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ERIC Number: ED410300
Record Type: Non-Journal
Publication Date: 1997-Mar
Pages: 24
Abstractor: N/A
Reference Count: N/A
The Relationship between Polytomous DFIT and Other Polytomous DIF Procedures.
Flowers, Claudia P.; And Others
An item response theory-based parametric procedure proposed by N. S. Raju, W. J. van der Linden, and P. F. Fleer (1995) known as differential functioning of items and tests (DFIT) can be used with unidimensional and multidimensional data with dichotomous or polytomous scoring. This study describes the polytomous DFIT framework and evaluates and compares its performance to that of the extension of the SIBTEST procedure developed by R. Shealy and W. Stout (1993) and extended Lord's chi-square. Using simulated data, the effects of sample size (500 and 1,000 examinees), focal group distribution (N(0,1) and N(-1,1)) number of differential item functioning (DIF) items (0%, 10%, and 20%), magnitude of DIF, and the value of a-parameter were evaluated. Overall, the DFIT framework performed well. Type I error rates were affected by the number of DIF items, magnitude of DIF, and the value of the a-parameters. The DIF detection rates were affected by all the factors in the study. Future directions for research are discussed. (Contains 5 tables and 16 references.) (Author/SLD)
Publication Type: Reports - Evaluative; Speeches/Meeting Papers
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A