Is A Poor Chart Worse Than No Chart?

Kaiser at  Junk Charts posted on a New York Times chart from the Sept. 6, 2008 op-ed piece “Let’s Talk About Sex“. Kaiser and his commenters agreed that the chart was not effective.

The chart, partially reproduced to the right, shows 4 teenage sex indicators for 28 countries. The chart designer chose to use bubble size to compare the other country rates to the USA rate. The result is a confusing chart.

I have several concerns with this chart: 

1. Relationship to the article – I read the article to see how the chart fit into the writer’s discussion.  To my surprise, the writer did not mention the chart at all.  The chart stands on its own, with no relationship to the article.

2.  Chart Design – Using bubble size to compare rates is a poor charting technique. I created this dot plot of 1970 and 1998 teenage birthrates as an alternative to the Times chart.

3. Missing Data Analysis – Charts, an important tool in data analysis, are not the same as data analysis. We need to interpret, evaluate, synthesize our data to gain understanding. The Times’ article and chart do not provide any interpretation, analysis or synthesis. Why have a chart if we  are going to ignore it?

There are a number of important findings in the data that the author could have pointed out:

  • All countries except Ireland had a decrease in teenage birthrate from 1970 to 1998
  • 1998 teenage birthrates varied from a low of 4.6 births per 1,000 woman in Japan to a high of 52.1in the US
  • The US 1998 teenage birthrate was nearly 70% greater than the closest countries of New Zealand and Britain 
My blog post title asks the question – “Is a poor chart worse than  no chart?“.  The New York Times’ article was not improved by the graphic. Since the graphic was so poor, it likely took focus from the author’s words for many readers without providing any insight into the issue being discussed. In this case, the poor chart was definitely worse than no chart.
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