[R] Negative AIC

[Ben Bolker]

  If all the models are fitted to the same data set, using the same
modeling tools (you have to be careful e.g. comparing lmer models to
glm models, because they use different additive constants), and
everything seems to make sense (!!!), then yes.  I would be a little
surprised, and think that something was wrong, if you have some AIC
values that are on the order of -20,000 (as below) and others that are
+20,000 ...

  Ben Bolker

Corrado wrote:
> My worry is: can I compare negative AIC with positive AIC? does the comparison 
> still hold?
> 
> On Thursday 10 September 2009 15:57:01 Ben Bolker wrote:
>> Corrado-5 wrote:
>>> Dear R list,
>>>
>>> I just obtained a negative AIC for two models (-221.7E+4
>>>  and -230.2E+4). Is that normal?
>> It's not necessarily wrong.  See <http://emdbolker.wikidot.com/faq>
> 
> 
> 


-- 
Ben Bolker
Associate professor, Biology Dep't, Univ. of Florida
bolker at ufl.edu / www.zoology.ufl.edu/bolker
GPG key: www.zoology.ufl.edu/bolker/benbolker-publickey.asc

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