| simMG {irtQ} | R Documentation |
Simulated multiple-group data
Description
This data set has a list consisting of item metadata, item response data, and group names of three simulated groups.
Usage
simMG
Format
This data set includes a list of three internal objects: (1) a list of item metadata (item.prm) for three groups, (2) a list of item response data (res.dat) for the three groups, and (3) a vector of group names (group.name) for the three groups.
The first internal object (item.prm) contains a list of item metadata of three test forms for the three groups. In terms of test forms, the test forms for the first and second groups have fifty items consisting of forty seven 3PLM items and three GRM items. The test form for the third group has thirty eight items consisting of thirty seven 3PLM items and one GRM item. Among the three forms, the first and second test forms share twelve common items (C1I1 through C1I12) and the second and third test forms share ten common items (C2I1 through c2I10). There is no common item between the first and third forms. The item parameters in the item metadata were used to simulate the item response data sets for the three groups (see the second object of the list).
Regrading the second internal object, all three response data sets were simulated with 2,000 latent abilities randomly sampled
from N(0, 1) (Group 1), N(0.5, 0.8^{2}) (Group 2), and N(-0.3, 1.3^{2}) (Group 3), respectively, using the
true item parameters provided in the item metadata.
The third internal object is a vector of three group names which are "Group1", "Group2", and "Group3".
Author(s)
Hwanggyu Lim hglim83@gmail.com