Publication Date


Document Type


Committee Members

Frank Ciarallo (Committee Member), Raymond Hill (Advisor), Raymond Hill (Committee Chair), Yan Liu (Committee Member), S. Narayanan (Committee Member), Edward Pohl (Committee Member), Dan Voss (Committee Member)

Degree Name

Doctor of Philosophy (PhD)


Real-world scenarios are complex dynamic systems that are often overloaded with information. Effective performance of these dynamic systems depends on the objects in such systems and the relationship among them. The control of many of these systems is semi-automated. Human operators constantly monitor and control these systems, assess the situation and often make decisions under time pressure. However, this supervisory control paradigm in a dual-task environment can be a very challenging task. Existing interface design methodologies and techniques have not delved deeply enough into defining information displays for complex, dynamic, time-critical, dual-task environments with capabilities for rapid task change awareness and task resumption while continuously maintaining situation awareness.

This research focuses on designing user displays with advanced cueing techniques to support performance in complex dynamic dual-task environments. A primary question addressed in this study is whether visualization methods such as status-at-a-glance displays, interruption recovery tools, and course of action planning tools would assist in maintaining situation awareness, resuming tasks quickly, and effectively perform decision making tasks.

The research examines interface design methods to support supervisory awareness in primary and secondary task situations, rapid assimilation when switching to a secondary task, rapid re-assessment upon return to the primary task or secondary task, a course of action solution explorer for successful mission planning/re-planning, and notification systems such as alerts to inform operators about interrupting tasks. This research provides a means to realize an "at-a-glance" decision making environment.

The methodology adopted in this research effort used a three-stage process. In stage one, the effect of interruptions on trust and coordination among team members was studied. For stages two and three, the operator tasks and the interface protocols for accomplishing the tasks were designed based on the operator function model. Visual display components were designed to maintain situation awareness, resume the interrupted task scenario quickly, and plan/re-plan course of action for missions and anticipate system status. Multi-modal alert techniques are designed to notify the operator about the interrupting task scenario. The hypotheses related to each stage and the designed components were empirically evaluated using human participants.

Results showed that providing an user interface with status-at-a-glance display and interruption recovery tool and other task resumption cues assists the user in maintaining situation awareness and gain change awareness quickly. It was also found that course of action solution exploration tool assists users in quickly designing a feasible course of action and also allows users to re-plan the course of action based on requirements. The use of alerts helps to inform users about a secondary task that would need their attention.

A primary contribution from this research is defining a set of user interface design guidelines for use on small screen displays for dual-task supervisory monitoring and control scenarios. Other significant contributions include the design of the status-at-a-glance display, along with the interruption recovery tool, mission planning tool, and the evaluation of alert techniques in such complex, dynamic, time-critical environments.

Page Count


Department or Program

Department of Biomedical, Industrial & Human Factors Engineering

Year Degree Awarded