Open AccessIDENTIFIABILITY OF PARAMETERS IN ITEM RESPONSE MODELS WITH UNCONSTRAINED ABILITY DISTRIBUTIONS
Author(s) -
Haberman Shelby J.
Publication year - 2005
Publication title -
ets research report series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.235
H-Index - 5
ISSN - 2330-8516
DOI - 10.1002/j.2333-8504.2005.tb02001.x
Subject(s) - identifiability , rasch model , item response theory , parametric statistics , differential item functioning , econometrics , mathematics , parametric model , logistic regression , distribution (mathematics) , statistics , psychometrics , mathematical analysis
ABSTRACT If a parametric model for the ability distribution is not assumed, then the customary two‐parameter and three‐parameter logistic models for item response analysis present identifiability problems not encountered with the Rasch model. These problems impose substantial restrictions on possible models for ability distributions.