How in the World Did We Ever Get into That Mode? Mode Error and Awareness in Supervisory Control

New technology is flexible in the sense that it provides practitioners with a large number of functions and options for carrying out a given task under different circumstances. However, this flexibility has a price. Because the human supervisor must select the mode best suited to a particular situation, he or she must know more than before about system operations and the operation of the system as well as satisfy new monitoring and attentional demands to track which mode the automation is in and what it is doing to manage the underlying processes. When designers proliferate modes without supporting these new cognitive demands, new mode-related error forms and failure paths can result. Mode error has been discussed in human-computer interaction for some time; however, the increased capabilities and the high level of autonomy of new automated systems appear to have created new types of mode-related problems. We explore these new aspects based on results from our own and related studies of human-automation interaction. In particular, we draw on empirical data from a series of studies of pilot-automation interaction in commercial glass cockpit aircraft to illustrate the nature, circumstances, and potential consequences of mode awareness problems in supervisory control of automated resources. The result is an expanded view of mode error that takes into account the new demands imposed by more automated systems.