An evaluation of blink inspection

It has been suggested that performance in an industrial inspection task can be improved by rapidly alternating images of the item to be inspected and a perfect item onto the visual field of the inspector. Such a blink inspection system was evaluated for a complex item (a printed circuit board which could contain three flaws) and a simple item (a blank field which could contain one flaw) using eight student subjects for each of five inspection conditions. Three groups, one using blink inspection and two control groups, inspected circuit boards; two groups (one blink and one control) inspected blank fields. Search time was improved by blink inspection for the circuit boards and with different defects showing different degrees of improvement. Only one type of defect showed both reduced search times and reduced errors. For blank fields, performance was worse under blink inspection. Subjects showed a consistent tendency to terminate their search for defects in a logical manner, with stopping time related to search difficulty. Measures of heart rate mean and variability were taken as a pilot study to measure task stress. There was little evidence from the heart rate measures that the task was stressful.