A Design Problem

I borrowed this example from a wonderful webcast by Howard A. Spielman Ph.D., which he did for DCI. He very consciously used it as an example of poor data presentation, specifically to illustrate the problems associated with tilting data graphics. This image was originally published in the book Visualization: Using Computer Graphics to Explore Data and Present Information, Judith R. Brown, et. al., John Wiley & Sons, 1995.

[Scroll down to see our solution to this graph's design problems.]
Design Example #7 Problem

My Analysis

This is a great example of two common problems:

  • Choosing the wrong type of graph.
  • Formatting the graph in a manner that obscures the data, in this case by tilting the pie charts to the left.

A Solution

I could have used a stacked bar graph with a separate bar for each year and a separate section of each bar for each country, which would have worked fine, but I felt that a series of bar graphs—one for each country—offered some advantages.

Design Example #7 Solution
[Click graph to enlarge]

This design allowed us to clearly display the trend of car sales across time for each country individually, while also making comparisons between the countries easy.