The POLYSERIAL option has been added to the PROC CORR statement. The POLYSERIAL option requests a table of polyserial correlation coefficients. Polyserial correlation measures the correlation between two continuous variables that have a bivariate normal distribution, where only one variable is observed directly. Information about the unobserved variable is obtained through an observed ordinal variable that is derived from the unobserved variable by classifying its values into a finite set of discrete, ordered values.

In the Second Maintenance Release of SAS 9.3, the POLYCHORIC option has been added to the PROC CORR statement. The POLYCHORIC option requests a table of polychoric correlation coefficients. Polychoric correlation measures the correlation between two unobserved, continuous variables that have a bivariate normal distribution. Information about each unobserved variable is obtained through an observed ordinal variable that is derived from the unobserved variable by classifying its values into a finite set of discrete, ordered values (Olsson, 1979; Drasgow, 1986).