Researchers are often interested in performing regression when the response variable is categorical.
Logistic regression may be used when the response variable has only two categories. When the response variable has more than two categories, methods that extend the technique of logistic regression are available. The choice of method depends on whether the response variable is measured on an ordinal or nominal scale. This newsletter gives examples of nominal and ordinal response variables and describes techniques that can be used to analyze these kinds of data. A nominal scale has categories that are not ordered.