Misleading charts
Spot charts that give a wrong impression, such as a cut axis or pictures of different size, draw them honestly and choose headlines that the data support.
- Germany: grade 5
Guide
A chart can be correct and still mislead. The most common trick is a cut axis: the vertical axis starts at a number above 0, so small differences look big. A break mark on the axis (a small zigzag) shows that part of the axis is missing.
Another trick is pictures of different size: if one picture is drawn twice as wide and twice as high, it covers four times the area. Our eyes compare areas, so the difference looks much bigger than it is.
Before you trust a chart, check three things: where does the axis start, is the scale even, and are the pictures the same size? A good headline says only what the numbers show. The data of the studio are made up for practice.