February, 2003
© 2000, 2001, 2003 Scott S. Emerson, M.D., Ph.D.
Luckily,
there is rarely a need to assume a parametric model
E.g.,
methods derived from normal theory are usually
distribution free tests in large samples
It should
also be noted that many semiparametric tests are quite sensitive to an
unrealistic assumption
·E.g.,
proportional hazards models for survival data over long periods of
time
Qualification:
Distribution free Bayesian methods are not as well established
(but we’re working on it: Coarsened Bayes)