CRASINS: an improved method for urgency scaling within and across modalities

Technological advances allow presentation of more information (e.g. alerts, warnings) than operators can process. Effective management of this information requires designing displays and warnings that scale the perceived urgency of the signal to the hazard level it represents. We reviewed existing methods of scaling and propose that determining a user-defined range of acceptable intensities prior to implementing the scaling (the CRASINS method) is most effective. Here, we used the CRASINS method to develop urgency and annoyance scales for visual, auditory, and tactile signals. Parameters examined included interpulse interval (IPI) and pulse duration in the auditory and tactile modalities as well as frequency for auditory and colour for visual stimuli. The greatest range of urgency was obtained with the auditory modality, while visual stimuli result in the lowest levels of annoyance. Manipulations of IPI yielded good utility in all modalities with the highest utility being observed for changes in colour.