Re: Please help with the design: 22 parameters influencing single outcome

Why in hell didn't you consult with a real statistician before you 
designed your experiment?

Pawel Kusmierek wrote:

> I would appreciate your advice on statistical design.
>
> There are four subjects, each was tested with 171 stimuli. Each
> stimulus is described by 22 parameters. A test yields a single
> numerical outcome. I am interested whether the parameters of stimuli
> influenced test results.
>
> One idea is to average the subjects' test results for each stimulus
> and calculate partial correlation coefficients between the average
> test result and the 22 parameters.  However, this approach offers no
> view into the intersubject variability.
>
> Another idea is to categorize the stimuli according to each
> parameter's value: e.g. >=median vs. <median.  Then I would check
> whether test results obtained with stimuli which have high (>=median)
> parameter values differ from test results obtained with stimuli which
> have low (<median) values.
>
> I was thinking of a 23-factor ANOVA, with one repeated mesures factor
> (subject) and 22 factors=parameters.  In the design, only main factors
> and interactions (subject x a_parameter) would be analyzed.
>
> In such way, I would get a measure of whether any of the parameters
> influences the test result (high Fs for 22 factors-parameters) and a
> measure of across-subjets consistency of this influence (low Fs for
> subject x parameter).
>
> I would like to see your comments.
>