[R] error terms in mixed ANOVA's
John Christie
jc at or.psychology.dal.ca
Fri Jun 27 23:26:15 CEST 2003
Hi,
Newbie here, just joined the list.
I discovered something interesting when performing a mixed between and
within (repeated measure) ANOVA in R. The error terms (SS actually I
guess) are inflated by the number of factors of the within measure.
This just seems wrong. I think I'm doing it right
e. g.
subj grp test x
1 1 1 ...
1 1 1
1 1 2
1 1 2
2 2 1
2 2 1
2 2 2
2 2 2
So, the anova is done with
aov (x~ grp*test + Error(subj/test))
Is there something I am doing wrong here? On a related note can I
properly analyze a subset of between measures by adding something to my
aov command instead of aggregating the data?
thanks
John
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