Is your donut chart sending the wrong signals?

Back on July 25, 2009 I blogged about Bullfighting the Mehrabian Myth – a bogus claim about communication (as shown above in a simple horizontal bar chart) that 7% of our meaning is from words, while 38% is from tone of voice, and 55% is from body language.

Those mythical percentages often are illustrated via pie charts (as shown above), or related donut charts. Just because you can do something with PowerPoint (or another graphics program) doesn’t mean that you should.  

The worst donut chart version (shown above) I have seen comes from a Tony Robbins web page titled Are you sending the wrong signals? Compare it to the pie chart shown above, and you will see the angle depicting that 7% for words is larger than it should be. Also shown above is how that angle compares with a right angle, which should represent 25%. It’s almost half! I got out a protractor, and found it represents 12%, while tone of voice actually is 30%, and body language is 58%.

Another poor way to display those three percentages is via an exploded 3-D donut chart, as was done by ToolsHero.

Still another poor way to present the percentages is via a pointless row of three donut charts, as was done on web pages both by MindMaven and Slidemodel.

Yet another way to mess things up is by putting down the wrong percentages, like at Kizan, who had a donut chart saying words were 8% rather than 7%, and tone of voice was 37% rather than 38%.

There also even are pyramid charts, like the one shown at 3:30 in this seven minute YouTube video, which I don't think communicates effectively - it is way less clear than a simple bar chart.