The Indispensable Guide to Chart Design and Data Visualization, Part 2

In part one of this series, we looked at chart design and specifically why, when and how to use certain charts over others. The cheat sheet offered a number of categorical comparisons and many insights into how to most effectively display values in order to produce actionable analytics for your organization.

However, displaying data becomes significantly more complex than the tips in the cheat sheet cover when there's a need to show extra dimensions of information within the same visualization. It's not always X and Y; sometimes Z joins the party as well.

Take the example below showing Olympic gold medals for the top 10 countries in 2008. A bar chart was a good choice here because it allows easy comparison and horizontal bars signal that there's a ranking.

They're not all that easy, though. Many new chart types need to be employed in order to adequately convey the depth that some analytics require.

As such, the descriptions below provide a few techniques for extending your visualizations with additional dimensions of data. Not only do they delineate chart types, but also examples of when to use them.

Technique #1: Stacked bars

 

Summary: Use when the extra dimension (bar segments) values contribute to a whole (total bar size). Also, the sum of the parts should be more important than comparing between them over different categories.

The good: 

Good ...