Modeling and Multivariate Methods - SAS

Chapter 16 Performing Choice Modeling 431
Transforming Data
Figure 16.38 Fit Model Nominal Logistic Regression Results for the Cancer Data
Notice that the likelihood ratio chi-square test for Smoker*Lung Cancer in the Choice model matches the
likelihood ratio chi-square test for Smoker in the Logistic model. The reports shown in Figure 16.37 and
Figure 16.38 support the conclusion that smoking has a strong effect on developing lung cancer. See the
“Performing Logistic Regression on Nominal and Ordinal Responses” chapter on page 197 for details.
Transforming Data
Transforming Data to Two Analysis Tables
Although data are often in the Response/Profile/Subject form, the data are sometimes specified in another
format that must be manipulated into the normalized form needed for choice analysis. For example,
consider the data from Daganzo, found in Daganzo Trip.jmp. This data set contains the travel time for three
transportation alternatives and the preferred transportation alternative for each subject. A partial listing of
the data set is shown in Figure 16.39.