Evaluating wrist-based haptic feedback for non-visual target finding and path tracing on a 2D surface

Precisely guiding a blind person's hand can be useful for a range of applications from tracing printed text to learning and understanding shapes and gestures. In this paper, we evaluate wrist-worn haptics as a directional hand guide. We implemented and evaluated the following haptic wristband variations: (1) four versus eight vibromotor designs; (2) vibration from only a single motor at a time versus from two adjacent motors using interpolation. To evaluate our designs, we conducted two studies: Study 1 (N=13, 2 blind) showed that participants could non-visually find targets and trace paths more quickly and accurately with single-motor feedback than with interpolated feedback, particularly when only four motors were used. Study 2 (N=14 blind or visually impaired participants) found that single-motor feedback with four motors was faster, more accurate, and most preferred compared to similar feedback with eight motors. We derive implications for the design of wrist-worn directional haptic feedback and discuss future work.