(67) Visualizing very small risks

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Some risk communication situations require helping people to visualize just how rare very rare events are. A common example occurs in prenatal genetic testing. If a couple has no other risk factors, the baseline risk of genetic diseases such as Down Syndrome is often much smaller than even 1 in 1000 (0.1%). Visually showing this ratio is challenging.

What’s special about this image?

This simple graphic reinforces the smallness of the risk by comparing the dot and the much larger circle. The design emphasizes gist-level emotional reaction more than thinking and cognition.

With this graphic, people's gist accuracy was significantly higher and their risk perceptions were lower than with other images. We recommend this graphic.
  • My goal
  • Awareness of risk
  • Raise or lower concern
  • Details or gist?
  • Verbatim recall
  • Data I have
  • Risk estimate
  • Test result
  • Health conditions
  • Down syndrome
  • Graphic type
  • Area graph