Thanks Gang,

This is going to get confusing in terms of what you and I are really talking about. We only have 3 subjects (monkeys), that's why we need to run multiple sessions / subject. I think I have to turn the scripting upside down a little to get it to work for this scenario, follow me through...

My columns are really:

Session Monkey Taste Hydration InputFile

Session is the random factor. But in your terminology, it sounds like I must put it in the first column and call it 'Subj', correct? Fine.

So now I have:

Subj Monkey Taste Hydration InputFile

First, in this terminology, I want to specify Session (but remember here we're calling it 'Subj') nested in Monkey.

Is that Monkey|Session or Session|Monkey?

Second, I think I should include Monkey as a fixed effect (since monkey is really not the same as your 'Subj' (your 'Subj' is my session)):

'Monkey*Taste*Hydration'

I think you dropped Subj (i.e.session) from the fixed effects line because you thought it was in fact subject (but it's really session).


So in the end we have:

fixed effects: monkey, taste, and hydration
random effects: session (which we'll name 'Subj' in your terminology) nested in monkey

Any less confused?!

Thanks, Peter