Investigating user performance and preference for two magnitude levels of size and angle of bend on a smartphone-sized flexible device

In the field of human-computer interaction, deformable user interfaces are gaining more attention. Gestures performed by bending the deformable device are commonly investigated in the literature. These bend gestures' inherent tactile and kinaesthetic feedback and their association with spatial directions benefit both blind and low vision (BLV) and sighted users. Bend gestures are naturally associated with two descriptors of bend, which are location and direction. One potential opportunity to extend this gesture space is to investigate additional descriptors of bend gestures without introducing new locations. In this context, size and angle are the two common additional descriptors of bend gestures. In this work, we conducted two (preliminary and main) studies to investigate BLV and sighted users' performance and preference for multiple magnitude levels of size and angle of bend on a smartphone-sized deformable prototype. Finally, we discuss the results and propose user group-specific design recommendations.