“…We were assured, however, of future considerations, at least as the 'gold standard', for the upcoming dose ranging trials. In addition to estimating the model parameters of the underlying dose response curve (Kalish, 1990;Meier et al, 1993;Zeng and Zhu, 1997;Zhu and Wong, 2000), there is also a great need to estimate other percentiles besides the median effective dose (α) (Flournoy, 1993;Rosenberger and Grill, 1997;Mats et al, 1997;Zhu and Wong, 2001). For example, the low percentiles are of interest in toxicity studies such as in virtually safe dose extrapolation problems, and the high percentiles are of interest in efficacy studies.…”