#### the data file cheese.dat is needed for this R program
#### see the course web site
cheese <- read.table( "cheese.dat", col.names=c("Cheese", "Response", "N") )
#### see if Response is a factor
is.factor( cheese$Response )
#### make it into an ordered factor
cheese$Response <- factor( cheese$Response, ordered=T )
#### load the MASS package
library(MASS)
#### fit the proportional-odds logistic regression model
result <- polr( Response ~ Cheese, weights=N, data=cheese )
summary(result)