Hi,
l am attempting to analyse data for an interlab study with a mixed model, its a nested design with 5 variables, the dependant variable is titers, the structure of my analysis is as follows
Fixed Effect
Sample (30 of)
Random Effects
Sample*Lab (3 levels)
Sample*Day (3 Levels)
Sample*Run (2 Levels)
Replicate[Sample,Lab,Day,Run] (replicate has 2 levels)
Sample*Lab*Day
l get the error message that Replicate[Sample,Lab,Day,Run] confounds with residual, this is the first time i have encountered this message and i am not sure what its telling me, has anyone encountered this before and how did they overcome it??
Thanks
Mick