Confidence intervals on the intraclass correlation in the unbalanced one-way classification

Several methods are compared for constructing confidence intervals on the intraclass correlation coefficient in the unbalanced one-way classification. The results suggest that a conservative approximation of the exact procedure developed by Wald (1940) can be used for hand calculations, When the exact solution is desired, a solution procedure is recommended that is computationally convenient and allows the investigator to determine the precision of the estimate. In cases where a prior estimate of the correlation is available, researchers may select intervals based on either the analysis of variance or unweighted sums of squares estimator.