sim.irt
and then scored using factor scores from factor.scores
using statistics found using irt.fa
, simple weighted models for 1 and 2 PL and 2 PN. Results show almost perfect agreement with estimates from MIRT and ltm for the dichotomous case and with MIRT for the polytomous case. (Results from ltm are unstable for the polytomous case, sometimes agreeing with scoreIrt
and MIRT, sometimes being much worse.)
test.irt(nvar = 9, n.obs = 1000, mod = "logistic",type="tetra", low = -3, high = 3, seed = NULL)
scoreIrt
,irt.fa