INFO VISUALIZATION: USA Today has to be the worst legit news organization when it comes to creating useful and informative information visualizations. (If an information visualization isn’t informative, then what the hell is it there for?) I ran across this train-wreck of a graph today in something called “USA Today Snapshots,” which I’m guessing is what they call those little animated distractions at the bottom of the section pages in their printed version.
The general idea of this graph is clear: there are more massage therapists now then five years ago. Fine. But pay attention to the numbers: the growth of massage therapists was well over 300%, but does this graph make that clear? No, not at all; the length of the 2004 arm is exactly 200% of the 1999 arm. Compare this presentation to a very simple graph I made in about 10 minutes, it becomes very clear how poor the USA Today version is at making its point.
“But you’re assuming the left of the graphic is the Y axis,” you may be saying. Or perhaps, “but we don’t know that this is a linear graph.” Yes, I am assuming these things because the graph gives me no indication that these assumptions are wrong.
All but one of Tufte’s Six Principles of Graphical Integrity is broken by this display (not to mention his rules about "Chart Junk" and "Data-Ink Maximization"):
The representation of numbers, as physically measured on the surface of the graphic itself, should be directly proportional to the numerical quantities represented.
Clear, detailed, and thorough labeling should be used to defeat graphical distortion and ambiguity. Write out explanations of the data on the graphic itself. Label important events in the data.
Show data variation, not design variation.
In time-series displays of money, deflated and standardized units of monetary measurement are nearly always better than nominal units. (n/a for this graph)
The number of information-carrying (variable) dimensions depicted should not exceed the number of dimensions in the data.
Graphics must not quote data out of context.
The Visual Display of Quantitative Information by Edward Tufte