Covariate or Random Factor?

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jsh

Covariate or Random Factor?

Postby jsh » Fri Jul 11, 2008 5:02 pm

Hi all,

I am doing 2-way ANOVA and I can't decide if one of my variables should be a covariate or a random factor. I want to see if there is a site effect on my outcome. I have been happily plugging along using SiteID as a covariate but now it is occurring to me that maybe it should be a random factor instead. Thought I would get an outside opinion or two before I redo all my stats :)

Thanks
Curren
Posts: 1
Joined: Thu Sep 18, 2008 6:38 pm

Postby Curren » Thu Sep 18, 2008 6:57 pm

I would think this depends on whether it is a catagorical or continuous variable. In SPSS, 'factor' refers to catagorical variables and covariate refers to continuous variables. It sounds like yours is catagorical (so factor) from the name.

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