[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Acceptance of Data Results
Since no one else has replied I thought I would stick my neck out. The
t-test is, I believe based upon the data being normally distributed.
Counting data, which usually follow Poisson statistics, may not cooperate
if the number of counts involved is not large enough to make the normal
distribution approximation valid. That may not be this case, but it is
worth bearing in mind. A second problem in general is instrumental
instabilities which may also invalidate the normal distribution
assumption.
Cheers,
Bill Prestwich
On Mon, 21 Oct 2002, Daniel Mackney wrote:
> Good day to all!
> Currently, the t-test also called the determination of Noramlized Absolute
> Difference (NAD) is applied to the sample results at my radiochemsitry lab. We
> find a problem with samples at or near background (2 to 3 pCi/g). We are
> directed to use the USACE guidance document, but it is unclear as to this
> problem.
> If anyone knows of a more detailed discussion on the use of such tests on
> samples and lab replicates, I would be interested.
> Please respond directly to me.
> DAN Mackney
> Radiochemistry Manager
> FUSRAP Maywood Storage Site
> Maywood NJ 07607
> 2018434683
> photond@earthlink.net
> ************************************************************************
> You are currently subscribed to the Radsafe mailing list. To unsubscribe,
> send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe
> radsafe" (no quote marks) in the body of the e-mail, with no subject line.
> You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/
>
>
************************************************************************
You are currently subscribed to the Radsafe mailing list. To unsubscribe,
send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe
radsafe" (no quote marks) in the body of the e-mail, with no subject line.
You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/