Table 1. Design of the intercorrelation matrix of the correlation coefficients for direct range restriction (DRR) and indirect range restriction (IRR).

DRR			IRR
	X	Y		X	Y	Z
X	1	rb/rpb	X	1	rb/rpb	r
Y	rb/rpb	1	Y	rb/rpb	1	rb/rpb
			Z	r	rb/rpb	1

X is the predictor variable; Y is the dichotomous criterion variable; Z is the selection variable in the case of IRR; r_b is the biserial correlation coefficient; r_pb is the point-biserial correlation coefficient; r is the Pearson correlation coefficient.