Saturated model

Topic of Paired comparisons, and how far a fit is from the data, part of Generalised linear models

Saturated model

Type Topic
Taught in Paired comparisons, and how far a fit is from the data
Part Generalised linear models
Questions using it 3

A model with one parameter per observation, so that its fitted means equal the data. It fits perfectly and predicts nothing; the deviance of any other model is measured from it.

In Paired comparisons, and how far a fit is from the data

McCullagh and Nelder’s sentence is the right one: fitting a model replaces the data y_1,\ldots,y_n by fitted means \hat\mu_1,\ldots,\hat\mu_n that depend on fewer parameters than there are observations. A model with n parameters can repeat the sample exactly and then cannot predict anything else. The saturated fit is the baseline you compare with, not the fit you report.

Used in

See also

Deviance · Residual deviance · Null deviance · Scaled deviance · Deviance residual · Bradley–Terry model · Three links, one cholesterol slope · Analysis of deviance · Residuals in a GLM

Glossary and index