On Wed, Jan 15, 2003 at 07:27:07PM +0100, CG Pettersson wrote: ... > How do I tell R that the Trial term should be random in the lm() statement? It´s quite obvious that the Error term in aov() is random, but in the lm()? try library(nlme) help(lme) Cheers Jason -- Indigo Industrial Controls Ltd. 64-21-343-545 jasont at indigoindustrial.co.nz