Tactile Glance: Encoding Notifications using Illusive Movement Constraints for Eyes- and Ears-free Interaction

Voice-over features enable visually impaired users to access information and communicate with others using their mobile devices. However, these features rely heavily on audio feedback and create challenges for users in scenarios where they cannot hear the feedback. This thesis presents a haptic interaction technique that enables tactile glancing by utilizing tangential movement haptic illusion with tactile marks along the movement path, providing an overview of the notifications. The illusion was created by rendering friction-induced grain vibrations caused by the frictional movement of an object. This technique can encode notification information to a tactile channel using illusive movement parameters, including maximum travel distance and tactile marks along the travel path. The user can examine the movement to recognize the notification types and counts without wearing headphones and decide to put them on if the notifications seem to be of interest. We conducted a direction discrimination, a two-mark discrimination, and a haptic mark counting study to observe how people exert tangential force directionally and estimate the average maximum force magnitude exerted. Through the user study, we gained insights into how many directions and tactile marks are feasible for notification encodings and how to space those marks apart to achieve higher interpretation accuracy.