  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.
