Performance Evaluation of Ground Water Reference Material by Statistical Methods
DOI:
https://doi.org/10.17713/ajs.v27i1&2.533Abstract
As part of the Danish ground water monitoring program a multicomponent reference material for laboratory use has been developed. After the certification procedure was completed, further analysis was undertaken to investigate any possible effect of the analytical methods used by the laboratories. In the present case, a group of similar compounds were selected for the statistical analyses. Data was imbalanced, therefore a mixed model approach has been applied using the MIXED procedure of SASâ. Method effect was significant in two cases out of six. Some of the data sets caused problemswith non positive definite G-matrices, probably because of too sparse data.
References
ISO Guide 30: Terms and definitions used in connection with reference materials, 1992.
ISO Guide 35: Certification of reference materials - general and statistical principles, 1989.
ISO-REMCO N282 Rev Final Draft (1993): Quality system for the operation of a reference material producer, 1993.
F.C. Leone, L.S. Nelson, N.L. Johnson, and S. Eisenstat. Sampling distributions of variance components ii. empirical studies of unbalanced nested designs. Technometrics, 10 (4):719–737, 1968.
R.B.McHugh and P.W. Jr.Mielke. Negative variance estimates and statistical dependence in nested sampling. J. Amer. Statist. Assoc., 63:1000–1003, 1968.
W.A. Jr. Thompson. The problem of negative estimates of variance components. Annals of Mathematical Statistics, 33:273–89, 1962.
Downloads
Published
Issue
Section
License
The Austrian Journal of Statistics publish open access articles under the terms of the Creative Commons Attribution (CC BY) License.
The Creative Commons Attribution License (CC-BY) allows users to copy, distribute and transmit an article, adapt the article and make commercial use of the article. The CC BY license permits commercial and non-commercial re-use of an open access article, as long as the author is properly attributed.
Copyright on any research article published by the Austrian Journal of Statistics is retained by the author(s). Authors grant the Austrian Journal of Statistics a license to publish the article and identify itself as the original publisher. Authors also grant any third party the right to use the article freely as long as its original authors, citation details and publisher are identified.
Manuscripts should be unpublished and not be under consideration for publication elsewhere. By submitting an article, the author(s) certify that the article is their original work, that they have the right to submit the article for publication, and that they can grant the above license.
How to Cite
