You can use the Method tab to specify aspects of the generalized linear model such as the response distribution and the link function. (See Figure 24.8.)

The Method tab contains the following UI controls:

Response distribution

specifies the distribution of the response variable. This list corresponds to the DIST= option in the MODEL statement.

Predict probability of

specifies whether to model the probability of the first or last level of the response variable. This list is available only when the response distribution is binomial or multinomial. This list corresponds to the DESCENDING option in the PROC GENMOD statement.

Link function

specifies the link function. This list corresponds to the LINK= option in the MODEL statement.

The following table specifies the default link function for each response distribution.

Table 24.1 Default Link Functions

Distribution	Default Link Function
Binomial	Logit
Gamma	Inverse (power(–1))
Inverse gaussian	Inverse squared (power(–2))
Multinomial	Cumulative logit
Negative binomial	Log
Normal	Identity
Poisson	Log

When the choice of response distribution is multinomial, the choice of link functions is limited to the cumulative logit, the cumulative probit, and the cumulative complementary log-log.

Power

specifies the number to use for a power link function. This list is available only when the link function is the power function.

Order response by

specifies how to order the response variable. This list corresponds to the RORDER= option in the PROC GENMOD statement.

Classification variables parameterization

specifies the parameterization method for the classification variables. This list corresponds to the PARAM= option in the CLASS statement. The dialog box supports the GLM, effect, and reference coding schemes.

Estimate scale parameter as

specifies the method for estimating the dispersion parameter. This list corresponds to the SCALE= option in the MODEL statement.