# Situational Awareness Assessment of Drivers Boosted by Eye-Tracking Metrics: A Literature Review
## 4 Discussion
Common themes associated with eye-tracking studies include automated driving, driver behavior, driving simulation, and SA. Most studies are concentrated on transportation research and human factors, with a higher concentration in countries such as the Netherlands, the USA, and China. This concentration provides an opportunity to delve into further research investigations from regions of the Americas. Regarding the demographic study within the compiled body of studies, a noteworthy trend was observed in the significant involvement of male participants, with a maximum of 1% being female. This gender imbalance could be a limitation and bias when generalizing outcomes predominantly from male samples. Moreover, the average age of participants is around 27 years, a factor that needs consideration in studies of assessment of SA requiring analysis of novice versus expert populations. Furthermore, only 12.1% of studies on the assessment of SA with eye-tracking measures were conducted in real environments with industrial vehicles, presenting an opportunity for future research, such as studying industrial vehicle operators like forklift drivers. Likewise, the results suggest a need for more effort in conducting research in real-world environments for optimal validation of study variables. Although this approach may incur higher costs and require more extensive investment in ethical, safety, and data collection protocols, the advantages are notable. Similarly, the review uncovered the need for future research focused on the industrial environment, as such studies are scarce. Likewise, concerning the measurement equipment and software used, Tobii Pro Lab, Lab version 1.232 and Tobii Pro X2-60 glasses (discontinued) were the preferred eye trackers, as reported in the majority of experiments. It is essential to note that some eye trackersmay generate interference with operator equipment, and frequencies greater than 50 Hz are preferable. Additionally, in real environments, the use of wireless equipment may encounter interference due to the company's infrastructure, potentially leading to signal loss and data loss. It is also crucial to consider the presence of natural light in the data collection space, as sunlight could interfere with data collection. Moreover, in experiment design, demographic and cultural characteristics should be considered due to differences in pupil color [31]. Concerning the review process, the results demand a discussion regarding criteria such as validity and reliability. In terms of viability, this review presents outcomes similar to those found in existing reviews, for instance, by [21; 41], particularly in terms of the relationships observed between physiological metrics measured with eye tracking and the assessment of SA. Finally, regarding reliability, this review presents a systematic methodology that allowed us to compile demographic, statistical, and experimental design data, showing that the information collection remains consistent. However, further studies are necessary to identify variations across different study domains, distinct from those related to driving.