The wine
dataset adopted from Randall(1989),
represents the outcome of a factorial experiment on factors
determining the bitterness of wine. Two treatment factors
(temperature and contact) with two levels each are provided,
with the rating of wine taken on a continuous scale in the interval
from 0 (none) to 100 (intense). These were subsequently grouped
into five ordered categories ranging from 1 = 'least bitter'
to 5 = 'most bitter'. Altogether, nine different judges assessed
wine from two bottles and out of the four treatment conditions,
making a total of 72 observations.