search for: txbait

...iate nesting syntax in the model we are running (as gleaned from Venables and Ripley 1999, 3rd edition), with stations being nested within sites. To provide an example of the syntax, the full model with which we began is: TXa <- coxph(Surv(dt, status)~site/station+foodtype*foodsize+vpd, data=TXbait) This obviously generates a large number of terms, even as we work down to the reduced model. Is this syntax testing what we think it is testing, i.e. are we controlling for station effects in our results? Are there potential problems with our approach to the analysis of which we should be awar...