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ERIC Number: EJ1111171
Record Type: Journal
Publication Date: 2010-Feb
Pages: 29
Abstractor: As Provided
ISSN: EISSN-2330-8516
Differential Item Functioning: Its Consequences. Research Report. ETS RR-10-01
Lee, Yi-Hsuan; Zhang, Jinming
ETS Research Report Series, Feb 2010
This report examines the consequences of differential item functioning (DIF) using simulated data. Its impact on total score, item response theory (IRT) ability estimate, and test reliability was evaluated in various testing scenarios created by manipulating the following four factors: test length, percentage of DIF items per form, sample sizes of different examinee groups, and types of responses. The results indicate that the greatest score difference was observed between the examinee groups on forms with DIF items, and the magnitude was less than 2 points on the 0-60 total score scale and 0.15 on the IRT ability scale. The influence on reliability was rather limited.
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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
Grant or Contract Numbers: N/A