KR wrote:
>
> Hi,
>
> If I have two different surveys from which I calculate values of P1
> and P2, would Cov[P1, P2]=0? The two surveys were performed in
> different years and have different sample sizes.
You cannot have a covariance without a pairing between the elements of
the two sets of observations; covariance is a measure of whether
bigger-than-average measurements in one set tend to be paired with
bigger-than-average measurements in the other.
You cannot have a pairing with different sample sizes.
Explain what question you're trying to answer; maybe somebody can tell
you what statistics you should be using.
Robert Dawson
.
.
=================================================================
Instructions for joining and leaving this list, remarks about the
problem of INAPPROPRIATE MESSAGES, and archives are available at:
. http://jse.stat.ncsu.edu/ .
=================================================================
