Task-Based Effectiveness of Interactive Contiguous Area Cartograms

Cartograms are map-based data visualizations in which the area of each map region is proportional to an associated numeric value (e.g., population or gross domestic product). A cartogram called contiguous if it conforms this principle while also keeping neighboring regions connected. Because their distorted appearance, cartograms have been criticized as difficult read. Some authors suggested that may be more legible they accompanied by interactive features animations, linked brushing, infotips). We conducted experiment evaluate claim. Participants had perform visual analysis tasks with and noninteractive cartograms. The task types covered various aspects readability, ranging from elementary lookup synoptic (i.e., participants summarize high-level differences between two cartograms). Elementary were carried out equally well without interactivity. Synoptic tasks, contrast, features. With access interactivity, however, most answered even questions correctly. In a subsequent survey, rated "easy use" "helpful." Our study suggests interactivity has potential make accessible for those readers who unfamiliar computer graphics do not prior affinity working maps. Among features, animations strongest positive effect, so we recommend them minimum when displayed on screen.