Or what if you're one of the 5 who would die in a bathtub fall. Would you quit bathing? It's post hoc reasoning.
On Apr 13, 2009, at 5:02 PM, Michael Smith wrote: > > > Hmmm. > > But what if you are one of those two? > > --Mike > > On Sun, Apr 12, 2009 at 10:31 PM, Christopher D. Green > <[email protected]> wrote: > > > > Here's another example of misleading medical statistics example you > might want to use in class. > http://www.guardian.co.uk/science/2009/apr/11/bowel-cancer-soya > > The report says that more soy in the diet (it doesn't say how much > more) can reduce women's chance of death from bowel cancer by 30%. > (Actually, it says those in the top third of soya intake had a 30% > decrease in bowel cancer deaths, compared to the bottom third -- > NOTE: not from the national average -- but it doesn't give any > indication of how much soy each group actually ate.) > > So let's work the numbers. 16,600 women die from bowel cancer per > year in the UK. There are about 60 million people in the UK. Half > are female: 30 million. Lose the 20% children and we have 24 > million women. > > So, the chance of dying of bowel cancers for women in any one year is: > 16,600/30 million = .0007, or 7 in 10,000. > > A 30% reduction would lower that chance to 5 in 10,000. > > So (even if the causal implication that is not actually > demonstrated here were correct), if increasing your soy intake by a > fair bit could decrease your chances of dying by bowel cancer by > 30%, that would represent a tiny reduction of just 2 in 10,000 per > year. > > > Chris > -- > Christopher D. Green > Department of Psychology > York University > Toronto, ON M3J 1P3 > Canada > > > 416-736-2100 ex. 66164 > [email protected] > http://www.yorku.ca/christo/ > > ========================== > > > --- > To make changes to your subscription contact: > > Bill Southerly ([email protected]) > > --- > To make changes to your subscription contact: > > Bill Southerly ([email protected]) Paul Brandon Emeritus Professor of Psychology Minnesota State University, Mankato [email protected] --- To make changes to your subscription contact: Bill Southerly ([email protected])
