Visualizing Sets with Linear Diagrams.

This paper presents the first design principles that optimize the visualization of sets using linear diagrams.These principles are justified through empirical studies that evaluate the impact of graphical features on taskperformance. Linear diagrams represent sets using straight line segments, with line overlaps correspondingto set intersections. This study builds on recent empirical research, which establishes that linear diagramscan be superior to prominent set visualization techniques, namely Euler and Venn diagrams. We addressthe problem of how to best visualize overlapping sets using linear diagrams. To solve the problem, weinvestigate which graphical features of linear diagrams significantly impact user task performance. Tothis end, we conducted seven crowdsourced empirical studies involving a total of 1,760 participants. Thesestudies allowed us to identify the following design principles, which significantly aid task performance: usea minimal number of line segments, use guidelines where overlaps start and end, and draw lines that arethin as opposed to thick bars. We also evaluated the following graphical properties that did not significantlyimpact task performance: color, orientation, and set order. The results are brought to life through a freelyavailable software implementation that automatically draws linear diagrams with user-controlled graphicalchoices. An important consequence of our research is that users are now able to create effective visualizationsof sets automatically, thus improving human–computer interaction