February, 2003
© 2000, 2001
Scott S. Emerson, M.D., Ph.D.
Session 2: 105
Error Spending Family
Lan and DeMets (1983)
approach
At each
analysis, some of the type I error is `used up’
Describe a
stopping rule according to the proportion of aU, aL used at each analysis
·General
case: alpha used by the j-th analysis determined by some function
of the proportion of maximal information available
