Psych Package - Extract factor scores from fa.poly function

Question

I used fa.poly function for factor analysis of categorical manifest variables. I am now trying to extract the factor scores from the results. However, the str function indicates that factor scores are not "stored" in the results.

This is in contrast to the factor analysis function for continuous variables - fa - where the scores are stored in the results and can be extracted using results$scores

results <- fa.poly(inputdata, 4, fm = "pa", rotate = "oblimin")

results$scores gives NULL

VERSUS

results2 <- fa(inputdata, 4, fm = "pa", rotate = "oblimin")

results2$scores gives desired results

Answer 1

Please update to 1.3.10.12 which was just added to Cran this weekend. I finally got around to allowing you to do this.

Bill

Answer 2

Use the fa function, but add cor="poly" to the code to make sure it uses the polychoric correlation for ordinal variables:

results2 <- fa(inputdata, 4, fm = "pa", rotate = "oblimin", cor = "poly")