Dear Nick,
> I am analysing brain PET data and I get the same results when I apply
> Grand Mean
> Scaling and when I don't apply it.
> What does this mean and how can I control application of Grand Mean
> Scaling?
I'm citing Andrew Holmes here. He helpfully put some explanation in the
spm_spm_ui.m file:
Grand mean scaling : Scaling of the overall grand mean simply
scales all the data by a common factor such that the mean of all the
global values is the value specified. For qualitative data, this puts
the data into an intuitively accessible scale without altering the
statistics.
Stefan
--
Stefan Kiebel
Functional Imaging Laboratory
Wellcome Dept. of Cognitive Neurology
12 Queen Square
WC1N 3BG London, UK
Tel.: +44-(0)20-7833-7478
FAX : -7813-1420
email: [log in to unmask]
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