Last month, I wrote about creative charts posted by Business Insider. Today, the news website posted a traditional stacked column chart-an effective way to show parts of a whole.

The chart, at right, shows the estimated number of Audi vehicles declining slightly between 2017 and 2025. At the bottom of each column, we see gradually increasing numbers of semi- and fully autonomous vehicle shipments.

Of course, the chart isn't perfect. The numbers within each column would be easier to read with commas, and people who are color blind have trouble distinguishing between red and green, so they may not see clearly the difference between semi-autonomous and traditional vehicles.

But this chart is much better than an example I use in class from a Cornell Daily Sun article. The chart, recreated at left, uses stacked columns incorrectly and causes obvious problems in data comparisons. The red section labeled Asian American, 15.2%, is smaller than the red section labeled Native American, .5%. Intuitively, we know there are fewer Native American students on campus than Asian American, but the visual is skewed.

Discussion:

• What are some other examples for which a stacked column chart would work well?
• Recreate the chart at left. What would be a better way to display the data?