Impact of Change Blindness on Worker Hazard Identification at Jobsites

Due to the dynamic nature of construction sites, workers face constant changes, including changes that endanger their safety. Failing to notice significant changes to visual scenes - known as change blindness - can potentially put construction workers into harm's way. Hence, understanding the inability or failure to detect change is critical to improving worker safety. No study to date, however, has empirically examined change blindness in relation to construction safety. To address this critical knowledge gap, this study examined the effects of change types (safety-relevant or safety-irrelevant) and work experience on hazard-identification performance, with a focus on fall-related hazards. The experiment required participants (construction workers, students with experience, and students with no work experience) to detect changes between two construction scenario images that alternated repeatedly and then identify any changes. The results demonstrated that, generally, safety-relevant changes were detected significantly faster than safety-irrelevant changes, with certain types of fall hazards (e.g., unprotected edge hazards) being detected faster than other types (e.g., ladder hazards). The study also found that more experienced subjects (i.e., workers) achieved higher accuracy in detecting relevant changes, but their mean response time was significantly longer than that of students with and without experience. Collectively, these findings indicated that change blindness may influence changes in workers' situation awareness on jobsites. Demonstrating workers' susceptibility to change blindness can help raise awareness during worker trainings about how workers allocate and maintain attention.