The AICs do not seem right to me either. Unless I am missing something, it
appears that the formula:
AIC= -2x logLik -2k
is being applied, rather than:
AIC= -2x logLik +2k
Meaning models with fewer degrees of freedom are being penalised.
So in your example I make the degrees of freedom
9.61
I think I've figured it out, the AIC column is the IMPROVEMENT in AIC
compared to the null model. So bigger values are better.
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Indeed! That is what was confusing me too. Glad you figured it out.
-Teresa
On Wed, Sep 22, 2010 at 7:31 AM, whoppitt [via R]
ml-node+2550409-1571116512-138...@n4.nabble.comml-node%2b2550409-1571116512-138...@n4.nabble.com
wrote:
I think I've figured it out, the AIC column is the IMPROVEMENT
You noticed that the AIC increases while the p-value decreases as you
change the model and hold the data fixed. There would be more indication
of a problem if you instead noticed the same relationship between the
AIC and the p-value as you changed the data and held the model fixed.
David
Hi,
I am new to R and AIC scores but what I get from coxme seems wrong. The AIC
score increases as p-values decrease.
Since lower AIC scores mean better models and lower p-values mean stronger
effects or differences then shouldn't they change in the same direction? I
found this happens with the
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