Polyserial-coefficient: Polyserial correlation coefficient
In SICSresearch/IRTpp_old: Estimating IRT parameters using the IRT Methodology

Description Usage Arguments Details Value References

Polyserial correlation coefficient is a correlation coefficient used when one variable is continuous and the other variable is dichotomous. License :GPL Adapted from ltm_1.0 package

1	polyserial.cor(x,y)

`x`	a numeric vector representing the continuous variable.
`y`	a numeric vector representing the dichotomous variable.

The coefficient is calculated from rho = r_xy * sqrt(n - 1)/n * s_y/sumphi(tau) where r_xy is the coefficient of correlation of Pearson coefficient, S_y is the standard deviation of Y, and phi(tau) are the ordinates of the normal curve at the normal equivalent of the cut point boundaries between the item responses.

the value of the polyserial correlation.

U.Olsson, F.Drasgow, and N.Dorans (1982). The polyserial correlation coefficient. Psychometrika, 47:337-347.

SICSresearch/IRTpp_old documentation built on May 9, 2019, 11:12 a.m.