From tactile to virtual: using a smartwatch to improve spatial map exploration for visually impaired users

Tactile raised-line maps are paper maps widely used by visually impaired people. We designed a mobile technique, based on hand tracking and a smartwatch, in order to leverage pervasive access to virtual maps. We use the smartwatch to render localized text-to-speech and vibratory feedback during hand exploration, but also to provide filtering functions activated by swipe gestures. We conducted a first study to compare the usability of a raised-line map with three virtual maps (plain, with filter, with filter and grid). The results show that virtual maps are usable, and that adding a filter, or a filter and a grid, significantly speeds up data exploration and selection. The results of a following case study showed that visually impaired users were able to achieve a complex task with the device, i.e. finding spatial correlations between two sets of data.