[R] poisson regression nested effects
csillery at selway.umt.edu
Sat Jul 12 23:51:10 CEST 2003
I have two treatment levels and multinomial behaviors as response
and also a covariate (size). The individuals were split to the two
treatment levels on the first day and switched on the second day.
I am interested not only the treatmen effect but the effect of the day,
such that the individuals experinced treatment 1 first, or treatment 2
I conditioned on the most frequent behavior and than run separate poisson
models on the rest of the behaviors (proportions of time when they did a
behavior given that they do not do the most frequent).
glm(behav1~treatment*day+size, family=poisson(), data=data)
I wonder that it is not correct because the day effect is nested in the
treatment effect but I do not know how set it up in glm().
Also do I need to do any corrections because of the separate tests on
each beahvior? It is more a statistical question.
Thanks for any help in advance!
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