What is a common way charts can mislead readers?

• A. Misleading scales
• B. Clear labeling
• C. Large sample size
• D. Consistent units

Answer: (A)

Charts influence how we perceive data through the scales on their axes. If the axis starts at a value above zero, or if tick marks are uneven or the axis is overly compressed, small differences can look much larger and a trend can appear steeper than it actually is. Our eyes judge magnitude from the height or length of elements, so the scale directly shapes our impression of the data. Clear labeling, a large enough sample, and consistent units help readers understand the true values and comparisons, while a misleading scale masks or exaggerates differences. A common example is starting the vertical axis at a nonzero value, which can make modest changes seem dramatic and distort the viewer’s takeaway.