Modeling and Multivariate Methods - SAS

Chapter 7
Performing Logistic Regression on Nominal and
Ordinal Responses
Using the Fit Model Platform
For nominal response variables, the Fit Model platform fits a linear model to a multi-level logistic response
function using maximum likelihood. Likelihood-ratio statistics and Lack of Fit tests are computed for the
whole model. Likelihood-ratio tests and Wald tests can be computed for each effect in the model. When the
response is binary, odds ratios (with confidence intervals) are available.
For ordinal response variables, the Fit Model platform fits the cumulative response probabilities to the
logistic distribution function of a linear model using maximum likelihood. Likelihood-ratio test statistics are
provided for the whole model and lack of fit.
For simple main effects, you can use the Fit Y by X platform to see a cumulative logistic probability plot for
each effect. See Basic Analysis and Graphing.