David Spiegelhalter's blog

I was lucky enough to get included in the Horizon programme on Infinity last night, talking about the old monkey-Shakespeare issue. Of course most of my rambling contribution was (rightly) cut, so here’s a few background details for anyone interested.

There has been extensive coverage of a box of 6 eggs found to be all double-yoked:an event that was given odds of a trillion to 1 against. This was based on the British Egg Information Service saying 0.1% ( 1 in 1000) eggs were double-yoked, and so getting six of these required these odds to be multiplied 6 times. In fact this gives 1 in 1,000,000,000,000,000,000, but which was reported as a trillion (now usually taken as 1,000,000,000,000).

The Daily Mail did a good demolition of this story, and it is a good example of what can go wrong when people try and work out chances.

Some items to watch

A video has gone on Youtube called Professor Risk as part of a series made for the Cambridge 800 years anniversary. To be honest it's a bit lightweight when it comes to risk, and all the subtle bits got cut. We filmed a whole lot more including my GP taking my blood, discussing statins and screening for prostate cancer.

Elsewhere on this site we talk about the difficulties in making reliable rankings of footbal teams, but at least people can agree that winning matches is a reasonable way to measure the quality of a team. Hospitals are different - even something 'obvious' such as mortality statistics may not be the best way to asses patient safety. This is an article that appeared in the Times on December 2nd, with suitable links added.

This appeared in the Times on November 3rd and is based on the excellent lecture that got David Nutt sacked as chair of the Advisory Council for the Misuse of Drugs (although he might still be in post if he had only added that it was delivered in his personal capacity). Nutt has suffered the consequences of repeatedly breaking the taboo of comparing the risks of the legal and wholesome (horse-riding) or long-established (alcohol and smoking), with the illegal and "impure" Ecstasy and cannabis.
The version below contains links to sources and a few comments and corrections.

“Brits three romps from celeb sex” headlined the Sun on Friday, adding that “boffins at Cambridge University have calculated every person in the UK is linked to a star through their sexual partners — with just three steps separating the average person from a steamy celeb romp”.

Random events tend to cluster, and just to illustrate this we've suddenly got a burst of coverage of our work:

The Worrier’s Guide to Risk is intended to be a one-page check-list to help people make more sense of the seemingly unending series of stories on risk. This is a first draft, that has been produced in association with the Risk and Regulation Advisory Council, which is an independent advisory group which aims to improve the understanding of public risk and how best to respond to it in making and implementing policy.