Ase2pl: Calculates the asymptotic covariance matrix of item parameter...

In DFIT: Differential Functioning of Items and Tests

Description

Calculates the asymptotic covariance matrix of item parameter estimates under the 2pl model

Usage

Ase2pl(
  itemParameters,
  distribution = "norm",
  distributionParameters = list(mean = 0, sd = 1),
  logistic = TRUE,
  sampleSize = 1,
  subdivisions = 5000
)

Arguments

itemParameters	A matrix or vector containing the item difficulties.
distribution	A string character indicating the generic name for the assumed distribution.
distributionParameters	A list of extra parameters for the distribution function.
logistic	A logical indicating whether the logistic or the normal metric should be used.
sampleSize	A value indicating the sample size.
subdivisions	A numeric value stating the maximum number of subdivisions for adaptive quadrature.

Value

ase A list containing the asymptotic matrices for each item

Author(s)

Victor H. Cervantes <vhcervantesb at unal.edu.co>

References

Li, Y. & Lissitz, R. (2004). Applications of the analytically derived standard errors of Item Response Theory item parameter estimates. Journal of educational measurement, 41(2), 85–117. doi:10.1111/j.1745-3984.2004.tb01109.x

DFIT documentation built on Aug. 17, 2021, 9:07 a.m.