To assist in the wider appreciation of the issues raised, a short commentary on the papers has been commissioned from the well-known science writer, Geoff Watts. (For full commentary, please visit http://www.rss.org.uk/publications/risk.html )
The trouble with risk Toss a fair coin and you know that the chances of it landing head or tail side up are identical. But suppose you toss it seven times in succession and see, to your surprise, that tails have come up on each occasion; what is the likelihood of an eighth toss giving yet another tail? Slim, would you say? Sufficiently so to stake your life against it?
No. And as this dilemma is the oldest entry in the statisticians' book of trick questions, the reason is probably familiar. Chance has no memory; no matter how many times that tails come up, the likelihood of it happening once more is still 50:50. But, familiar or not, something in us resists that conclusion. Because we know that a run of eight successive tails is unlikely, we can find it difficult to accept that the odds operating on the eighth toss really are those in force on the first. But, as so often in statistics, the truth is not immediately obvious, and sometimes runs counter to intuition. The temptation to make the big wager may be hard to resist.
The coin example is trivial. But think instead of risks to health, life or property; and instead of flipped coins think of heart attacks, car crashes, smoking, HIV, crime or earthquakes. Misjudging the likelihood of events like these is self-evidently disastrous. Yet for many reasons - some clear, others less so - we do frequently misjudge the nature and scale of the risks encountered in everyday life. And even when the reality is spelled out to us, we don't always respond appropriately.
Like other professionals who study risk or deal with its consequences, statisticians are conscious that a world ever more dependent on science and technology creates an ever greater need to cope with these matters. But many of us are ill-equipped to do so. For this reason the Royal Statistical Society is trying to dispel some of the confusion about risk.
The June 2003 issue of one of its regular journals, Statistics in Society, includes a series of papers by people concerned with particular types of risk: those already mentioned, and others. They and their fellow experts have to communicate their findings to a public that is quite often, and quite understandably, baffled if not disbelieving. Professionals in other fields - legislators and policy advisers, for example - also need to appreciate the message. Drawing mainly on the examples offered by the authors themselves, this brief commentary will extract and itemise some of the underlying problems and principles.
Articles include:
The communication of risk
D. R. Cox and S. C. Darby
Introduction to the papers on 'The communication of risk'
A. F. M. Smith
Human immunodeficiency virus risk: is it possible to dissuade people from having unsafe sex?
J. Richens, J. Imrie and H. Weiss
http://www.blackwell-synergy.com/links/doi/10.1111/1467-985X.00268/abs/
Communicating risk--coronary risk scores
M. Graham and E. Clavel
http://www.blackwell-synergy.com/links/doi/10.1111/1467-985X.00269/abs/
Tobacco--the importance of relevant information on risk
S. C. Darby
http://www.blackwell-synergy.com/links/doi/10.1111/1467-985X.00270/abs/
Tobacco: public perceptions and the role of the industry
D. Simpson and S. Lee
http://www.blackwell-synergy.com/links/doi/10.1111/1467-985X.00271/abs/
Communication of risk: health hazards from mobile phones
D. R. Cox
http://www.blackwell-synergy.com/links/doi/10.1111/1467-985X.00272/abs/
Crime victimization: its extent and communication
P. Wiles, J. Simmons and K. Pease
http://www.blackwell-synergy.com/links/doi/10.1111/1467-985X.00273/abs/
Accidental fatalities in transport
A. W. Evans
http://www.blackwell-synergy.com/links/doi/10.1111/1467-985X.00274/abs/
Communicating the risks arising from geohazards
M. S. Rosenbaum and M. G. Culshaw
http://www.blackwell-synergy.com/links/doi/10.1111/1467-985X.00275/abs/
Full table of contents are available at http://www.blackwell-synergy.com/links/toc/rssa
Journal
Journal Of The Royal Statistical Society