"Making an evidence presentation is a moral act as well as an intellectual activity. To maintain standards of quality, relevance, and integrity for evidence, consumers of presentations should insist that presenters be held intellectually and ethically responsible for what they show and tell. Thus consuming a presentation is also an intellectual and moral activity." (Beautiful Evidence)
That paragraph speaks to the three persons that coexist in me: The journalist, the educator, and the information designer. Its main theme is central in The Functional Art: Correctly presenting data and phenomena in a graphic is not just a professional endeavor; it is also —above all— an ethical mandate. So is openly and candidly discuss mistakes, yours and others'. In infographics and visualization, the decisions we make on how to encode information, how to organize it, and how to present it, should be guided by a simple principle: Whatever improves citizens' interest in a relevant topic and their awareness and understanding of it is morally and ethically* good; whatever obscures the subject, trivializes it, or misleads audiences is bad.
There are cases where we can clearly identify conscious disregard for this principle, although they are rare: Fox News' many egregious (see pie chart below) and epically flawed charts should be a tempting research topic for PhD students.
All media organizations commit blurrier sins every now and then, though. The best out there sometimes publish graphics that I'd argue are ethically questionable even if designers made them with noble goals in mind. Let's mention The Economist's occasional love for truncated axes in bar charts (needless to say, a bar chart baseline should always be 0), or this op-ed by Charles M. Blow, addressing inequality and unemployment in the U.S. As many of Blow's articles, this one must be praised for its reliance on empirical evidence, something that is not common among opinion writers anywhere. Unfortunately, when it comes to charting, we find this (see it complete here):
I'd argue against this graphic by evoking an old adage: If precise comparisons are crucial, circles are not a good choice. Can you really see that a person in the top income quintile would save ten times more than an individual in the middle quintile if income taxes were reduced by 20%? If you are absent minded, as I am, you'd walk away from this chart thinking that differences in savings are much less worrying than they really are.
A very recent case of misdeed is this unfortunate series of maps about the European economic crisis. They are among the best examples I've seen of how not to design cartograms. Let's take just a small portion of the graphic (above): Without reading the numbers, quickly tell me if the unemployment rate is higher in Spain or in Portugal. There you go: Portugal looks like the worst offender in Europe, when it is doing better than Spain and Greece...
(The ethics of infographics has been a concern of mine for many years. Read this manifesto at the Harvard Nieman Watchdog site to learn more.)
* I am using the terms morals and ethics in the sense explained here.