L’Aquila: earthquake, verdict, and statistics

Yesterday I read this blog entry by Peter Coles, a Professor of Theoretical Astrophysics at Cardiff and soon in Brighton, about L’Aquila earthquake verdict, condemning six Italian scientists to severe jail sentences. While most of the blogs around reacted against this verdict as an anti-scientific decision and as a 21st Century remake of Giordano Bruno‘s murder by the Roman Inquisition, Peter Coles argues in the opposite that the scientists were not scientific enough in that instance. And should have used statistics and probabilistic reasoning. While I did not look into the details of the L’Aquila earthquake judgement and thus have no idea whether or not the scientists were guilty in not signalling the potential for disaster, were an earthquake to occur, I cannot but repost one of Coles’ most relevant paragraphs:

I thought I’d take this opportunity to repeat the reasons I think statistics and statistical reasoning are so important. Of course they are important in science. In fact, I think they lie at the very core of the scientific method, although I am still surprised how few practising scientists are comfortable even with statistical language. A more important problem is the popular impression that science is about facts and absolute truths. It isn’t. It’s a process. In order to advance, it has to question itself.

Statistical reasoning also applies outside science to many facets of everyday life, including business, commerce, transport, the media, and politics. It is a feature of everyday life that science and technology are deeply embedded in every aspect of what we do each day. Science has given us greater levels of comfort, better health care, and a plethora of labour-saving devices. It has also given us unprecedented ability to destroy the environment and each other, whether through accident or design. Probability even plays a role in personal relationships, though mostly at a subconscious level.

A bit further down, Peter Coles also bemoans the shortcuts and oversimplification of scientific journalism, which reminded me of the time Jean-Michel Marin had to deal with radio journalists about an “impossible” lottery coincidence:

Years ago I used to listen to radio interviews with scientists on the Today programme on BBC Radio 4. I even did such an interview once. It is a deeply frustrating experience. The scientist usually starts by explaining what the discovery is about in the way a scientist should, with careful statements of what is assumed, how the data is interpreted, and what other possible interpretations might be and the likely sources of error. The interviewer then loses patience and asks for a yes or no answer. The scientist tries to continue, but is badgered. Either the interview ends as a row, or the scientist ends up stating a grossly oversimplified version of the story.

4 Responses to “L’Aquila: earthquake, verdict, and statistics”

  1. […] “L’Aquila: earthquake, verdict, and statistics”http:// xianblog.wordpress.com/20uila-earthquake-verdict-and-statistics/ … […]

  2. The circumstances leading up to and concerning this verdict have been well documented, in the sources cited above, and in the journal Science of the AAAS. (See, e.g., 12 Oct 2012 issue.) While there were some unfortunate things said by the Committee, I do disagree with some, like Professor Spiegelhalter, in that I think there is no reasonable way to communicate these probabilities in a crisis context which would have produced better results. The unpredictability of earthquakes by nearly any means has been a tenet of classical seismology for many years, even if there is now evidence that it is sometimes not strictly true. (For example, triggering of local quakes by large long range ones.) What appears to have happened here is that this tenet came into conflict with local practice of going outside after swarms, something which, on average, may be a useless gesture. Unfortunately, in this case, it proved the proper response. The flip side would be for seismologists and those in charge to be excessively alarmist, urging precautions under all circumstances. Setting aside false alarm fatigue, there are social costs for disruption of personal lives and livelihoods in states of extended panic. It’s possible the Committee was initially convened in order to instill calm, although it did not apparently receive a clear direction.

    The entire matter also serves, as some have commented, as a red herring, because the better response to all of this would be to actively improve building standards as is done in California and Japan. That, of course, has a cost. It is believed, for example, according to Commonwealth assessments, that many of Boston’s buildings are vulnerable to a repeat of the Cape Ann 1775 earthquake, and that while there are seismic standards on the books, they are not often enforced.

    Would an angry and dismayed populace in the U.S. argue “We should have seen it coming?” if there was a similar tragedy?

  3. I just want to clarify a minor point – the estimation of potential dangers of earthquakes is done in probabilistic terms, as well as the estimation of seismic hazard. From the wording of the post it sounds a bit like seismologists and hazard practitioners do not use probabilities and statistics to come up with their estimates of seismic hazard.

    That being said, the case of the l’Aquila event is certainly way more complex than viewing it as a simple attack on science. A lot has been said all over the web (nature actually has some good articles about the case), but one important thing everybody should think about now is how to communicate risk – especially when, as stated in the original post, the public usually seeks a yes or no answer. David Spiegelhalter has some nice thoughts about it http://understandinguncertainty.org/continuing-tragedy-l%E2%80%99aquila
    where he also points to some good blog posts about the case.

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