The Paling Perspective Scale©
What is It?
The Paling Perspective Scale was designed as an easy to use "Richter Scale for Risks" that allows non-technical people to begin to put risks into perspective. The idea was that people would be helped if they could compare some new worry alongside everyday risks that they were at home with.
Paling Scales offer a graphical way for the public to compare the odds of different risks in a visual context in a way that cuts through the sometimes-misunderstood technical language used by risk assessors. These visual formats can transform data into useful information that helps people to make their own judgments about the issues that concern them.
NOTE: The basic versions of these scales show only the probabilities not the consequences of a particular risk. (A really big risk is something that has both high probability of happening and also serious consequences, of course.) 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 people are concerned about.
What Does it Accomplish?
The perspective scale encourages members of the public to bear in mind that most things in life come with some risks associated with them. Thus, when deciding what to do about a new, unfamiliar risk, it makes sense to put it into perspective by viewing it in the context of all the other risks of daily life.
The key to putting some unfamiliar risk into perspective is seek out the answer to 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?" If need be, get someone to transcribe the technical numbers used by mathematicians into a simple estimate of probability. (Obviously, one should compare apples with apples as far as possible: annual risks with other annual risks, etc.) Then it is easy to plot the odds of each risk on the Paling Perspective Scale and to move towards better understanding.
Many risk communicators are cautious about comparing some new risk with a commonly known everyday risk. This is in part because whatever the particular "anchor risk" that is chosen, it can carry misleading emotional or other factors associated with it. (See http://www.psandman.com/articles/cma-3.htm).
Our view is that a large part of this concern is removed if, instead of making comparison with just a few anchor risks, a whole group of them are included and presented as a zone of risks with which the average member of the public is at home.
Using a zone of risks (and inviting others to add the probability numbers for risks that they feel make for fair comparisons) should reduce any suspicion or resentment that the risk communicator is unfairly biasing the message to manipulate the decision of the listener.
Whatever the concerns of academic risk assessors, there is absolutely no doubt that most members of society naturally seek to understand some new risk by first comparing it with other everyday risks that they feel familiar with. Doctors, engineers, the media and the general public all welcome some attempt to put unfamiliar risks into perspective and we consider that our scale is the best starting point for this
Who Uses It?
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.
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.