Designing for Stress
Christopher D. Wickens University of Illinois at Urbana-Champaign
The proposal must be postmarked no later than 5 p.m., but as the copying is being done frantically an hour before the deadline, the machine ceases to function, displaying a series of confusing error messages on its computer-driven display. With panic gripping the unfortunate victim, he finds himself unable to decipher the complex and confusing instructions. Meanwhile, in another building on campus, the job candidate giving a talk has fielded a few difficult (some might say nasty) questions, and now turns to the video demo that should answer the questions. Nervous and already upset, she now finds that the VCR will not function, and as she fiddles with the various buttons, no one lifts a hand to assist her. Finally, in the sky above the city, the pilot of the advanced commercial airliner is descending toward a landing, having programmed the flight management system to proceed according to ATC clearances. Suddenly, the message arrives from ATC that the plane has dangerously descended in conflict with another airline. The system must be reprogrammed to an alternative heading and level.
Difficulties in a human-system interface, like those described here, characterizing stressful performance with a complex system, are typically addressed by three generic means: training, selection, and design ( Huey & Wickens, 1993). Design issues themselves may be categorized into those that focus on task design, (e.g., workload reduction through task sharing) and on interface design. Many of the chapters in this book have discussed training issues, whereas Hogan and Lesser (chap. 6, this volume) have considered the implications for selection. In the present chapter we consider the implications for design.
It is obvious that design changes, intended to lessen the unfortunate consequences of stress on human-system performance, must be based on an accurate