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ERIC Number: EJ808666
Record Type: Journal
Publication Date: 2008
Pages: 17
Abstractor: As Provided
ISSN: ISSN-0013-1644
Methods for Assessing Item, Step, and Threshold Invariance in Polytomous Items Following the Partial Credit Model
Penfield, Randall D.; Myers, Nicholas D.; Wolfe, Edward W.
Educational and Psychological Measurement, v68 n5 p717-733 2008
Measurement invariance in the partial credit model (PCM) can be conceptualized in several different but compatible ways. In this article the authors distinguish between three forms of measurement invariance in the PCM: step invariance, item invariance, and threshold invariance. Approaches for modeling these three forms of invariance are proposed, and the mathematical relationship between the three forms is established. Parametric and contingency table approaches for assessing the three forms of invariance are presented, and the application of the parametric and contingency table approaches to a real data set is described. The invariance effect estimates observed for the parametric and contingency table approaches are consistent with the theoretical equivalence of the two approaches. (Contains 3 tables.)
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Publication Type: Journal Articles; Reports - Evaluative
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A