Wednesday, June 18, 2008

Cognitive dissonance with graphs

This is from the Wall Street Journal blog, who has more money for copyeditors than I do. Leaving aside my distaste for pie graphs, take a look at what's wrong with this graph.

Because this is such a major issue, you would think that someone would catch this mistake before production?

But, in the spirit of Junk Charts, I'll offer the way I think this should look. I think the insured/uninsured/underinsured lines need to be plotted over time on a single line graph to support the author's point, which is that the underinsured population has grown over time.

PS. The original report is here. All of the supporting displays are eye-gouging tables. I made the chart I suggested, and even with Excel Defaults, it beats the heck out of the pie chart.