interpreting Std. error from glmer output
Well, it depends. It depends on what you mean by deviance, you should clarify this (here is a start http://en.wikipedia.org/wiki/Deviance_%28statistics%29). In general, deviance is used as a measure of model fit and usually encountered as a component of Information criteria. Do you need to take the uncertainty (SE) in model estimates into account? It is probably a good idea if you are going to make predictions based on model estimates to also calculate predictions at the 95CI limits.
On 15/09/2009, at 10:26 PM, Christine Griffiths wrote:
Thank you. So to clarify, I do not need to calculate the deviance of the standard error from the intercept standard error, in the way that I would do for the estimate? Cheers Christine --On 15 September 2009 21:38 +1000 Will Morris <wkmor1 at gmail.com> wrote:
The SE is a measure of the models uncertainty about the parameter
estimates, it takes into account your sample size as well as sample
variance. +_2*SE is usually a good estimate of the 95% confidence
interval. In other words your treatment effect for treatment2 is
probably somewhere between -.6 and -.86.
On Tue, Sep 15, 2009 at 8:05 PM, Christine Griffiths
<Christine.Griffiths at bristol.ac.uk> wrote:
I want to plot my predictions from a model and use the standard error
output as a measure of dispersion as I am unable to calculate
confidence
intervals with mcmcsamp as I have a binomial distribution.
I know that the estimates are deviations from the intercept.
Fixed effects below:
Estimate Std. Error z value Pr(>|z|)
(Intercept) 2.90836 0.34041 8.544 < 2e-16 ***
treatment2 -0.73507 0.12986 -5.660
1.51e-08
***
treatment3 -1.20052 0.12371 -9.705 < 2e-16 ***
So the estimate for treatment 2 is 2.9 + -0.73. Are standard errors
also
deviations from the intercept? i.e. 0.34 + 0.13 for treatment 2?
Many thanks
Christine
_______________________________________________ R-sig-mixed-models at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models -- Will Morris Masters of Philosophy candidate Vesk Plant Ecology Lab The School of Botany The University of Melbourne Australia Phone: +61 3 8344 0120 http://www.botany.unimelb.edu.au/vesk/
---------------------- Christine Griffiths PhD student School of Biological Sciences University of Bristol Woodland Road Bristol BS8 1UG Tel: 0117 9287593 Fax 0117 3317985 Christine.Griffiths at bristol.ac.uk http://www.bio.bris.ac.uk/research/mammal/tortoises.html
Will Morris Masters of Philosophy candidate Vesk Plant Ecology Lab The School of Botany The University of Melbourne Australia Phone: +61 3 8344 0120 http://www.botany.unimelb.edu.au/vesk/