Johnny Holland have written another insightful article, this time on the Design of Alarms & Alerts.
Alerts are used to give the user feedback about important events that need attention for some reason.This may mean errors, failures, breakdowns, or important changes that need action–or interaction. The term “alert” is used here to include different types of significant event feedback in order of criticalityMikkel Michelsen
The article covers some fundamental interaction design principles such as matching criticality to obtrusiveness, and considering:
- Size and placement determine visibility.
- Colors signal criticality. Using red sparingly for high criticality alerts and to raise obtrusiveness.
- Static or dynamic. The eye catches movement, therefore raise obtrusiveness with animation and movement.
- Sound/voice. Sound is crucial. If the user is not looking at your display device, they will not notice the alert. This is why most alerts are also audible.
- Repetition: Repeat an alert if needed.
- Permanence: Consider the case of missed alerts. By increasing the amount of time the alert is displayed, obtrusiveness can be increased.
Related links:
- The Spotlight and Brighten design patterns at the Yahoo Design Pattern library.
- Interaction Design & Prototyping on the Nokia Design Forums.
- A 1999 paper by R. W. Obermayer on Human-Computer Interaction for Alert Warning and Attention Allocation Systems for Multi-Modal stations
- A 1998 paper by Dr Anne Bruseberg and Prof Peter Johnson from the Department of Computer Science, University of Bath Bath, UK – Understanding Human Error in Context