Blind people interacting with large touch surfaces:Strategies for one-handed and two-handed exploration

Interaction with large touch surfaces is still a relatively infant domain, particularly when looking at the accessibility solutions offered to blind users. Their smaller mobile counterparts are shipped with built-in accessibility features, enabling non-visual exploration of linearized screen content. However, it is unknown how well these solutions perform in large interactive surfaces that use more complex spatial content layouts. We report on a user study with 14 blind participants performing common touchscreen interactions using one and two-hand exploration. We investigate the exploration strategies applied by blind users when interacting with a tabletop. We identified six basic strategies that were commonly adopted and should be considered in future designs. We finish with implications for the design of accessible large touch interfaces.