This Article Full Text (OnlineFirst PDF) All Versions of this Article: 0013164407313366v1 68/4/695    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Immekus, J. C. Articles by Imbrie, P. K. Search for Related Content Social Bookmarking                   What's this?

Dimensionality Assessment Using the Full-Information Item Bifactor Analysis for Graded Response Data: An Illustration With the State Metacognitive Inventory

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

	Abstract

Dimensionality assessment using the full-information item bifactor model for graded response data is provided. The model applies to data in which each item relates to a general factor and one group factor. Specifically, alternative model specification within item response theory (IRT) is shown to test a scale’s factor structure. For illustrative purposes, the bifactor model and competing IRT models were fit to the data of separate cohorts of incoming college students (Cohort 1, n = 1,490; Cohort 2, n = 1,533) to test the dimensionality of an adapted version of the State Metacognitive Inventory. Overall, the bifactor analysis did not strongly support distinct group factors after accounting for the general factor. Instead, results suggested conceptualizing the scale as unidimensional, indicating that scores should be based on the total scale, not subscales. Considerations related to the use of the bifactor IRT model are discussed.

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