Hi,
I know this question has been asked before but I have not seen an answer
pertaining to repeated measures anovas.
I got a simple data set with two factors: block (3 levels) and prime (2
levels). The dataset (expData) are stuctured so one column (block) states
which block a trial is in and one column (prime) states which prime was
used in the trial, another column (RT) states reation time for that trial
and finally a column (subject) states subject number (there are 10 trials
in each condition and 30 subjects so the dataset consists of 1800 obs of 4
variables).
I tried doing this repeated-measures ANOVA in SPSS which results in a
F-value of 25 for factor block and F-value 43 for factor prime.
I then try to reproduce this result in R. First I factor block and prime so
that R knows these are factors and not continous variables.
My anova command in R is aov(expData$RT ~ block * prime +
Error(expData$subject /(block * prime))
This gives me a very different result, F-values for block is 2.9 and
F-value for prime is 5.7.
I think this difference is caused by the "type" of Sum of squares test used
in SPSS and R. So, I want to use type 3 test in R.
Is this correct and how do I apply this change in type? The aov function
does not take any type arguments.
Much appreciated.
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