Three visual search experiments evaluated the benefits and distracting effects of using luminance and flashing to highlight subclasses of symbols coded by shape and color. The details are given of the study and of the experiments. In each of the experiments, the search times for nonhighlighted target subclasses were not affected by the presence of brighter and flashing targets. The failure of the initial experiment to find a significant performance improvement caused by increasing the symbol luminance suggested that a larger luminance increase was necessary for this code to be effective. The overall results suggest that using luminance and flashing to highlight subclasses of color- and shape-coded symbols can reduce search times for these subclasses without producing a distraction effect by way of a concomitant increase in the seach times for unhighlighted symbols.
Abstract