| Abstract: | This study was designed to show how those proficient at a machining task, where proficiency was gained through both training and past experience, influence the perceived hazard and risk when observing Computer Numerical Control (CNC) machining. The study was also designed to determine whether the impact of the visual and auditory cues can be isolated during diagnosis of the hazard. In a study that included 40 participants, results show that trained observers can perceive more correctly a hazardous condition which is different from what one would predict based on psychophysics. The results also show that trained participants relied strongly on the auditory cues to diagnose the potential hazard and risk correctly whereas the untrained participants who had access to both auditory and visual senses perceived the potential hazard more incorrectly than those trained and more similarly to a traditional Stevens' psychophysical curve. Untrained subjects who had only auditory input had the most difficulty in distinguishing differences in the perception of hazard. This is important considering recent dialogue about whether there is a need to train for tasks that will be automated. The idea of training, especially for automated tasks, is important in allowing better recognition of hazard and risk in unusual circumstances. Additional research may help to improve the diagnosis of hazard and risk and may enable generalization of the results to other training scenarios in the manufacturing and services industries. |
