The GROUP statement signifies the beginning of a group specification block and designates a group number for the group. All subsidiary group specification statements after a GROUP statement belong in that group until another MODEL or GROUP statement is used. The subsidiary group specification statements refer to one of the following four statements:

• FREQ statement

• PARTIAL statement

• VAR statement

• WEIGHT statement

For example, consider the following statements:

proc calis; 
   var X1-X4;
   group 1 / label='Women' data=women_data;
      freq  Z;
   group 2 / label='Men' data=men_data;
      partial P;
   model 1 / group = 1-2;
      factor N=1; /* One factor exploratory factor analysis */
   run;

In the GROUP statements, two groups are defined. Group 1, labeled as 'Women', refers to the data set women_data. Group 2, labeled as 'Men', refers to the data set men_data. Both groups are fitted by an exploratory factor model defined in Model 1, as indicated in the GROUP= option of the MODEL statement. While the frequency variable Z defined in the FREQ statement is applicable only to Group 1, the partial variable P defined in the PARTIAL statement is applicable only to Group 2. However, the VAR statement, which appears before the definitions of both groups, applies globally to both Group 1 and Group 2. Therefore, variables X1–X4 are the analysis variables in the two groups.

You can set group-specific options in each GROUP statement. All but one (that is, the LABEL= option) of these options are also available in the MODEL and PROC CALIS statements. If you set these group-specific options in the PROC CALIS statement, they will apply to all groups unless you respecify them in the GROUP statement. If you set these group-specific options in the MODEL statement, they will apply to all groups that are fitted by the associated model. In general, the group-specific options are transfered from the PROC CALIS statement to the MODEL statements (if present) and then to the fitted groups. In the transferring process, options are overwritten by the newer ones. If you want to apply some group-specific options to a particular group only, you should set those options in the GROUP statement corresponding to that group.