The Paling Perspective Scale is an easy to use "Richter Scale for Risks" that allows non-technical people to put risks into perspective by comparing them to everyday worries that they are "at home" with. It also allows the risks from different options to be compared side by side.
Paling Scales offer a graphical way for the public to compare risks in a visual context that cuts through the often-impenetrable "voodoo technical language" often used by risk assessors. These visual formats transform data into useful information that allows people to make their own judgments about the issues that concern them.
The key to using these scales is to try to transcribe the different technical numbers used in different subjects into a common familiar unit that the public can relate to. In other words, the experts should start by giving their best estimate of probability for a defined risk under a stated set of circumstances. The objective is to answer the simple question "What are the odds of this risk happening to me or a member of my family under a given set of circumstances?" Then it is easy to plot the odds of each risk on the Paling Perspective Scale and to move towards insightful comparisons. Obviously one should compare apples with apples as far as possible: annual risks with other annual risks etc.
The basic versions of the scale reflect only the probabilities not the consequences of a particular risk. However, providing the seriousness of the risk is reflected in the words used to describe it, this tool is very helpful to bring perspective to the issues that individuals are concerned about.
Much more information is available in the books Helping Patients Understand Risks and Up To Your Armpits In Alligators?.
PROFESSIONAL RISK COMMUNICATORS FROM INDUSTRY AND GOVERNMENT
have used the Scale to communicate about a wide variety of risks with the public, the media and regulators. Often it is helpful to compare some unknown risk with a range of similar risks that the public is “at home with”.
For any who is skeptical about comparing risks, we advocate trusting the public to put their own figures on the scale (based on numbers from third parties including government agencies) to establish a “Home Base Zone”. This avoids the claim that the risk communicator is forcing them to compare some new risk with some risk that is chosen by the professional and which might thus generate resentment in the listener.
DOCTORS LEARNED ABOUT THE SCALE
from an article in Scientific American in May 1995 and immediately realized its value as a tool for communicating medical risks to patients in informed consent interviews. Several peer-reviewed papers on the Scale have been published in the medical literature and are listed in John Paling’s biography.
View a blank Scale. (It may take a few moments to download.)
Blank Scale One
Blank Scale Two
Scales showing risks with which we are “at home”
Simplified version - color
Simplified version - black and white
Other versions of the Scale.
Example One - Risks From Dental X-rays
Exampe Two - Risks from Chemicals in water
Example Three - Estimates of arsenic levels in soil
Example Four - Risk from SmallPox
Example Five - Blood transfusion Risks
Several different formats of the scale have been produced and templates of all these may be downloaded for use by third parties:
For those who wish to do risk management for organizations, it is possible to use variations of The Paling Scales to visually show the odds and the consequences if the latter can be converted into a common unit such as (however distasteful) converting the loss into some measure of money. This is covered in the book Up To Your Armpits In Alligators? How to sort out what risks are worth worrying about.