[R-sig-eco] Corrected AIC for binary response variables? (Landis, R Matthew)
Murray Efford
murray.efford at otago.ac.nz
Fri Dec 19 21:08:43 CET 2008
Matt Landis asked
>>I'm using logistic regression to investigate mortality of trees. I'm using AIC to compare models, and I'm wondering if I should use AICc instead of AIC. Burnham and Anderson [1] recommend using AICc when n/K < 40. But what do I consider for n? The logistic regression is based on 2811 observations (334 trees observed annually for <= 10 yr), but I've only observed 32 deaths. Harrell [2] would consider 32 to be the "limiting sample size" for determining the feasible number of predictor variables. Is AIC the same? Should I use 2811, 334, or 32 to figure out AICc?
You may be interested in an exchange on this topic that I initiated on www.phidot.org/forum MARK Statistics & analysis help on 30 September. I found the outcome quite unsatisfactory, and it seems the experts don't know. 334 seems safe to me, and of course it will make little numerical difference.
Murray Efford
[I'm sorry that I have this through the Digest & my reply may not conform]
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