David.
On Jan 9, 2011, at 7:10 AM, Frodo Jedi wrote:
> Dear all,
> how can I perform a post hoc analysis for ANOVA with repeated
> measures (in
> presence of a balanced design)?
> I am not able to find a good example over internet in R...is there
> among you
> someone so kind to give
> me an hint with a R example please?
>
> For example, the aov result of my analysis says that there is a
> statistical
> difference between stimuli (there are 7 different stimuli).
> ...I would like to know which stimuli are involved.
>
>> aov1 = aov(response ~ stimulus*condition + Error(subject/
>> (stimulus*condition)),
>> data=scrd)
>> summary(aov1)
>
> Error: subject
> Df Sum Sq Mean Sq F value Pr(>F)
> Residuals 14 227.57 16.255
>
> Error: subject:stimulus
> Df Sum Sq Mean Sq F value Pr(>F)
> stimulus 6 11.695 1.94921 2.3009 0.04179 *
> Residuals 84 71.162 0.84717
> ---
> Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
>
> Error: subject:condition
> Df Sum Sq Mean Sq F value Pr(>F)
> condition 1 42.076 42.076 12.403 0.003386 **
> Residuals 14 47.495 3.393
> ---
> Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
>
> Error: subject:stimulus:condition
> Df Sum Sq Mean Sq F value Pr(>F)
> stimulus:condition 6 9.124 1.5206 1.4465 0.2068
> Residuals 84 88.305 1.0513
>>
>
>
>
> In attachment you find the table I am using, you can access it by
> means of:
> scrd<-
> read.csv(file='/Users/....../tables_for_R/
> table_quality_gravel.csv',sep=',',header=T)
>
>
> The data are from an experiment where participants had to evaluate
> on a seven
> point likert scale
> the realism of some stimuli, which are presented both in condition
> "A" and in
> condition "AH".
>
>
> Thanks in advance
>
> Best regards
>
>
> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.
David Winsemius, MD
West Hartford, CT