Hi,
I am learning to use your gsDesign package!?I have a question about Pocock and OBF boundary. As far as Iunderstand, these 2 boundaries require equal spacing between interim analyses(maybe this is not correct?). But I can still use gsDesign to run an analysisbased on unequal spacing:?gsDesign(k=2,test.type=2,timing=c(0.75,1),alpha=0.05,sfu='Pocock')Symmetrictwo-sided group sequential design with90 %power and 5 % Type I Error.Spendingcomputations assume trial stops if a bound is crossed.???????????Sample???????????Size ??AnalysisRatio*? Z?? Nominal p? Spend????????1? 0.796 1.82??? 0.0346 0.0346????????2? 1.061 1.82??? 0.0346 0.0154????Total??????????????????????0.0500 ?++alpha spending:Pocockboundary.*Sample size ratio compared to fixed design with no interim?Can anyone share some light whether the above analysis is stillvalid? Or for unequal spacing, I have to use Lan-Demet?s error spendingfunction approximations??Thank you,