There are lies, damned lies and statistics

There are lies, damned lies and statistics - Benjamin Disraeli

In a wonderful Nautilus article titled Five Way to Lie with Charts , one learns how to deceive using charts as the weapon of choice.

A chart’s purpose is usually to help you properly interpret data. But sometimes, it does just the opposite. In the right (or wrong) hands, bar graphs and pie charts can become powerful agents of deception, tricking you into inferring trends that don’t exist, mistaking less for more, and missing alarming facts. The best measure of a chart’s honesty is the amount of time it takes to interpret it, says Massachusetts Institute of Technology perceptual scientist Ruth Rosenholtz: “A bad chart requires more cognitive processes and more reasoning about what you’ve seen.”

To whit: Swindling Shapes

A classic way to lie with a chart is to introduce irrelevant information. In the chart on the right, the only relevant property is cone height. But, while the cone volume is irrelevant, it is also very difficult to ignore, encouraging us to assign a greater value to the larger part of the cone.

In both charts, administrative costs take almost a third of each dollar. While this matches reasonably with the left chart, the right chart seems to shrink administrative costs to something much less than a third. “Anytime you ask anyone to judge just height and ignore the other measurements,” says Rosenholtz, “it’s going to take extra cognitive load to disregard these other cues.”

So whenever a politician or corporate rep comes up with a set of "facts" supporting some agenda using charts to illustrate why this notion should be supported, analyze said charts with a grain of salt before saying yea or nea on said agenda. :)

Benjamin Disraeli, 1st Earl of Beaconsfield