Operator Stress and Display Design
These design guidelines, based on knowledge of how operators perform under time and task pressure, can lead to better decision making in emergencies. IT IS NEAR THE END OF A LONG SHIFT, some hours past midnight, and the combined effects of caffeine, nicotine, and sugared snacks are no longer sufficient to sustain the alertness of tired and weary operators. Circadian rhythms are at their lowest ebb while oppressive, routine operations have so long persisted that chronic boredom reigns supreme. Suddenly a warning sounds, then another, then another — the systems displays are producing a cascade of flashing lights and tone alarms. Operators rush to workstations, where information begins to overflow like a virtual Niagara of bytes. The apprehension in the air is tangible. It is evident to everyone that a coherent response must be made soon if the situation is to be recovered. As a result, time pressure is now added to anxiety and information overload and rapidly shifts the situation from boredom to terror (Hancock, 1997a). The answers to the problem are somewhere in the system, but a massive noise-to-signal problem is building by the minute. Unfortunately, the resolution is spread across a tapestry of displays. Like pieces of a dynamic jigsaw puzzle, the solution resides in separate parts distributed across many minds, but team communication and team cohesion are rapidly failing, overwhelmed by the demands of information overload and the destructive effects of situational stress. If someone doesn't do something soon…