This function calculates the variance of DIF effects, the so called DIF variance (Longford, Holland & Thayer, 1993).
dif.variance(dif, se.dif, items=paste("item", 1:length(dif), sep="") )
A list with following entries
Weighted DIF standard deviation
DIF standard deviation
Mean of standard errors of DIF effects
Empirical Bayes estimates of DIF effects
Vector of uniform DIF effects
Standard error of uniform DIF effects
Optional vector of item names
Longford, N. T., Holland, P. W., & Thayer, D. T. (1993). Stability of the MH D-DIF statistics across populations. In P. W. Holland & H. Wainer (Eds.). Differential Item Functioning (pp. 171-196). Hillsdale, NJ: Erlbaum.
See dif.logistic.regression
for examples.