4.1.2. Generalised Results

From analysis of the above graph for the different participants, some general conclusions can be drawn about the relationship between the assessed workload values and the identified ATC events.


particularly remarkable in conflict resolution processes. Some participants implement actions to resolve the conflict that are successful on the first attempt. On the contrary, other participants must implement several conflict resolution strategies if the first attempt is not satisfactory. For this reason, depending on where the participant is in the decision-making process when the workload assessment question is asked, the recorded values may vary.

The results presented in this study were obtained with a small sample of participants. Therefore, caution should be exercised when extrapolating these conclusions to all air traffic controllers or potential participants in the simulations. In the case under study, this sample of participants has been used to define the methodology and these steps are applicable to other subjects, although the results obtained by introducing more participants may vary. Therefore, these first participants are considered a validation group for the methodology to be followed. In future stages of research, a larger number of participants will be included in the study.

Another limitation is the use of ATCO students instead of air traffic controllers with operational experience. Future work in this research line aims to overcome this limitation. These ATCO students have been involved so as to obtain a methodology that is as robust as possible. In later stages, in-service ATCOs will be included as participants.

These limitations are common to other studies conducted in the study of human factors associated with air traffic controllers. The authors of [32] focused on assessing the effects of the number of crossings, traffic flows, and aircraft separation on the mental workload and perceived emotion of ATCOs. One of the limitations identified in the study was the caution necessary in interpreting the results, as only two ATCOs were included as participants.

Another study in which the number of participants is considered a limitation is [33]. In this case, the aim of the study was to monitor the heart rate variability of the controllers and to determine the suitability of the methods used. To overcome this limitation, including a larger number of participants in the study is suggested. However, the results obtained with the study sample are considered beneficial, as they provide an indication of the suitability of the analysis methods used in this type of research.

In the study documented in [34], the future work reported is very much in line with that proposed in this line of research. In their study, evaluating the behavioural response in ATCOs in terms of the use of the procedural control bay and the electric flight strip bay using human-in-the-loop simulations was proposed. Two experts and two trained subjects were used as participants. Future work includes the development of a study with a larger number of participants, as well as on-site replication in a real operational scenario.

Another possible solution to help overcome the limitation of all participants being ATCO students is to consider a mixed group where some participants have previous experience as ATCOs. As an example, this logic is applied in [17]. In this study, the objective was to present the development and evaluation of a 3D space-based metric solution for air traffic control workload. Participants were part of two different expertise groups: four were retired ATCOs and the other six were researchers in the ATM domain or participants who had completed an ATC course. The study presents comparative results between the two groups of participants.
