Dear SPM experts
In SPM5 there is the opportunity to design an interaction between a factor
and a covariate. There are several centering options for that. Question:
"Overall mean" means that the covariate is centered on the mean of the whole
factor (across factor levels) with which the covariate interacts, right?
In contrast, "Factor 1 mean" means that the covariate is centered on the
mean of the first level of the factor with which the covariate interacts,
rather wrong, or?
Thanks for clarification
Best regards
Juergen
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Juergen Haenggi
Ph.D. (Dr. des.)
Division of Neuropsychology
Institute of Psychology
University of Zurich
Binzmuehlestrasse 14, PO Box 25
8050 Zurich, Switzerland
0041 44 635 73 97 (phone office)
0041 76 445 86 84 (phone mobile)
0041 44 635 74 09 (fax office)
BIN 4.D.04 (office room number)
[log in to unmask] (email)
http://www.psychologie.uzh.ch/neuropsy/ (website)
http://www.juergenhaenggi.ch (private website)
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