link-class {plink} | R Documentation |
Class "link"
Description
The formal S4 class for link. This class compiles the linking constants,
item parameter descriptive statistics, and iteration/objective/convergence information
for the moment methods and characteristic curve methods of a separate calibration linking
procedure.
Objects from the Class
Objects can be created by calls of the form new("link", ...)
, but this is
not encouraged. Use the function link[=plink-methods{plink}
instead.
Slots
constants
:- list of linking methods where the list elements include
the linking constants. For unidimensional models, each element is a vector of
length two containing a slope and intercept to adjust the SD and mean respectively.
For multidimensional models, each element is a list with a matrix (or set of
matrices) to resolve rotational indeterminacy and scale, and a vector of
translation constants to adjust the mean of each dimension.
descriptives
:- data.frame or list containing the item parameter
descriptive statistics
iterations
:- vector of the number of optimization iterations for
the Haebara and Stocking-Lord methods
objective
:- vector of criterion values for HBcrit and SLcrit at the point
of convergence for the Haebara and Stocking-Lord methods
convergence
:- character vector identifying the type of convergence
reached under the Haebara or Stocking-Lord optimizations.
(see http://netlib.bell-labs.com/cm/cs/cstr/153.pdf for more
information on the output values)
base.grp
:- numeric value indicating the base group for the calibration
n
:- vector identifying the total number of common items, the number of
dichotomous common items, and the number of polytomous common items
grp.names
:- character vector of group names
mod.lab
:- character vector identifying the dichotomous and/or polytomous
models used to model the item responses
dilation
:- character value identifying the dilation approach used when
estimating multidimensional linking constants
include.mcm.nrm
:- logical vector indicating whether multiple-choice
model or nominal response model items were included in the computation of
the linking constants
Author(s)
Jonathan P. Weeks weeksjp@gmail.com
See Also
plink
[Package
plink version 1.0.0
Index]