Misleading Axis

A misleading axis is a chart trick that distorts how big a difference looks by manipulating the scale rather than the data. The most common is the truncated axis: starting a bar chart's value axis at, say, 90 instead of 0 makes a rise from 95 to 99 look like a near-doubling, when it is really a 4% change.

Other versions include inconsistent or reversed scales, broken axes hidden without a clear marker, and stretching one axis to flatten or steepen a trend at will. The defense is a habit: before reading any chart, look at the axis numbers first. The same data plotted on an honest zero-based axis often tells a far calmer story than the dramatic version.