Re: GLM vs unbalanced designs

[Jason Stover]

On Sat, Nov 12, 2011 at 08:22:00AM +0000, John Darrington wrote:
> I've been reading a bit about two way anova with unbalanced designs.
> 
> I concluded that we should have been using what the literature calls 
> "effects coding" http://www.ats.ucla.edu/stat/mult_pkg/faq/general/effect.htm
> instead of "dummy coding" 
> http://www.ats.ucla.edu/stat/mult_pkg/faq/general/dummy.htm which is what we 
> have been using until now.
> 
> However I tried hacking up a quick change to use "effects coding", but 
> unfortunately it didn't improve anything.
> 
> Am I barking up the wrong tree here?

Could be. I started thinking about this again recently, and I suspect
the problem has to do with weights for unbalanced designs. The
"effects coding" may address this.

I'll look around more and let you know what I find.

-Jason