Visual Organization and Thematic Map Communication∗

ABSTRACT Total map perception integrates geographic material (the base map) and thematic material (the distribution which is mapped). Psychological studies of the figure-ground relationship indicate that maps should be designed so that thematic symbols are experienced as figures, and base map materials as ground. Figure perception is enhanced by heterogeneity, contour, and area or enclosedness; the cartographic designer has greatest control over heterogeneity. Tests of preprinted area patterns for heterogeneity indicate that the perception of figures against ground is most enhanced, other things being equal, by patterns which have coarser texture and a higher percentage of area inked.