Influencing the Perception of Contour Lines

Abstract

Two possible causes of the failure of map users to successfully interpret relief forms from contour maps are Gibson's texture gradient effect which may give false depth cues; and, the expectancy or prior set developed from previous experience by the map reader. In the two experiments reported attempts were made to alter subjects' expectancy by providing cues or contextural information related to the task of interpreting a number of unquantified contour patterns. Although expectancy has proved to be a dominant influence on contour interpretation, successful priming in the experiments provided subjects with a number of conflicting but valid hypotheses which were often resolved in the direction of the texture gradient.