October 28th, 2013 at 12:38 UTC by Ross Anderson
Britain has just been hit by a storm; two people have been killed by falling trees, and one swept out to sea. The rail network is in chaos and over 100,000 homes lost electric power. What can security engineering teach about such events?
Risk communication could be very much better. The storm had been forecast for several days but the instructions and advice from authority have almost all been framed in vague and general terms. Our research on browser warnings shows that people mostly ignore vague warnings (“Warning – visiting this web site may harm your computer!”) but pay much more attention to concrete ones (such as “The site you are about to visit has been confirmed to contain software that poses a significant risk to you, with no tangible benefit. It would try to infect your computer with malware designed to steal your bank account and credit card details in order to defraud you”). In fact, making warnings more concrete is the only thing that works here – nudge favourites such as appealing to social norms, or authority, or even putting a cartoon face on the page to activate social cognition, don’t seem to have a significant effect in this context.
So how should the Met Office and the emergency services deal with the next storm?
While driving to work I heard a council official telling people not to take their own saws to fallen tree branches, but wait for council crews. A left-leaning listener might interpret this as a lawyerly “Right, I’ve covered by backside by saying that” while a conservative-leaning one might hear a trade unionist line “Don’t you dare take bread out of the mouths of the workers!” Government spokespersons score pretty low on most trust scales and people tend to project on them the lowest motives of whichever party they support least. It would surely have been better to say “If a road is blocked by a tree, just call us and we’ll send a crew round. If you absolutely can’t wait, take care! There are accidents every year when someone cuts halfway through a branch, and it cracks and the rest of the tree falls on them.”
Similarly, in the run-up to the storm, the weather forecaster might usefully say “We had three people unfortunately killed last time in 2013, and 30 killed in the big storm of 1987. Most fatal injuries are from falling trees, then flying debris, then people being washed out to sea. So stay at home if you can. If you really must go out, keep your eyes open, so you can duck if something is blown your way. And don’t stand right on the seafront to admire the waves. Twenty-foot waves can be awesome, but every so often a forty-foot one comes along. So keep your distance.”
A useful way of thinking about it might be this: what advice would you yourself heed if it came from the politician you trust the least? You won’t buy any of his argument, but you may well accept a reminder of a fact that you knew already.