USER-CENTERED INTERFACE DESIGN OF TACTICAL AIRCRAFT DISPLAYS

Tactical aviators must perform under highly complex, dynamic, multitask decisionmaking situations. At any point in time a number of different tasks may demand attention, and each of these tasks is typically knowledge intensive and procedurally complex. Contact identification alone often involves time-compressed, ambiguous decision problems. The memory and cognitive processing requirements of these tasks often exceed the human's capacity to perform the requisite subtasks. A user-centered design approach was taken with deference to human performance capacities and limitations. Design features include the use of graphics to support intuitive processes and reduce cognitive processing requirements and structuring and presenting information in a format that parallels the decisionmaker's natural cognitive strategies. These decision support display features aredirected at improving information sampling, reducing processing complexity, making information conform to human memory and cognitive strategy characteristics, avoiding cognitive overload, and enhancing the speed, coherence and efficiency with which decisionmakers are able to shift attention and thought between the various tasks that arise. Topics include a discussion of decision support and human-system interaction principles and examples of modules designed to enhance decisionmaking. INTRODUCTION Tactical air warfare spans a broad class of actual scenarios, including both offensive and defensive operations for land and sea-based assets. In spite of the differences in mission, tactics and weaponry inherent in these different scenarios, however, the need for automated decision support technology to assist the decisionmaker when time is short, when contacts are numerous, and when the situation is both fluid and ambiguous is growing for all such operations. Furthermore, the principles underlying this decision support technology are much more unified than the disparate missions would suggest. All involve high cognitive workloads, short decision times, and potentially catastrophic consequences for bad decisions. In recognition of the complex and difficult decisions required in these types of situations the Tactical Decision Making Under Stress (TADMUS) program was initiated to conduct research in the areas of human factors and training technology. The TADMUS program is being conducted to apply recent developments in decision theory and humansystem interaction technology to the design of a decision support system for enhancing tactical decisionmaking under the highly complex conditions involved in antiair warfare scenarios in close to land environments. The goal is to present decision support information in a format that minimizes any mismatches between the cognitive characteristics of the human decisionmaker and the design and response characteristics of the decision support system. This paper presents these underlying decision support principles and discusses their use in the design of decision support systems (DSS) for enhanced tactical air situation awareness in airborne, land and sea-based systems. Much of the technical data presented below was developed in conjunction with a DSS specifically designed for implementation aboard Aegis cruisers to assist decisionmakers in the combat information center (CIC) in responding to antiair scenarios. Although not designed for airborne missions, such a DSS is directly applicable to the type of missions flown by airborne warning and control system (AWACS) aircraft, (as well as other aircraft) and indeed a fielded system might have prevented the tragic mistake in Iraq when a U.S. AWACS aircraft vectored two fighters to shoot down hostile helicopters that eventually proved to be U.S. Army helicopters carrying U.S. and foreign dignitaries. In jumping from decisionmaking in the team environment characteristic of an Aegis CIC or an AWACS aircraft to the lonelier confines of a fighter or bomber cockpit, the main difference in terms of the principles underlying a DSS is that there is no longer ambiguity and error created in the. communication process between the team members and the decisionmaker. Other factors, such as multiple and ambiguous contacts, high task loads on the individual, short decision time frames, ambiguous and erroneous information from off-board sources, and time-critical responses, are similar across all aspects of tactical air operations. A discussion of the common underlying principles in decision support will comprise the remainder of this section.