Categorical Data Analysis Using The SAS® System, 2nd Edition

1.2. Scale of Measurement

The scale of measurement of a categorical response variable is a key element in choosing an appropriate analysis strategy. By taking advantage of the methodologies available for the particular scale of measurement, you can choose a well-targeted strategy. If you do not take the scale of measurement into account, you may choose an inappropriate strategy that could lead to erroneous conclusions. Recognizing the scale of measurement and using it properly are very important in categorical data analysis.

Categorical response variables can be

• dichotomous

• ordinal

• nominal

• discrete counts

• grouped survival times

Dichotomous responses are those that have two possible outcomes—most often they are yes and no. Did the subject develop ...