discrim.index {CDM} | R Documentation |
Discrimination Indices at Item-Attribute, Item and Test Level
Description
Computes discrimination indices at the probability metric (de la Torre, 2008; Henson, DiBello & Stout, 2018).
Usage
discrim.index(object, ...)
## S3 method for class 'din'
discrim.index(object, ...)
## S3 method for class 'gdina'
discrim.index(object, ...)
## S3 method for class 'mcdina'
discrim.index(object, ...)
## S3 method for class 'discrim.index'
summary(object, file=NULL, digits=3, ...)
Arguments
object |
|
file |
Optional file name for a file in which the summary output should be sunk |
digits |
Number of digits for rounding |
... |
Further arguments to be passed |
Details
If item possesses
categories, the item-attribute
specific discrimination for attribute
according to Henson et al. (2018) is defined as
where and
differ only
in attribute
. The index
can be found as the
value
discrim_item_attribute
. The test-level discrimination index
is defined as
and can be found
in discrim_test
.
According to de la Torre (2008) and de la Torre, Rossi and van der Ark (2018), the item discrimination index (IDI) is defined as
and can be found as idi
in the values list.
Value
A list with following entries
discrim_item_attribute |
Discrimination indices |
idi |
Item discrimination index |
discrim_test |
Discrimination index at test level |
References
de la Torre, J. (2008). An empirically based method of Q-matrix validation
for the DINA model: Development and applications.
Journal of Educational Measurement, 45, 343-362.
http://dx.doi.org/10.1111/j.1745-3984.2008.00069.x
de la Torre, J., van der Ark, L. A., & Rossi, G. (2018). Analysis of clinical data from a cognitive diagnosis modeling framework. Measurement and Evaluation in Counseling and Development, 51(4), 281-296. https://doi.org/10.1080/07481756.2017.1327286
Henson, R., DiBello, L., & Stout, B. (2018). A generalized approach to defining item
discrimination for DCMs.
Measurement: Interdisciplinary Research and Perspectives, 16(1), 18-29.
http://dx.doi.org/10.1080/15366367.2018.1436855
See Also
See cdi.kli
for discrimination indices based on the
Kullback-Leibler information.
For a fitted model mod
in the GDINA package, discrimination indices can be
extracted by the method extract(mod,"discrim")
(GDINA::extract
).
Examples
## Not run:
#############################################################################
# EXAMPLE 1: DINA and GDINA model
#############################################################################
data(sim.dina, package="CDM")
data(sim.qmatrix, package="CDM")
#-- fit GDINA and DINA model
mod1 <- CDM::gdina( sim.dina, q.matrix=sim.qmatrix )
mod2 <- CDM::din( sim.dina, q.matrix=sim.qmatrix )
#-- compute discrimination indices
dimod1 <- CDM::discrim.index(mod1)
dimod2 <- CDM::discrim.index(mod2)
summary(dimod1)
summary(dimod2)
## End(Not run)