An example of magnifying effect on a risk scale

Reproduced from Lipkus, I.M. 2007. Numeric, verbal, and visual formats of conveying health risk: Suggested best practices and future recommendations. Medical Decision Making, 27, (5) 696-713.

Figure above shows a magnifying effect on a risk scale that focusses on part of the risk scale.It increases the chance of misinterpretation since it uses natural scale on a whole but uses logarithmic scale in the magnifying glass. For example, reducing a risk with probability 1 in 10 to 1 in 100 may be perceived as being the same as reducing a risk with probability 1 in 100 to 1 in 1000.The use of the magnifying glass to highlight smaller probabilities is also associated with viewing small probability events as less likely to occur; however it also undermines the perceived likelihood of occurrence for higher probability events (see Lipkus 2007).