| cala {lazy.irtx} | R Documentation |
Calibration of Independently Estimated Sets of Item Parameters by Minimizing the LS Criterion Defined in terms of Parameter Values
cala(indata, baseform = 0, nsubj = 0, maxiter = 100, eps = 1e-05, init = 1, print = 1, debug = 0)
indata |
data frame containing at least following: |
baseform |
form number or 0 |
nsubj |
# of subjects in each form.
|
maxiter |
max of iteration for PCA |
eps |
eos for PCA |
init |
not used |
print |
> 0 to print results |
debug |
= 1 to print intermediate result |
This program finds u,v and b such taht
bhata[j,g] = u[g] + b[j] v[g] + error
j=1,2,..., # of items and g=1,2,..., # of forms,
using PCA with missing data, where bhat is the collection of estimated
b-parameters.
a[g] will be estimated as the average of ahat[j,g]/r[g] ,
c[g] will be estimated as the average of chat[j,g] ,
where r[g]=1/v[g]
A list of:
param Data frame containing the equated item parameters
uv Transformations from common scale to each scale
qr Transformations from each scale to common scale
nfini Vector of # of forms including each item
niinf Vector of # of items included in each form
fini List of the Forms including each item.
iinf List of the Items included in each form.
iftable Matrix of item x form indicating the inclusion pattern.
toP Vector of stating locations in ParamHat
fromP Vector of ending locations in ParamHat
iterPCA # of iterations needed for convergence.
nbPCA 3 of b-parameters processed by PCA.
nisolo # of items that are included in only one form.
ParamHat Item Paramter matrix analyzed by PCA
rmse LS criterion minimized.
Sayaka Arai & Shin-ichi Mayekawa (2011)
A comparison of equating methods and linking designs for developing
an item pool under item response theory.
Behaviormetrika, Vol. 38 No. 1, pp. 1-16
Shin-ich Mayekawa (1991) Chapter 4. Parameter Estimation. In Shiba Ed. Item Response Theory. pp87-129. (in Japanese)
# Binary Items res=cala( indata=paramCal1, baseform=1, print=2 ) # Mixture of Item Types res=cala( indata=paramCal2, baseform=1, print=2 )