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Posted at 03:16 PM ET, 05/14/2012

Weather forecasters better than doctors at giving you the odds

Some joke that weather forecasters are the only professionals who can be right half the time and keep their jobs. But the truth is, historical research says they are better than just about anyone at realistically telling you the likelihood of a certain outcome.

The Wall Street Journal had a fascinating piece on Friday about how to effectively judge risk. It discusses some of the research on risk perception, and what professionals are most skilled in this area:

Starting in 1965, for instance, U.S. National Weather Service forecasters have been required to say not just whether or not it will rain the next day, but how likely they think it is in percentage terms. Sure enough, when researchers measured the risk intelligence of American forecasters a decade later, they found that it ranked among the highest ever recorded, according to a study in the Journal of the Royal Statistical Society.

Why are meteorologists so good at assessing risk, compared to say, physicians, who score lower?

In short, it’s because weather forecasters repeat the same risk analysis day after day, get instant feedback, and learn by doing. A 1980 analysis by researchers Sarah Lichtenstein, Baruch Fischoff, and Lawrence Phillips, offers this insight:

The results [low scores] ... with physicians were in marked contrast with the superb calibration of weather forecasters’ precipitation predictions. We suspect that several factors favor the weather forecasters. First, they have been making probabilistic forecasts for years. Second, the task is repetitive; the hypothesis (Will it rain?) is always the same. In contrast, a practicing physician is hour by hour considering a wide array of hypotheses (Is it a skull fracture? Does she have strep? Does he need further hospitalization?). Finally, the outcome feedback for weather forecasters is well defined and promptly received. This is not always true for physicians; patients fail to return or are referred elsewhere, or diagnoses remain uncertain.

The experience and success of weather forecasters in judging risk has applications in daily life decisionmaking. The Wall Street Journal piece sums it up well:

Just by becoming aware of our tendency to be overconfident or underconfident in our estimates, we can go a long way toward correcting for our most common errors.

In other words, practice makes perfect.

Why is this important? Better forecasts can inform better choices...

By  |  03:16 PM ET, 05/14/2012

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