Mapping the Global South: Equal-Area Projections for Choropleth Maps
This addresses the lack of clear criteria for selecting map projections in visualization research, though it is incremental as it focuses on a specific domain.
The study investigated how social scientists choose equal-area projections for choropleth maps of the Global South, finding that projection was the most important design choice and the Equal Earth projection was most commonly used.
Choropleth maps are among the most common visualization techniques used to present geographical data. These maps require an equal-area projection but there are no clear criteria for selecting one. We collaborated with 20 social scientists researching on the Global South, interested in using choropleth maps, to investigate their design choices according to their research tasks. We asked them to design world choropleth maps through a survey, and analyzed their answers both qualitatively and quantitatively. The results suggest that the design choices of map projection, center, scale, and color scheme, were influenced by their personal research goals and the tasks. The projection was considered the most important choice and the Equal Earth projection was the most common projection used. Our study takes the first substantial step in investigating projection choices for world choropleth maps in applied visualization research.