My research focuses on the
applied uses of computationally intensive methods in statistics. One
area in which computaional power is particularly useful is in the use
of Monte Carlo approximations which can replace intractable calculations
or asymptotic argeuments. The use of these methods, however, require
reliable software and good diagnostics for when there may be problems
with the underling assumptions. In my doctoral work I examined diagnostics
for Markov chain Monte Carlo methods which are particularly important
in Bayesian statistics. Since then I have worked on the bootstrap and
other resampling methods. A suite of functions that I have developed
to implement many of these methods is used worldwide. These functions
allow for the application of resampling methods in many fields. Much
remains to be done, however. I am currently working on applied graphical
diagnostics for bootstrap failure. I am also examining new areas of
application for these methods and improvements on existing methods.
My latest area of research is in Monte Carlo implementations of the
EM algorithm for likelihood inference when more standard methods cannot
be used.