Detecting Lies

A chart could be intentionally or unintentionally misleading, making it difficult to differentiate fact from fiction. When drawing a chart, we must know how to detect and avoid lies to ensure that our chart only contains facts.

To detect lies in a chart, consider the following elements:

• Truncated axis

• Overstated axis scale

• Irregular binning

• Wrong proportions.

Truncated axis

A truncated axis is a chart axis that limits the range of values displayed by cutting off a portion of the axis. Check the labels and axes of the chart carefully. Misleading charts often have ambiguous labels that do not represent what is being measured. Additionally, distorted axes can exaggerate or minimize differences between data points.

The following example shows a truncated chart on the left and the correct version on the right. In the chart on the left, it would appear that from 2019 to 2022, the average upload speed in Greece increased. However, the real increment is only 4 Mbps.