Re: FW: Rejected posting to ASREML-L@AGRIC.NSW.GOV.AU

From: Arthur Gilmour <arthur.gilmour_at_AGRIC.NSW.GOV.AU>
Date: Thu, 24 Feb 2005 11:16:38 +1100

Dear Bart,

I tried to run a binomial model in ASREML, but got the surprising message
that LogL is unsuitable for comparing GLMs. I know about the complexity of
analysing binomial models, but I was unaware of the fact that 'the
situation was that bad'. Is there any reference to this? And does this
mean that it is no longer possible to run binomial models in ASREML?

The LogL value reported by ASReml is for the analysis of the working
As this working variable changes between iterations and especially between
the LogL values are not comparable - even to confirm convergence of a
particular model.

ASReml also calculates a 'Variance heterogenity factor' which is the
where Deviance is calculated for the underlying Maximum likelihooh model.

In a GLM, (no random effects), this deviance can be used to compare
However, for GLMM (with random effects), it does not represent the total
(ignoring part related to the random effects). So it also is unsuitable
as a basis
for testing in GLMM models.

Note that the GLMM procedures in ASReml are also seriously biassed when
to Animal models (which is why they have not been described in the User

Best wishes in the Name of Jesus Christ, my Saviour.
Check out my 'CargoVale' website (see below)

Arthur Gilmour PhD
Principal Research Scientist (Biometrics)
NSW Department of Primary Industries
Orange Agricultural Institute, Forest Rd, ORANGE, 2800, AUSTRALIA
fax: 02 6391 3899; 02 6391 3922 Australia +61
telephone work: 02 6391 3815; home: 02 6364 3288;
The ASReml discussion group
   has reactivated. To join,

Movements: 6-11 Feb Biometrics meeting at Thredbo
  14-18 Feb Armidale Summer School

This message is intended for the addressee named and may contain
confidential information. If you are not the intended recipient or
received it in error, please delete the message and notify sender. Views
expressed are those of the individual sender and are not necessarily the
views of their organisation.
Received on Wed Feb 24 2005 - 11:16:38 EST

This webpage is part of the ASReml-l discussion list archives 2004-2010. More information on ASReml can be found at the VSN website. This discussion list is now deprecated - please use the VSN forum for discussion on ASReml. (These online archives were generated using the hypermail package.)