Letter: At risk of baffling everyone
Sunday 13 April 1997
Wolpert argues that even experts can be irrational and uses a brain teaser about probability to illustrate this: a disease affects 1 per cent of people. The probability that a test will detect it is 80 per cent but has a 10 per cent false alarm rate. Given a positive test result, what is the probability that a patient has the disease?
Although even Harvard medical school staff have difficulties with this, most undergraduates readily provide the correct answer to the same problem described with frequencies because then it is easy to "see" the answer. Imagine 1,000 people (think of a 100 x 10 grid). Only 10 people will have the disease and eight of these a positive test. Tests on the other 990 will give 99 false positives. The answer is clear: eight of the 107 with a positive test have the disease.
There are reports of surgeons in the US performing "preventative mastectomies" on the basis of faulty reasoning with probability of cancer. There are easier ways of talking about risks than by using baffling mathematical nomenclature.
Board creates magnetic field to achieve lift
Singer says the track was 'force-fed down people's throats'
Endangered species spotted in a creek in the Qinling mountains
Company says data is only collected under 'temporary' identities that are discarded every 15 minutes
Trend which requires crisps, a fork and a strong stomach is sweeping Mexico's streets
George Lucas criticises the major Hollywood film studios
Some experiencing postnatal depression don't realise there is a problem. What can be done?
Life & Style blogs
iPhone 6 'catches on fire and burns man's leg after bending in his pocket'
Are you ready for Crazy Doritos, the red-hot snack food craze sweeping Mexico’s streets?
Drink alcohol and eat meat to improve male fertility - but cut down on coffee, studies suggest
The inventor of the Facebook 'like' button says he never made a 'dislike' button because he feared the 'unfortunate consequences'
What lies beneath La Perla's 60 years of luxury lingerie?
Cameron is warned 'no possibility' of UK reducing immigration and that bid to bring in quota on migrant workers would be illegal
Residents should throw a street party and mix with immigrant neighbours, councils told
Russell Brand threatened with arrest after filming outside Fox News headquarters
Amal Alamuddin calls for the return of the Elgin Marbles from Britain: 'Injustice has persisted for too long'
London bus driver 'kicks gay couple off for kissing'
Lord Freud: Tory welfare minister apologises after saying disabled people are 'not worth’ the minimum wage
- 1 Jack the Ripper: Scientist who claims to have identified notorious killer has 'made serious DNA error'
- 2 Banksy arrest hoax: Internet duped by fake report claiming street artist's identity has been revealed
- 3 Drink alcohol and eat meat to improve male fertility - but cut down on coffee, studies suggest
- 4 Former East 17 frontman Brian Harvey turns up at Downing Street and 'demands to speak to Prime Minister'
- 5 The inventor of the Facebook 'like' button says he never made a 'dislike' button because he feared the 'unfortunate consequences'
£50 per day: Randstad Education Chelmsford: Are you an experienced Cover Super...
£50 per day: Randstad Education Chelmsford: Randstad Education is looking to e...
£100 - £120 per day: Randstad Education Chelmsford: Science Teacher - Maternit...
Negotiable: Randstad Education Leicester: We are recruiting for a Systems and ...