Modeled and empirical within classroom FRI attack rates within schools for four different hierarchical models. Classes were sorted first by schools (PS1–3 are primary schools, SS1–3 are secondary schools, indicated by families of colors), then by age group of the class (indicated by different shades of color) and then randomly within age groups. Point estimates (colored dots) are posterior means, while colored lines indicate 95% uncertainty intervals. Empirical proportions are indicated by crosses. The full model contains age, class and school effects; the other models ignore one of these three effects.