Message-ID: <95C27F38DEEDE840829942CC05435F8F0C1C2109@rex4.intranet.epfl.ch>
Date: 2008-03-27T12:05:25Z
From: Aberg Carl
Subject: Covariates in LME
Hi,
Im using lme to calculate a mixed factors ANOVA according to:
px_anova = anova(lme(dep~music*time*group, random = ~1|id, data = px_data))
where
dep is a threshold,
time is a repeated measures variable (2 levels)
group is a between subjects variable (2 levels)
id is a random factor (subject id)
music is a between subjects variable (2 levels) indicating if a person has a musical experience, or not
Musical experience is now decided by categorizing depending on the number of years practicing playing an instrument.
I would like to use the years of playing an instrument as a covariate instead of creating categories.
How can I do this in a simple way?
Thanks and have a nice day!
Kristoffer