Dear all, I have a quite simple question but I do not find a clear answer on the internet nor in books. The context : I am currently working on different aspects of bird aging. I have done animal models with MCMCglmm to find if there is an additive genetic variance (Va) in my sexual life traits. One animal model has been done by age. Now, I am interested in testing the differences in Va (posterior mode) between ages. My question : As posterior predictions are supposed to be normally distributed (if the model converge), is it possible to use multiple Student test (corrected for unequal variance and pairwise multiple comparison) to test statiscal difference on posterior prediction? It seems to me that all assumptions are meet to use Student test but maybe there some problems that I am not thinking about. If you have a more elegant way to test differences of posterior distributions, let me know! Thank in advance for reply and sorry for this beginner question. Stephane
Post-test on MCMCglmm posteriors distribution
2 messages · Stephane Chantepie, Jarrod Hadfield
1 day later
Dear Stephane, Do you mean posterior predictions or posterior distributions? If the latter, and you want to compare wether Va1 > Va2, for example, you can just use HPDinterval on the difference. Cheers, Jarrod Quoting Stephane Chantepie <chantepie at mnhn.fr> on Wed, 11 Jul 2012 16:01:53 +0200:
Dear all, I have a quite simple question but I do not find a clear answer on the internet nor in books. The context : I am currently working on different aspects of bird aging. I have done animal models with MCMCglmm to find if there is an additive genetic variance (Va) in my sexual life traits. One animal model has been done by age. Now, I am interested in testing the differences in Va (posterior mode) between ages. My question : As posterior predictions are supposed to be normally distributed (if the model converge), is it possible to use multiple Student test (corrected for unequal variance and pairwise multiple comparison) to test statiscal difference on posterior prediction? It seems to me that all assumptions are meet to use Student test but maybe there some problems that I am not thinking about. If you have a more elegant way to test differences of posterior distributions, let me know! Thank in advance for reply and sorry for this beginner question. Stephane
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