Testing equality of scale arises in many research areas including clinical data analysis. In contrast to procedures for tests on means, tests for variances derived assuming normality of the parent populations are highly non-robust to non-normality. Levene type tests are well known to be robust...

Positive and negative predictive values are important measures of accuracy whenone compares the accuracy of diagnostic tests. When more than one diagnostic tests areavailable, one may has to choose one of the possible diagnostic tests due to cost, time, orethical reason. We consider a pair study...