Exploring the Effects of Virtually-Augmented Display Sizes on Users’ Spatial Memory in Smartwatches

The small display size of the smartwatches makes it difficult to display large amounts of information on the device. Prior work explored leveraging a second device (e.g., Head-mounted displays) to extend the space where users can access large information space with virtual displays anchored on their wrists. Though researchers showed that having an additional virtual screen increased information bandwidth, little is known about the effect of virtual display sizes on users’ performance. In this paper, we examined the impact of display sizes on spatial memory, workload, and user experience to better understand the prospects of virtually-augmented displays for smartwatches. Results from a user study revealed that a 4.8 inches display size can be the “sweet spot” for the virtually-augmented displays to ensure improved spatial memory performance and better user experience with less workload. Finally, we provided a set of design guidelines focusing to display size, spatial memory, user experience, and workload for designing virtually augmented user interfaces for smartwatches.