I am trying to get information about the output produced by the bounds function. Code that runs the package along with sample output is below. Questions (1) Do the values given under boundaries, lower and upper (Boundaries: Time Lower Upper Exit pr. Diff. pr. 1 0.10 -6.9913 6.9913 2.7227e-12 2.7227e-12 2 0.33 -3.7308 3.7308 1.9097e-04 1.9097e-04 3 1.00 -1.9605 1.9605 5.0000e-02 4.9809e-02) represent values of z-scores which an analysis must exceed to declare the analysis significant (after accounting for multiple looks)? (2) The Exit pr. is described in the documentation as exit.pr the vector of cumulative exit probabilities at each analysis. What is meant by "exit probabilites" (3) Diff. pr. is described in the documentation as diff.pr the vector of exit probabilities accumulated at each analysis. What is meant by "exit probabilities accumulated"? Thank you, John install.packages("ldbounds") library(ldbounds) t2 <- c(0.10,0.33,1) t2 obf.bd <- bounds(t2,iuse=c(1,1),alpha=c(0.025,0.025)) summary(obf.bd) plot(obf.bd) Lan-DeMets bounds for a given spending function n = 3 Overall alpha: 0.05 Type: Two-Sided Symmetric Bounds Lower alpha: 0.025 Upper alpha: 0.025 Spending function: O'Brien-Fleming Boundaries: Time Lower Upper Exit pr. Diff. pr. 1 0.10 -6.9913 6.9913 2.7227e-12 2.7227e-12 2 0.33 -3.7308 3.7308 1.9097e-04 1.9097e-04 3 1.00 -1.9605 1.9605 5.0000e-02 4.9809e-02 John David Sorkin M.D., Ph.D. Professor of Medicine Chief, Biostatistics and Informatics University of Maryland School of Medicine Division of Gerontology and Geriatric Medicine Baltimore VA Medical Center 10 North Greene Street GRECC (BT/18/GR) Baltimore, MD 21201-1524 (Phone) 410-605-7119 (Fax) 410-605-7913 (Please call phone number above prior to faxing) [[alternative HTML version deleted]]