Objective: We examined the effects of spatial uncertainty, field dependence/independence (FD/I), and sex on vigilance performance and perceived workload in elementary school children.
Background: Building on previous work in which children demonstrated their ability to evaluate workload, we tested whether spatial-uncertainty manipulations in a vigilance task would elicit in children the same deleterious effects on performance and workload as it does with adults. We also examined individual difference effects associated with FD/I and sex to determine their influence on both performance and workload.
Method: In the low-uncertainty task, stimuli appeared in the center of the computer screen; in the high-uncertainty task, they appeared in one of the four quadrants of the screen. Neutral events consisted of uppercase letter strings. Critical signals consisted of a single lowercase letter among uppercase letters. Following each vigil, children completed a workload assessment via a modified version of the NASA Task Load Index.
Results: Children showed lower perceptual sensitivity, greater response latency variability (RTSD), and a higher response criterion in the uncertain display condition. Workload scores reflected these performance differences. Field-dependent children showed lower perceptual sensitivity and greater RTSD than did field-independent children. The two groups exhibited differing workload profiles. Despite no objective performance differences, boys reported greater workload than girls.
Conclusion: The scale demonstrated sensitivity and diagnosticity with regard to both the task variable and individual differences.
Application: These findings contribute to the emerging field of "educational ergonomics" and indicate that appropriate assessment tools might identify children who are experiencing increased workload.
Keywords: NASA Task Load Index; educational ergonomics; sustained attention; vigilance; workload.