
For the last several years, I’ve wondered about what we actually know from scientific studies about how humans perceive graphics. I’ve collected things here and there, but when I started to get into the thick of it, I realized how extensive this body of research really is. There is a lot that I’m leaving out.
Siegrist (17) finds that among bar charts, 2d is not superior to 3d, but 3d charts take slightly longer to process. With pies, 2d is better, and the perspective angle makes a big difference in how accurately the slices are evaluated, most likely because some of the slices are more obscured than others.
Gattis and Holyoak (15) designed an experiment where slope could indicate height, or altitude but that meant that the independent and dependent variables were on the wrong axis. They presented both the right and wrong chart to participants and asked if the dotted line indicate…