CASE STUDY: The Ice Cream Study at Penn State
Penn State University is world famous for its ice cream! Researchers are constantly trying to determine exactly what is most appealing to customers. A study was conducted that focused on what the optimum amount of 'fat' to
have in ice cream. So, they made batches of ice cream with fat content ranging from 0.00 to 0.28 . They randomly had 493 subjects participate in tasting and rating the ice cream, on a scale of 1 (didn't like at all) to 9 (yum yum!), with about 60 or so subjects per fat level. Thus, the response variable is polytomous (9 possible values, on an ordinal scale) and there was one independent variable--fat level, with values 0.00, 0.04, 0.08, ... , 0.28.
Dr. Harkness will give you the inside 'scoop' on what this study is about and where it came from. (pun intended!)
The relevant SAS programs and their outputs can be found below:
For R code see, ice_cream.R