Re: Simpson paradox

On Wed, 23 Nov 2005 22:57:19 +0100, Landini <my.address.is@xxxxxxxxx>
wrote:

> Dear all
> I'm an agronomists and i work in a test facility in Italy
> In many field trials with insecticides sometimes happen something that seems
> to Simpson's paradox
> I will try to explain better with an example

Yes, the disproportionate Ns give you Simpson's paradox,
so that the overall sums are misleading.

[snip, example of insecticides]
>
> Wich is the CORRECT statistical model that must be applied???
> Where i can find any ciatation of articles that can be founded also in italy
> about this argument????

It is also called the ecological fallacy, among other names.
Perhaps that will lead to citations that are especially relevant.

--
Rich Ulrich, wpilib@xxxxxxxx
http://www.pitt.edu/~wpilib/index.html
.