## Definitions

Sorry, no definitions found. Check out and contribute to the discussion of this word!

## Etymologies

Sorry, no etymologies found.

## Support

Help support Wordnik (and make this page ad-free) by adopting the word simpson's paradox.

## Examples

Sorry, no example sentences found.

sionnach commented on the word simpson's paradox

Suppose we want to compare two treatments, A and B, for a particular disease. 160 patients are given A - 60 recover; 230 patients receive B and 65 recover.

Clearly, treatment A, with a cure rate of 60/160 = 38%, is preferable to treatment B, with cure rate 65/230 = 28%. Right?

Maybe not. What if we are also given the recovery rates by sex, as follows:

men : A 20/100 (20%) B 50/210 (24%)

women: A 40/60 (67%) B 15/20 (75%)

overall: A 60/160 (38%) B 65/230 (28%)

Thus, even though A appears better overall, clearly treatment B is better both for men and for women. This contradiction is known as Simpson's paradox.

October 16, 2007