data(karabatsos2004)
head(karabatsos2004)
######################################################
##### Testing Monotonicity (M) #####
##### (Karabatsos & Sheu, 2004, Table 3, p. 120) #####
IJ <- dim(karabatsos2004$k.M)
monotonicity <- nirt_to_Ab(IJ[1], IJ[2], axioms = "W1")
p <- sampling_binom(
k = c(karabatsos2004$k.M),
n = c(karabatsos2004$n.M),
A = monotonicity$A, b = monotonicity$b,
prior = c(.5, .5), M = 300
)
# posterior means (Table 4, p. 120)
post.mean <- matrix(apply(p, 2, mean), IJ[1],
dimnames = dimnames(karabatsos2004$k.M)
)
round(post.mean, 2)
# posterior predictive checks (Table 4, p. 121)
ppp <- ppp_binom(p, c(karabatsos2004$k.M), c(karabatsos2004$n.M),
by = 1:prod(IJ)
)
ppp <- matrix(ppp[, 3], IJ[1], dimnames = dimnames(karabatsos2004$k.M))
round(ppp, 2)
######################################################
##### Testing invariant item ordering (IIO) #####
##### (Karabatsos & Sheu, 2004, Table 6, p. 122) #####
IJ <- dim(karabatsos2004$k.IIO)
iio <- nirt_to_Ab(IJ[1], IJ[2], axioms = "W2")
p <- sampling_binom(
k = c(karabatsos2004$k.IIO),
n = c(karabatsos2004$n.IIO),
A = iio$A, b = iio$b,
prior = c(.5, .5), M = 300
)
# posterior predictive checks (Table 6, p. 122)
ppp <- ppp_binom(prob = p, k = c(karabatsos2004$k.IIO),
n = c(karabatsos2004$n.IIO), by = 1:prod(IJ))
matrix(ppp[,3], 7, dimnames = dimnames(karabatsos2004$k.IIO))
# for each item:
ppp <- ppp_binom(p, c(karabatsos2004$k.IIO), c(karabatsos2004$n.IIO),
by = rep(1:IJ[2], each = IJ[1]))
round(ppp[,3], 2)
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