| Type: | Package |
| Title: | Item Response Theory Reliability |
| Version: | 0.1-1 |
| Date: | 2018-02-22 |
| Author: | Bjorn Andersson |
| Maintainer: | Bjorn Andersson <bjoern.h.andersson@gmail.com> |
| Description: | Estimation of reliability coefficients for ability estimates and sum scores from item response theory models as defined in Cheng, Y., Yuan, K.-H. and Liu, C. (2012) <doi:10.1177/0013164411407315> and Kim, S. and Feldt, L. S. (2010) <doi:10.1007/s12564-009-9062-8>. The package supports the 3-PL and generalized partial credit models and includes estimates of the standard errors of the reliability coefficient estimators, derived in Andersson, B. and Xin, T. (2018) <doi:10.1177/0013164417713570>. |
| License: | GPL-2 | GPL-3 |
| LazyLoad: | yes |
| Depends: | R(≥ 2.11.0), methods, stats, graphics |
| Imports: | ltm, mirt, fastGHQuad |
| NeedsCompilation: | no |
| Packaged: | 2018-02-22 12:47:35 UTC; bjorand |
| Repository: | CRAN |
| Date/Publication: | 2018-02-22 18:19:26 UTC |
Marginal and Test Reliability Coefficients with Item Response Theory
Description
A function to estimate marginal and test reliability from estimated item response theory models.
Usage
irtreliability(input, model, cats, relcoef = "trc", nquad = 49, SE = TRUE)
Arguments
input |
An object of class SingleGroupClass from package mirt. |
model |
A character vector indicating the item response theory model used, options are "GPCM" and "3-PL". |
cats |
A numeric vector indicating the number of possible categories for each item. |
relcoef |
A character vector indicting which reliability coefficients to calculate, options are "mrc" for the marginal reliability coefficient and "trc" for the test reliability coefficient. |
nquad |
The number of Gauss-Hermite quadrature points to be used. |
SE |
A logical vector denoting whether the standard errors for the reliability coefficient estimates should be calculated. |
Value
An S4 object of class 'relout' which includes the following slots
est |
The estimated coefficient. |
cov |
The estimated variance. |
pder |
The partial derivatives of the coefficient with respect to the item parameters. |
type |
The type of coefficient. |
Author(s)
References
Andersson, B. and Xin, T. (2018). Large Sample Confidence Intervals for Item Response Theory Reliability Coefficients. Educational and Psychological Measurement, 78, 32-45.
Cheng, Y., Yuan, K.-H. and Liu, C. (2012). Comparison of reliability measures under factor analysis and item response theory. Educational and Psychological Measurement, 72, 52-67.
Green, B. F., Bock, R. D., Humphreys, L. G., Linn, R. L. and Reckase, M. D. (1984). Technical guidelines for assessing computerized adaptive tests. Journal of Educational Measurement, 21, 347-360.
Kim, S. (2012). A note on the reliability coefficients for item response model-based ability estimates. Psychometrika, 77, 153-162.
Kim, S. and Feldt, L. S. (2010). The estimation of the IRT reliability coefficient and its lower and upper bounds, with comparisons to CTT reliability statistics. Asia Pacific Education Review, 11, 179-188.
Examples
#Generate 2-PL data
set.seed(14)
akX <- runif(15, 0.5, 2)
bkX <- rnorm(15)
data2pl <- matrix(0, nrow = 1000, ncol = 15)
for(i in 1:1000){
ability <- rnorm(1)
data2pl[i,1:15] <- (1 / (1 + exp(-akX *(ability - bkX)))) > runif(15)
}
#Estimate the 2-PL IRT model with package mirt
library(mirt)
sim2pl <- mirt(data.frame(data2pl), 1, "gpcm", SE = TRUE)
mrc2pl <- irtreliability(sim2pl, "GPCM", rep(2, 15), relcoef = "mrc")
trc2pl <- irtreliability(sim2pl, "GPCM", rep(2, 15))
Class "relout"
Description
Estimates of reliability coefficients and coefficients related to the reliability.
Objects from the Class
Objects can be created by calls of the form new("keout", ...).
Slots
- est
The estimated coefficient.
- cov
The estimated variance.
- pder
The partial derivatives of the coefficient with respect to the item parameters.
- type
The type of coefficient.
Author(s)
Examples
showClass("relout")