On the Benefits and Drawbacks of Radial Diagrams

Book Chapter pdf-Version (later)

Cartesian and Radial Treemap (Bubblemap)

In this book chapter we discuss the differences and commonalities of radial and Cartesian visualizations. Though radial diagrams are oftentimes not seen as efficient representations of data they sometimes do a good job. They are not as space-efficient as Cartesian visualizations but in many cases they benefit from aesthetics. In some scenarios they are also very powerful when there are no explicit end points on a data axis. A circular shape can be used to close this gap by putting formerly existing end points in a Cartesian representation together. Also for visually encoding circular or periodic time radial diagrams are a good design, sometimes also extended to spiral representations meaning several circles radially stacked on eachother with some increasing radius depending on the period.

Typically, pie charts are regarded as a bad design as explained by some researchers in the field. A pie chart mumbles when it speaks, as coined by Stephen Few. The drawback is the poor comparability of quantitative data values due to the non-aligned scales.