Past exam of the mathematics course of the University of Cambridge / 2026 / iii / Paper 218 / 1 / d

For response $j$ from subject $s$, model2 is the generalized linear mixed modelwith conditional independence given the random intercepts. The fitted values are ${\hat{\beta }}_0=8.9966$, ${\hat{\beta }}_1=-1.2317$, ${\hat{\tau }}^2=1.7533$, and fitted residual dispersion $0.7591$.

The random intercept models persistent between-subject differences and the resulting within-subject dependence among repeated measurements. That is the main feature absent from model1.