[R-sig-ME] How can I estimate deviance explained of a mixed gamm?

[Jon Lopez]

Dear mixed modelers,

I have already asked about this issue but never recived an answer
back. So I will try again.
I have been modelling fish biomass according to some environmental
parameters using mixed
effect models (gamm4 package). I don't want to bore you with the
details of my models since
I believe that they are not significant to the point of this message.
However, please feel
free to ask me about anything in case you think it is important. I
have some GAMM
candidates already. I am able to get AIC, BIC, R-sq, ... scores for
these models but,
unfortunately, I can't obtain deviance explained from them.

I have found an interesting procedure to try to derive it, published by
Gilman and colleagues in 2012. Here is the complete reference in case any
of you want to take a look to it:

"Gilman, E., Chaloupka, M., Read, A., Dalzell, P., Holetschek, J., Curtice,
C., 2012. Hawaii longline tuna fishery temporal trends in standardized
catch rates and length distributions and effects on pelagic and seamount
ecosystems. Aquatic Conservation: Marine and Freshwater Ecosystems 22(4),
446-488."

Nevertheless, the procedure explained in the paper above do not provide us
with the exact score. Thus, I have been considering other options like
using the deviance explained of a equivalent GAM with the random effect as
a spline term [s(x, bs="re")] but I don't know how accurate it would be.

Do you think both options can be used as an approximation for the
GAMM's deviance
explained? What are your feelings on that?

Any suggestion would be appreciated,

Thousands of thanks,

Jon Lopez

---------------------------------
PhD candidate
AZTI-Tecnalia, Spain

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