Comparing Multiunidimensional and Unidimensional Item Response Theory Models

¹ Southern Illinois University Carbondale
² University of Missouri-Columbia

^* To whom correspondence should be addressed. E-mail: ysheng{at}siu.edu.

	Abstract

For tests consisting of multiple subtests, unidimensional item response theory (IRT) models apply when the subtests are known to measure a common underlying ability. However, in many instances, due to the lack of a satisfactory index for assessing the dimensionality assumption, the test structure is not clear. A more general IRT model, the multiunidimensional model, is more flexible and efficient in various test situations. This article compares these two classes of normal ogive two-parameter models and shows that the multiunidimensional model offers a better way to represent test situations not realized in unidimensional models.

First published on May 25, 2007, doi:10.1177/0013164406296977

Educational and Psychological Measurement 2007;67:899.

A more recent version of this article appeared on December 1, 2007


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				J. de la Torre and H. Song Simultaneous Estimation of Overall and Domain Abilities: A Higher-Order IRT Model Approach Applied Psychological Measurement, November 1, 2009; 33(8): 620 - 639. [Abstract] [PDF]