If you want to test for an interaction between continuous variables, then you should create a new regressor by multiplying them together then test that regressor doug
On 08/22/2013 08:09 AM, Jacobs H (NP) wrote:
Hi all,
I my manuscript, I examined the association between cognition and cortical thickness. I first did this in three groups separately and then ran a F-test. One of the reviewers, now wants me to examine the interaction between cognition and education (all continuous).
Would this be the correct contrast for each group separately (last two zeros are for covariates, also continuous)
0 1 -1 0 0
Would this be the correct way for the F-test:
0 0 0 0 0 1 -1 0 -1 1 0 0 0 0 0 0 0 0 0 0 1 0 -1 -1 0 1 0 0 0 0 0 0
Thanks!
Heidi
================================================ Dr. Heidi Jacobs Postdoc researcher Faculty of Health, Medicine and Life Sciences School for Mental Health and Neurosciences Division Cognitive Neuropsychiatry and Clinical Neurosciences Alzheimer Center Limburg h.jacobs@maastrichtuniversity.nl www.maastrichtuniversity.nl www.heidijacobs.nl
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