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ERIC Number: EJ819614
Record Type: Journal
Publication Date: 2008
Pages: 16
Abstractor: As Provided
Reference Count: 36
ISSN: ISSN-0022-0655
Performance of the Generalized S-X[Superscript 2] Item Fit Index for Polytomous IRT Models
Kang, Taehoon; Chen, Troy T.
Journal of Educational Measurement, v45 n4 p391-406 Win 2008
Orlando and Thissen's S-X[superscript 2] item fit index has performed better than traditional item fit statistics such as Yen' s Q[subscript 1] and McKinley and Mill' s G[superscript 2] for dichotomous item response theory (IRT) models. This study extends the utility of S-X[superscript 2] to polytomous IRT models, including the generalized partial credit model, partial credit model, and rating scale model. The performance of the generalized S-X[superscript 2] in assessing item model fit was studied in terms of empirical Type I error rates and power and compared to G[superscript 2]. The results suggest that the generalized S-X[superscript 2] is promising for polytomous items in educational and psychological testing programs. (Contains 2 figures, 3 tables, and 52 formulas.)
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A