equateIRT (version 2.5.1)

sd.test: Test on Chain Equating Coefficients

Description

Performs a statistical test to verify if the chain equating coeffients that link the same two forms are equal.

Usage

sd.test(ecall)

Value

An object of class idtest with components

link

paths

AB

statistic

df

p.value

Arguments

ecall

list of objects of class eqc or ceqc returned by functions direc and chainec.

Author

Michela Battauz

References

Battauz, M. (2022). Testing for differences in chain equating. Statistica Neerlandica, 1-12.

See Also

chainec

Examples

# the following code uses item parameter estimates previously obtained
# for other examples see documentation in function chainec

# three-parameter logistic model
# direct equating coefficients using the "Haebara" method
data(est3pl)
test <- paste("test", 1:5, sep = "")
mod3pl <- modIRT(coef = est3pl$coef, var = est3pl$var, names = test, display = FALSE)
direclist3pl <- alldirec(mods = mod3pl, method = "Haebara")
# compute chain equating coefficients for path 1,2,3,4,5
pth3 <- paste("test", 1:5, sep = "")
chainec3 <- chainec(direclist = direclist3pl, pths = pth3)
# create a list of objects of class eqc or ceqc
ecall <- c(chainec3, direclist3pl["test1.test5"])
summary(chainec3)
summary(direclist3pl$test1.test5)
# test
sd.test(ecall)