CDM implements parameter estimation procedures for the
two core CDMs DINA and DINO (e.g.,de la Torre &
Douglas, 2004; Junker & Sijtsma, 2001; Templin &
Henson, 2006; the generalized DINA model for dichotomous attributes
(GDINA, de la Torre, 2011) and for polytomous attributes
(pGDINA, Chen & de la Torre, 2013);
the general diagnostic model (GDM, von Davier, 2008) and its extension
to the multidimensional latent class IRT model (Bartolucci, 2007),
and tools for analyzing data under the models.
These and related concepts are explained in detail in the
book about diagnostic measurement and CDMs by
Rupp, Templin and Henson (2010), and in such survey articles as
DiBello, Roussos and Stout (2007) and
upp and Templin (2008).
The package CDM is implemented based on the S3 system. It comes
with a namespace and consists of several external functions (functions the
package exports).
The package obtains a utility method for the simulation of artificial data based
on a CDM model (sim.din). It also contains seven internal functions
(functions not exported by the package): this are plot, print, and
summary methods for objects of the class din (plot.din,
print.din, summary.din), a print method for
objects of the class summary.din (print.summary.din),
and three functions for checking the input format and computing intermediate
information (CDM-internal). The features of the package CDM are
illustrated with an accompanying real dataset and Q-matrix
(fraction.subtraction.data and fraction.subtraction.qmatrix)
and artificial examples (Data-sim).##
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## ** CDM 2.5-16 (2013-11-29) **
## ** Cognitive Diagnostic Models **
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