Hi.
I am trying to set up a parametric design to model different intensities of my stimuli. I
know that I should use the 3 column format for this. But do I have to transform the
values in the 3rd column?
For example, I have stimuli ranging in intensity from 0 to 100.
Do I just enter the raw values?
9.241 3.12 33
25.242 3.172 2
41.243 2.375 45
56.847 2.815 23
72.434 2.683 11
88.435 3.985 76
105.247 2.949 19
Or do I have to demean the values?
9.241 3.12 3.1428571
25.242 3.172 -27.8571429
41.243 2.375 15.1428571
56.847 2.815 -6.8571429
72.434 2.683 -18.8571429
88.435 3.985 46.1428571
105.247 2.949 -10.8571429
Or is it better to use z-scores?
9.241 3.12 0.127166212
25.242 3.172 -1.127155077
41.243 2.375 0.612709936
56.847 2.815 -0.277453559
72.434 2.683 -0.762997283
88.435 3.985 1.867031225
105.247 2.949 -0.439301467
Thanks for your help.
Cheers
Thomas
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