# Improving Human Ground Control Performance in Unmanned Aerial Systems
## 2 State of the Art
### Shared Displays and Team Performance  
[PERSON] suggests that SA directly affects performance, particularly poor SA leads to poor performance [8]. This idea is implicitly and explicitly supported throughout theliterature and applies to both teams and people. For example, [PERSON] et al. found a positive correlation between TSA and team performance [17]. [PERSON] also proposes that the interface design (especially the displays) will influence the SA by determining the amount and accuracy of the information that can be acquired. Fewer articles focus on the impact of displays on SA, while the majority comment more on training [9; 10]. However, there have been some. Of these, there are three empirical studies linking display sharing to team performance through the influence of TSA. Unfortunately, the conclusions of such experiments are ambiguous both for the pattern of results and for the disorders within the experimental design. These studies will be briefly reviewed to place this study in the context of existing work and to demonstrate the need for further experimentation to clarify the relationship between shared displays and team performance. Sebok used high-fidelity nuclear power plant simulations to compare teams of nuclear power plant operators using conventional or advanced interfaces [16]. Advanced interfaces were designed to improve TSA (along with other factors) and it was found that performance improved when they were used compared to conventional interfaces. However, it is not possible to say which feature of the interfaces caused this improvement. The advanced interfaces provided integrated information and a common overview of the system (shared display), while conventional interfaces did not. Therefore, they confused the advantages of an ecological display [18] with the presentation of all the information to all team members. The latter manipulation was intended to increase TSA, but due to the confusion, it is unclear whether it was actually influential. Measures of improvements in TSA with the advanced interface interacted with the size of the crew, further confusing the interpretation of the results. The study also looked at the effect of various defects that occur in the plant. They showed that the failures caused a temporary decrease in TSA, but did not investigate the reverse, i.e., does TSA improve fault response? Still in [16], the author highlights the relevance for survey drone fleet management applications on shared displays as a means of improving TSA and demonstrates the importance of comparing routine performance with that in case of off-nominal situations. Therefore, both these factors have been manipulated in the experiment we present in this paper, and simulations have been designed accordingly. Shared displays and TSA were explicitly examined in [11] using a task that required two-person teams to defend a departure base from arriving planes. One team member was responsible for classifying the aircraft (e.g., friend or foe) and the other was responsible for appropriate action (e.g., destroying them). The TSA was manipulated by allowing both team members to see each other's displays (good TSA) or by allowing them to see only their own displays (poor TSA). Unfortunately, the results of this manipulation were unclear. Performance only deteriorated in the conditions of the non-shared display when it was completed before the shared condition without any training on the role of the other team members. In all other counterbalanced presentation performance orders, it was equivalent. This model of results suggests that the difference in performance arose from a lack of understanding of the task because so little information was presented about it (there was no practical evidence) rather than the manipulation of the TSA. Therefore, no definitive conclusions can be drawn from this study about the effects of TSA on team performance. Further work should include training to ensure that the results are due to the displays themselves, not the lack of training.