NORMALIZATION Subcommand (MULTIPLE CORRESPONDENCE command)

The NORMALIZATION subcommand specifies one of five options for normalizing the object scores and the variables.

• Only one normalization method can be used in a given analysis.

VPRINCIPAL. Optimize the association between variables. With VPRINCIPAL, the categories are in the centroid of the objects in the particular categories. VPRINCIPAL is the default if the NORMALIZATION subcommand is not specified. This is useful when you are primarily interested in the association between the variables.

OPRINCIPAL. Optimize distances between objects. This is useful when you are primarily interested in differences or similarities between the objects.

SYMMETRICAL. Use this normalization option if you are primarily interested in the relation between objects and variables.

INDEPENDENT. Use this normalization option if you want to examine distances between objects and associations between variables separately.

The fifth method allows the user to specify any real value in the closed interval [–1, 1]. A value of 1 is equal to the OPRINCIPAL method, a value of 0 is equal to the SYMMETRICAL method, and a value of –1 is equal to the VPRINCIPAL method. By specifying a value greater than –1 and less than 1, the user can spread the eigenvalue over both objects and variables. This method is useful for making a tailor-made biplot. If the user specifies a value outside of this interval, the procedure issues a syntax error message and terminates.