64
Adaptive Sampling: The Price
Adaptive sampling plans are less
efficient
•Tsiatis
& Mehta (2002)
–A
classic prespecified group sequential stopping rule can be found
that is more efficient than a given adaptive design
•Shi
& Emerson (2003)
–Fisher’s
test statistic in the self-designing trial provides markedly less
precise inference than that based on the MLE
•To
compute the sampling distribution of the latter, the sampling
plan must be known