Figure 1: as a function of σa0 under the Ibrahim and Chen (IC) power prior for a normal model with unknown mean and known variance. Current data sample sizes are (a) n = 1, (b) n = 2, (c) n = 10 and (d) n = 100. Each plot presents trends when the historical sample size (n0) is infl ated by factors of 1 (solid), 2 (dashed) and 5 (dotted). In each plot, identical observations were used for both D and D0 (replicates were used to infl ate D0). U [0,1] corresponds to the value 0.2887, the standard deviation for a uniform (0,1) random variable. As the fi gures indicate, for n = 10,decreases as σa0 increases, effectively excluding D0.