February, 2003
© 2000, 2001 Scott S. Emerson, M.D., Ph.D.
Possible approaches
(cont.)
In
S+SeqTrial, all probability models have statistical information
directly proportional to sample size for block randomized experiments,
thus we chose to update V at all analyses using the current best estimate
Other
statistical packages (PEST, ?EaSt) constrain boundaries using the
estimate of statistical information available at the previous
analyses.
There is no clear
best approach