ANALYSIS Subcommand (OVERALS command)

ANALYSIS specifies the variables to be used in the analysis and the optimal scaling level at which each variable is to be analyzed.

  • The ANALYSIS subcommand is required and follows the VARIABLES subcommand.
  • The specification on ANALYSIS is a variable list and an optional keyword in parentheses, indicating the level of optimal scaling.
  • The variables on ANALYSIS must also be specified on the VARIABLES subcommand.
  • Only active variables are listed on the ANALYSIS subcommand. Active variables are those variables that are used in the computation of the solution. Passive variables, those variables that are listed on the VARIABLES subcommand but not on the ANALYSIS subcommand, are ignored in the OVERALS solution. Object score plots can still be labeled by passive variables.

The following keywords can be specified to indicate the optimal scaling level:

MNOM. Multiple nominal. The quantifications can be different for each dimension. When all variables are multiple nominal, and there is only one variable in each set, OVERALS gives the same results as HOMALS.

SNOM. Single nominal. OVERALS gives only one quantification for each category. Objects in the same category (cases with the same value on a variable) obtain the same quantification. When all variables are SNOM, ORDI, or NUME, and there is only one variable per set, OVERALS gives the same results as PRINCALS.

ORDI. Ordinal. This setting is the default for variables that are listed without optimal scaling levels. The order of the categories of the observed variable is preserved in the quantified variable.

NUME. Numerical. Interval or ratio scaling level. OVERALS assumes that the observed variable already has numerical values for its categories. When all variables are quantified at the numerical level, and there is only one variable per set, the OVERALS analysis is analogous to classical principal components analysis.

These keywords can apply to a variable list as well as to a single variable. Thus, the default ORDI is not applied to a variable without a keyword if a subsequent variable on the list has a keyword.