Abstract
Children and even some adults struggle to understand and use maps. In the symbolic realm, users must appreciate that the marks on a surface stand for environments and must understand how to interpret individual symbols. In the spatial realm, users must understand how representational space is used to depict environmental space. To do so, they must understand the consequences of cartographic decisions about the map's viewing distance, viewing angle, viewing azimuth, and geometric projection. Research identifies age-linked progressions in symbolic and spatial map understanding that are linked to normative representational and spatial development, and reveals striking individual differences. Current work focuses on identifying experiences associated with better map understanding. New technologies for acquiring, manipulating, analyzing, and displaying geo-referenced data challenge users and researchers alike.