This article reports on a study of dynamic hazard warnings which are sensor-based signaling systems that alert the user about a potential hazard that may require an intervention or closer monitoring. The author uses the example of a simplified cockpit warning system that alerts the pilot regarding ice in the carburetor, a condition that can cause engine failure. The normative aspects of responses to warnings are analyzed, and a distinction is made between two forms of responses to a warning system (compliance and reliance). The author classifies the determinants of responses to warnings as normative, task, and operator factors. The author also reviews the current literature in the areas of warnings and automation. The author concludes that warning systems can have complex effects on behavior. In addition, warnings are usually parts of complex systems, and users are in most cases engaged in some ongoing activity when encountering them. Thus it is necessary to consider the warning system within the context of a broad task analysis that includes information sources, priorities, and constraints.
Abstract