Pictures that mislead

When a bar graph is decorated with more pictures and colour, it is called an information graphic, or infographic. Infographics catch our attention and show information quickly and beautifully. But your book warns: a fancy picture can also mislead.

The tallest mountain on each continent is first drawn as columns of the same width. Then the columns are changed into triangles, which look more like mountains. But the taller triangles are also drawn wider! The data only tells us the heights, not how wide the mountains are. The picture suggests something the data never said.

Next the book draws an imaginary mountain range with all seven mountains. It looks realistic, but in it Everest seems twice as tall as Elbrus. Check with numbers: Elbrus is 5642 m, and twice that is 5642 × 2 = 11,284 m. Everest is 8848 m, much less than 11,284 m. So Everest is not twice as tall as Elbrus, and the picture is wrong.

So when you make or read an infographic, check it against the numbers. Be careful not to mislead others, and not to be misled yourself.