We carry out inference for the median, divided by a fixed interquantile range (IQR). It is a standardized effect or 'effect size' defined by 3 quantiles. Applied statisticians sometimes prefer effect sizes to raw effects, such as the median, because it is scalefree. Inference regarding the median itself has already been thoroughly investigated by a number of authors, including (McKean and Schrader (1984) and Sheather and McKean 1987). More generally, the problem of Studentizing a quantile estimator has been studied by (Bloch and Gastwirth 1968;Hall andSheather 1988 andSiddiqui 1960), amongst others.We are given a location-scale family F α,β (x) = F ((x − α)/β) where α, β > 0 are unknown. Assume F = F 0,1 has a continuous derivative f which is symmetric about 0 and is positive over a possibly infinite symmetric interval containing 0. Denote the quantile function of F by G = F −1 , its value at any 0 < r < 1 by x r = G(r), and its derivative at r by g(r) = {f (x r )} −1 . The rth quantile of F α,β is related to x r of F by α + βx r , and g α,β (r) = β g(r).For 0 < r < 0.5, a value to be chosen later, let the rth IQR of F α,β be β IQR r , where IQR r = x 1−r − x r . Also define the rth standardized median of F α,β by:th order statistic of a sample of size n from F . Let M = X ([n/2]) be the sample median, which is consistent for x 0.5 and for a fixed 0 < r < 1/2 define the rth sample IQR by, which is a consistent estimator of x 1−r − x r . We want to estimate the rth standardized median defined in (22.1) byδ r = M/R r . In the next Sect. 22.2 we derive a variance stabilizing transformation (VST) ofδ r . This leads to confidence intervals for δ r , whose effectiveness of coverage is evaluated R. G. Staudte ( )