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Scale Alignment in Between‐Item Multidimensional Rasch Models
Author(s) -
Feuerstahler Leah,
Wilson Mark
Publication year - 2019
Publication title -
journal of educational measurement
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.917
H-Index - 47
eISSN - 1745-3984
pISSN - 0022-0655
DOI - 10.1111/jedm.12209
Subject(s) - rasch model , polytomous rasch model , item response theory , scale (ratio) , context (archaeology) , logistic regression , statistics , computer science , econometrics , artificial intelligence , psychometrics , mathematics , geography , cartography , archaeology
Scores estimated from multidimensional item response theory (IRT) models are not necessarily comparable across dimensions. In this article, the concept of aligned dimensions is formalized in the context of Rasch models, and two methods are described—delta dimensional alignment (DDA) and logistic regression alignment (LRA)—to transform estimated item parameters so that dimensions are aligned. Both the DDA and LRA methods are applied to real and simulated data, and it is demonstrated that both methods are broadly effective for achieving aligned scales. The routine use of scale alignment methods is recommended prior to comparing scores across dimensions.