0.00 0.25 0.50 0.75 1.00 −4 −2 0 2 4 6 P(Reject H 01 | 1  =  2  =  3  =  ) Design Delta = −0.25 Delta = 0 Delta = 0.25 Delta = 0.50 L = 1 0.00 0.25 0.50 0.75 1.00 −4 −2 0 2 4 6 P(Reject H 0d  for some d  | 1  =  2  =  3  =  ) Design Delta = −0.25 Delta = 0 Delta = 0.25 Delta = 0.50 L = 1 Figure 2: Power Curves. Power curves of the single-stage ( L = 1) and considered group sequential designs across a range of values of the true response rate in the experimental treatment arms θ . 14