Norton and Dunn (1985) compiled data from four family practice clinics in Toronto to quantify the association between snoring and heart disease for 2484 subjects.
data(snore)
A data frame with 2484 observations on the following 3 variables.
snoring
A factor with levels every.night
nearly.ever.night
never
occasional
ord.snoring
Agresti (21012) transformed the explanatory levels to ordinal values in his analysis of this data.
disease
Presence/absence of heart disease