A modification of the Hartung-Knapp confidence interval on the variance component in two-variance-component models
We consider a construction of approximate confidence intervals on the variance component in mixed linear models with two variance components with non-zero degrees of freedom for error. An approximate interval that seems to perform well in such a case, except that it is rather conservative for large was considered by Hartung and Knapp in [hk]. The expression for its asymptotic coverage when suggests a modification of this interval that preserves some nice properties of the original and that...