Reproducibility and repeatability how to evaluate

Cornelis — Tue, 10 Oct 2017 14:04:59 GMT

Dear all,

SAS offers PROC VARCOMP where you can use it for calculation of repeatability and reproducibility using variance components.

I have downloaded a paper from Caroli that demonstrates the coefficient of repeatability/reproducibility calculations.

http://www.sascommunity.org/seugi/SEUGI1998/caroli_posters.pdf

The coefficient of reproducibility is defined as the probability for an analytical measure to be produced …

R = Var(Sample) / (Var(Sample) + Var(Error)) .. in %

Var(sample) = variation of sample, var(Error) = variation of error calculated by REML.

So far as I can see, coefficient of reproducibility represents the ratio between variation sample and total variation. A value of R = 93 % has been found in the paper and the questions are:

What is acceptable criterion of coefficient of reproducibility? > 90 %?
Is there any reference that will tell more about coefficient of reproducibility?
How do we calculate the reproducibility, i.e. the error “± value” with 95 % confidence limit? Usually, the reproducibility is frequently defined as √2 * 1.96 * SD, where SD = standard deviation. This value is different from the coefficient of reproducibility and what can we do with both calculations?

Your contribution is highly appreciated.

Best regards,

Cornelis.

Re: Reproducibility and repeatability how to evaluate

PaigeMiller — Tue, 10 Oct 2017 14:18:48 GMT

What is acceptable criterion of coefficient of reproducibility? > 90 %?

I'm pretty sure this would be user judgment, based upon the understanding of the application being analyzed.

Is there any reference that will tell more about coefficient of reproducibility?

Have you tried using a search engine?

How do we calculate the reproducibility, i.e. the error “± value” with 95 % confidence limit? Usually, the reproducibility is frequently defined as √2 * 1.96 * SD, where SD = standard deviation. This value is different from the coefficient of reproducibility and what can we do with both calculations?

While I don't know the answer, it is unlikely that the reproducibility is normally distributed, so I doubt that the standard formulas apply here. But I don't really understand what question you are asking, specifically, you want a ± confidence interval for what quantity?

topic Reproducibility and repeatability how to evaluate in Statistical Procedures

Reproducibility and repeatability how to evaluate

Re: Reproducibility and repeatability how to evaluate