[R-sig-ME] 4 binary DVs, subjects nested within schools

Yvonnick Noel yvonnick.noel at free.fr
Wed Nov 23 09:57:40 CET 2011

> The data is like selections from a menu, where all of the above is
> possible.  This actual project is about student behaviors in the class
> room, but it seems more understandable to me to think of it as a
> person's taste for ice cream. Respondents are asked "do you like
> chocolate ice cream" or "do you like vanilla ice cream" or "strawberry
> ice cream".  So the dependent variable is multivariate like this (yes,
> no, yes, no).
> Where can I learn more about the multivariate approach to this?
> And why are multivariate approaches not making the same mistake that
> is described in this literature on comparison of coefficients across
> logit models fitted for separate groups. I mean, if the variance
> parameter is not identified, how can I meaningfully put together 4
> logit models?

What you need is a Rasch model (and by no means a multinomial model).

As to a mean of fitting this model with glmer, See:


Also, comparing slopes between groups is OK, but comparing slopes on a 
multivariate response vector is less trivial. Item response models are 
suited for that.


Yvonnick Noel
University of Brittany at Rennes
Department of Psychology
Rennes, France

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