Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Models and Confidence Intervals for True Values in Interlaboratory Trials

Published

Author(s)

Hariharan K. Iyer, Chih-Ming Wang, T Mathew

Abstract

We consider the one-way random effects model with unequal sample sizes and heterogeneous variances. Using the method of generalized confidence intervals, we develop a new confidence interval procedure for the mean. Additionally, we investigate two alternative models based on different sets of assumptions regarding between group variability and derive generalized confidence interval procedures for the mean. These procedures are applicable to small samples. Statistical simulation is used to demonstrate that the coverage probabilities of these procedures are close enough to the nominal value so that they are useful in practice. Although the methods are quite general, the procedures are explained with the backdrop of interlaboratory studies.
Citation
Journal of the American Statistical Association
Volume
99
Issue
468

Keywords

coverage probability, generalized pivotal quantity, heterogeneous error variances, ISO gum, one-way random effects model, type-B assumptions
Created December 6, 2004, Updated February 19, 2017