Allen W. Dukes

Use of the RoboFlag synthetic task environment to investigate workload and stress responses in UAV operation

Use of unmanned aerial vehicles (UAVs) is an increasingly important element of military missions. However, controlling UAVs may impose high stress and workload on the operator. This study evaluated the use of the RoboFlag simulated environment as a means for profiling multiple dimensions of stress and workload response to a task requiring control of multiple vehicles (robots). It tested the effects of two workload manipulations, environmental uncertainty (i.e., UAV’s visual view area) and maneuverability, in 64 participants. The findings confirmed that the task produced substantial workload and elevated distress. Dissociations between the stress and performance effects of the manipulations confirmed the utility of a multivariate approach to assessment. Contrary to expectations, distress and some aspects of workload were highest in the low-uncertainty condition, suggesting that overload of information may be an issue for UAV interface designers. The strengths and limitations of RoboFlag as a methodology for investigating stress and workload responses are discussed.

Collaboration technologies improve performance and communication in air battle management.

Team communication is critical for Air Battle Management (ABM). In this study, two communication tools (text chat and electronic whiteboard) and two team resource aids (tabular and graphical displays) were introduced during simulated ABM to supplement radio communication. Results showed that combined chat and virtual whiteboard improved team performance, decreased number and duration of radio transmissions, but had mixed effects on workload. In addition, the graphical resource display improved team performance, decreased number and duration of radio transmissions, and reduced workload compared to the tabular display. These findings indicate that collaboration technologies introduced in this experiment may benefit military operations.

Evaluation of Subjective and EEG-Based Measures of Mental Workload

Assessment of mental workload is an important aspect of many human factors and HCI applications. Not surprisingly, a number of workload measures have been proposed. This study examined the sensitivity, convergent and concurrent validity of several subjective self-report and EEG workload measures. Most measures displayed adequate sensitivity to task difficulty manipulations, but relatively modest convergent and concurrent validity. Overall, we believe these result serve to aid human factors practitioners in selecting measures of workload for varied applications.

Assessment of a Novel Chat Messaging Interface for Rapid Communication in Tactical Command and Control

Two experiments explored speed of communication when transmitting and receiving chat messages in different formats for a military command and control (C2) task. In Experiment 1, participants were prompted with a tactical display and responded by composing chat messages with an appropriate command. Speed, accuracy, and subjective workload were compared for three chat messaging formats: 1) full-text; 2) abbreviated text; or 3) click-chat. Writing full-text messages took longer, resulted in more typing errors and higher workload ratings than abbreviated text or click-chat. Although there was no difference in response times between abbreviated and click-chat messaging, the abbreviated chat yielded higher error rates. A translation delay was evidenced by slower initial response times for abbreviations and click-chat compared to full-text. However, faster message completion, once initiated, compensated for this delay resulting in faster communication overall. Experiment 2 demonstrated that there was no difference in the speed, accuracy, or workload for completing commanded actions when receiving abbreviated compared to full-text chat messages

Evaluation of Interface Types in an Adversarial Team Based Environment

The present study addressed the effects of a flexible delegation-type control interface for unmanned vehicles (UVs) on performance in a team-oriented, dynamic, adversarial environment. Thirty-six people served as paid participants in this study. Teams of two participants competed against each other in a RoboFlag simulation based on ‘capture-the-flag.’ Participants controlled their UVs manually, through automated commands, or both (flexible control). Results of the experiment indicated that task performance and subjective workload were adversely affected in the automation-only condition, but no differences were detected between the manual and flexible conditions. Overall, results support previous research using RoboFlag. Performance in the automation condition was insufficient to meet task demands indicating the inappropriateness of UV control limited in this fashion. However, the lack of performance differences observed in this task between the flexible and manual interfaces calls into question when the flexible delegation-type interface may provide a performance benefit.

Influence of Stereoscopic Depth on the Flanker Compatibility Effect

Modern air-traffic control displays feature complex symbology that may negatively impact operator performance efficiency. Manipulations of stereoscopic depth have been proposed as a means to declutter such displays and thereby to enhance operator performance. In this study, we employed a flanker task designed by Eriksen and Eriksen (1974) to further investigate that possibility. Participants were required to correctly respond to target letters from the sets H and K and S and C that were bordered horizontally by response compatible and response incompatible flanking letters. Using a stereoscopic imaging technique, the flanking letters were made to appear .1 and .8 cm in front of or behind the target letters, or on the same plane as the target letters. Consistent with the findings of Eriksen and Eriksen (1974), when all letters appeared on the same plane, response times (RTs) to target letters in the presence of response incompatible flanking letters were significantly elevated in comparison to RTs in the presence of response compatible flanking letters. These effects were eliminated when the flankers appeared to be slightly in front of the target letters or at both distances behind the target letters. However, the flanker effects were restored when the flankers appeared well in front of the target letters. The results suggest that the decluttering ability of stereoscopic depth is complex and dependent on the relative apparent distance between the targets and their bordering flanker elements.

Managing a Supply Chain: What Communication Patterns Might Divulge about Information Availability and Team Performance

Teamwork is continually becoming more diverse and complex, with teams facing distributed and asynchronous collaborative situations. The crux of making these complex situations work successfully is the ability to convey useful information to those who need it when they need it. A fundamental question remains: how much information is enough? Decision makers need a certain level of information to make effective decisions; however, too much information can be overwhelming or even detrimental. The present study uses a modified supply chain simulation to examine the impact of information availability on overall team performance and communication. Information view and communication were manipulated to constrain information availability. The results are discussed in terms of the impact of information availability on overall performance, communication patterns, information entropy, and situation awareness of distributed teams.

Information Availability and Team Performance: A Network-Centric Supply Chain Simulation

Future concepts of operations purport that sophisticated information technology will significantly enhance mission effectiveness through two fundamental aspects: “speed of command” and “self synchronization.” On one hand, unlimited availability of information may serve to enhance the overall awareness of individuals and teams. On the other hand, unrestricted information push may serve to distract, overwhelm, and overload individuals and teams, thereby compromising their situation awareness and decision-making effectiveness. The question remains, how much information is enough? The purpose of this study was to assess the impact of information availability on decision-making by utilizing a four-person supply chain management simulation. View of information and communication were manipulated to constrain information availability. Results indicated better performance for conditions with more information availability, including unrestricted information push. Overall, these results illustrated the importance of capabilities such as anticipation and redundancy, which seem to be vital to collaborative tasks.