Perceived Urgency of Tactile Warnings

Tactile warning systems present a viable alternative when the visual and auditory modalities encounter information overload. We modified the Patterson four-step design approach for auditory warning design, adapting it to tactile warning design. Using these approaches for a tactile warning design, we identified key design parameters, which could influence the perceived urgency of tactile warnings, namely spatial location and the number of activated vibrotactors. Using a tactile grid we developed a set of tactile designs varying in activation type, layout, and activation level. The different vibrotactor designs were evaluated using the perceived urgency scale. The results showed that the number of activated vibrotactors was a key design parameter influencing the perception of urgency. This study showed that perceived urgency is a concept that can be applied to tactile warnings and that tactile warnings can be systematically designed to convey appropriate levels of perceived urgency.