer to the virtual. We conducted a within-subjects comparative study with 21 participants who completed similar tasks on a physical and a virtual spherical interface platform, which were designed to be as similar as possible, in order to allow us to compare the interaction experiences. Our results overall showed no significant difference be-tween usability or task time on the two platforms. In their qualitative feedback, participants noticed the differences between the physical sphere and virtual sphere in terms of effort and motor demand. Our research implies that, in resource-constrained environments, a virtual globe can be a sufficient substitute for a physical sphere from a usability perspective.