Where to Locate Wearable Displays? Reaction Time Performance of Visual Alerts from Tip to Toe

Electronics continue to reduce in size and cost, offering tremendous potential to bring the power of computation to a wider audience and to more aspects of our lives. Computers that once used to fill a room are now mobile, and soon might even be incorporated into our clothing. This notion of wearable computing promises a highly integrated and personal information and communication infrastructure that travels with us. However, unlike traditional computing systems, wearable devices do not require explicit periods of user attention – a user does not sit down in front of wearable devices like they would with a traditional computer. Instead, the strength of wearable computing lies in its lightweight and spontaneous interaction.

Wearable computers will be able to notify users about, for example, new emails, upcoming meetings, changes in weather forecast, stock market fluctuations, excessive caloric intake, and other aspects of our lives they will be able to monitor directly or have access to. Finding ways to usefully and reliably deliver this information, while still balancing the costs of attention demand and distraction, will be important to consider if the technology is to be successful.

One way to draw a wearer’s attention is through vibrotactile stimulation, commonly employed in mobile devices to alert users (e.g., to an incoming call). Also popular, although not tied to any particular body location, are audio alerts. Visual displays offer an alternative notification method. However, there has been little research into their optimal body placement, despite being an unobtrusive, lightweight, and low-powered information delivery mechanism. Furthermore, visual stimuli have the added benefit of being able to work alone or in concert with conventional methods, including auditory and vibrotactile alerts.

We believe the results presented in our paper allows developers and researchers to best align their application with areas of the body that have the necessary attention demand and reaction time characteristics. Systems that apply this knowledge may be less disruptive and reduce overall information burden.



Harrison, C., Lim, B. Y., Shick, A., and Hudson, S. E. 2009. Where to Locate Wearable Displays? Reaction Time Performance of Visual Alerts from Tip to Toe. In Proceedings of the 27th Annual SIGCHI Conference on Human Factors in Computing Systems. CHI '09. ACM, New York, NY. 941-944.

© Chris Harrison