poly.mod-class: Class "poly.mod"
Description
The formal S4 class for poly.mod. This class characterizes the models and
associated items for a set of item parameters.Objects from the Class
Objects can be created by calls of the form new("poly.mod", ...)
, but this is
not encouraged. Use the function as.poly.mod
instead.Slots
model
:- character vector identifying all the models associated with the
corresponding set of item parameters. The only acceptable models are
drm
, gpcm
, grm
, mcm
, and nrm
. See below for more
details. items
:- list with the same length as
model
, where each element
identifies the items(rows) in the corresponding set of item parameters associated
with the model(s) identified in model
.
Details
The IRT models associated with the codes:
drm
:- dichotomous response models (includes 1PL, 2PL, and 3PL)
gpcm
:- generalized partial credit model (includes the
partial credit model)
grm
:- graded response model
mcm
:- multiple-choice model
nrm
:- nominal response model