RE: Model building question

From: "Steve Duffull" sduffull@pharmacy.uq.edu.au Subject: RE: [NMusers] Model building question Date: Tue, March 1, 2005 6:30 pm Hi Janet I think that you raise a key issue about the predictive performance of the model. It would seem to me (IMHO) that models developed from a different model building order but ultimately ending up to be of a similar global level of complexity, and therefore flexibility, would probably describe the data that were used to generate the model equivalently well. The prediction question (at least in my mind) is really about how well the inference from the model translates to new data which has arisen under different experimental conditions with most likely a different underlying distribution of covariates. In this case, it is possible that different models may predict quite differently - and therefore the order of model building may play a significant role for future inference. Regards Steve ========================================Stephen Duffull School of Pharmacy University of Queensland Brisbane 4072 Australia Tel +61 7 3365 8808 Fax +61 7 3365 1688 University Provider Number: 00025B Email: sduffull@pharmacy.uq.edu.au www: http://www.uq.edu.au/pharmacy/sduffull/duffull.htm PFIM: http://www.uq.edu.au/pharmacy/sduffull/pfim.htm MCMC PK example: http://www.uq.edu.au/pharmacy/sduffull/MCMC_eg.htm