February, 2003
© 2000, 2001
Scott S. Emerson, M.D., Ph.D.
Boundary shape
functions
Pj measures the proportion of information
accrued at the j-th analysis
·often Pj = Nj / NJ
·
Boundary
shape function f(Pj) is a monotonic function used to relate
the dependence of boundaries at successive analyses on the information
accrued to the study at that analysis