I found this over on FailBlog, which typically isn’t a source of great visualization material. However, this poll result from the Washington Post has so many errors, I had to post it.
At first glance, it seems that there’s an overwhelming “yes”, as evidenced by the red bar. But look closely at the percentages inside the bars, and you see they are both 50% . Look closely at the legend across the bottom, and the entire legend is 50%. What this really means is that the results (once you account for a reasonable margin of error) are essentially equal, roughly 49.9% vs 50.1%.
At a panel this week at VisWeek, “Changing the World with Visualization”, Sarah Cohen made the comment that they typically don’t label charts very well because they aren’t expected to leave the newsroom. Evidently this one snuck out.
Online Poll Fail « FAIL Blog: Epic Fail Pictures and Videos of Owned, Pwnd and Fail Moments.
Seems that the problem is automatic scaling gone too far. A good lesson there.