A theory of structured visual search and target luminance, with applications to some industrial inspection tasks

Abstract

The importance of target luminance in evaluating tho relative efficiency of structured versus unstructured search in a large and visually homogeneous field is discussed.

Differences in detection times appear to be due to the apparent luminance of the target. Detection is a result of a trade-off between the physical luminance of the target and the degree of spatial uncertainty associated with a particular search pattern. In a structured visual field, with a systematic search pattern, the spatial uncertainty of the target is conceived as being lower than with an unstructured field and search pattern.

Evidence from studies on visual search and on the effect of spatial uncertainty on visual performance are presented. Some of the industrial implications of the theory, particularly in the field of inspection, are also described.