Sunfleet
A Sun Labs blog on social software and group collaboration.
Visualizing Risk
The New York Times published an article today on the difficulties patients have in making appropriate decisions about their medical care: In Medicine, Acceptable Risk Is in the Eye of the Beholder. It is very hard for people to understand the risks associated with medical treatments, because as humans we are particularly averse to risk when it comes to potential losses to our personal situation. What can be more personal than one's health? And as the article discusses, patients frequently make sub-optimal decisions for themselves because of this aversion.
To read more about this "irrational" behavior, start by looking into prospect theory, a seminal idea from the field of behavioral economics, developed by Kahneman & Tversky.
This article stands out for me though because it explains how visualizations of the risks can dramatically help patients understand the issues more completely. I am very interested in this integration of visualization & decision-making and would like to see more systematic analysis of why different visualizations lead to different conclusions.
From the NYTimes:
In a paper published in the June issue of PLoS Medicine, Dr. Jerome R. Hoffman says using illustrations is helpful. Pie charts, dartboards and, best of all, roulette wheels, he suggests, communicate the complex information about the probability of a good outcome more understandably.
My question is why are roulette wheels the best visualizations? Is it because, on average, patients are most familiar with the concept of risk from gambling with roulette wheels? Does that mean you should get a visualization tailored to your personal life experiences? Nerds get pie charts, barflies get dartboards, and gamblers get roulette wheels? Or is there something inherent in our visual analysis that is universal for all types of people, making roulette wheel visualizations easier to analyze than the other representations?
Posted by Joan Dimicco in "Visualization" | Comments[2]
This is what happens when you publish in PLosMedicine rather than Infoviz. (I'm sure my papers would seem just as silly to them.)
Here, check out the article itself. The Roulette Wheel: An Aid to Informed Decision Making
In this article, the authors are concerned that you may not be sufficiently aware of the probabilities and relative outcomes of different situations, and so want to illustrate to patients what possible outcomes from various treatments are.
The authors look at pie charts, and quickly dismiss them. They argue that "But presenting information in terms of two neighboring pie charts is suboptimal, because it fails to engage the viewer in terms of the relative risk associated with each of different options." That is, the pie chart doesn't--to them--imply "probability", but rather "populations."
In contrast, the authors seem to feel that the dartboard better suggests the idea that "different chance-guided areas may lead to differnet outcomes", because the patient can imagine themselves throwing a dart at the "outcomes" board.
But that, they note, has an implication of skill. In the last section, they suggest that maybe roulette is a better analogy because there is no skill involved.
Note that this is an entirely theory-based article; the authors don't test this on users. (They suggest they have set up a web site to demonstrate the phenomenon, but it appears to be down.)
Personally, I find the roulette wheel to be wasting a lot of space, and a fairly alienating presentation; I far prefer the pie chart.
Posted by Danyel Fisher on June 25, 2006 at 06:27 PM PDT #
Posted by joandimicco on June 26, 2006 at 08:20 AM PDT #