# Individual level random effect for over dispersion

In glms we can use a quassipoison fudge factor to account for over dispersion in our poisson models.

In glmms we can add an individual level random effect (e.g. id) for each row in data.frame to account for over dispersion. i.e.

glmer(y ~ x + (1|group) + (1|id), family = poisson)


Can someone give me a feel for how this individual level random effect deals with over dispersion?

• have you read the material about overdispersion and observation-level random effects at http://glmm.wikidot.com/faq ? Nov 20, 2014 at 0:29