Scale Distortion Math Example 1
Follow the full solution, then compare it with the other examples linked below.
Example 1
easyTwo graphs show the same data (unemployment: 4% to 5%). Graph A: y-axis from 0–10%. Graph B: y-axis from 3.5%–5.5%. Describe what each graph communicates visually and which is more honest.
Solution
- 1 Graph A (0–10%): the 1% increase looks small — the bar rises modestly from 40% to 50% of the axis height
- 2 Graph B (3.5–5.5%): the same 1% increase looks enormous — the bar rises from near the bottom to near the top of the compressed axis
- 3 True change: relative increase — significant but not catastrophic
- 4 Graph A is more honest for showing absolute magnitude; Graph B exaggerates relative change
Answer
Graph A (wider scale) shows true magnitude honestly; Graph B's compressed scale makes the change look much larger.
Scale selection dramatically affects visual impression. There is no universally 'right' scale, but starting at 0 for bar charts prevents area distortion. For line charts, the appropriate scale depends on the question being asked (absolute change vs. relative change).
About Scale Distortion
Scale distortion occurs when a graph's axis does not start at zero or uses inconsistent intervals, making small differences appear large or large differences appear small.
Learn more about Scale Distortion →More Scale Distortion Examples
Example 2 medium
A graph uses a logarithmic scale for a dataset ranging from 1 to 1,000,000. Explain when a log scale
Example 3 easyA pictograph shows a 2021 salary twice as large as a 2020 salary by doubling both the height AND wid
Example 4 hardA company's revenue chart has an x-axis with uneven time intervals (2010, 2012, 2016, 2017, 2018). T