  The receiver operating characteristic curve is a widely used performance
indicator for diagnostic tests. By its nature some segments of the curve are
more relevant for clinical applications than others. A suitably specified
partial area under the curve aggregates the information carried by the
clinically relevant segments. Our main result shows joint asymptotic normality
of vectors of possibly dependent distribution-free estimators of these partial
areas. We additionally show correctness of the empirical bootstrap in this
situation and use it to construct asymptotically correct multiple contrast
tests for partial areas under receiver operating characteristic curves. Our
analytical results indicate that a partial area under the curve may be
preferable to the widely used total area under the curve as a basis for
performance comparisons between two diagnostic tests.
