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ERIC Number: EJ1110988
Record Type: Journal
Publication Date: 2009-Dec
Pages: 29
Abstractor: As Provided
Reference Count: 23
ISSN: EISSN-2330-8516
Evaluating Subpopulation Invariance of Linking Functions to Determine the Anchor Composition for a Mixed-Format Test. Research Report. ETS RR-09-36
Kim, Sooyeon; Walker, Michael E.
ETS Research Report Series, Dec 2009
We examined the appropriateness of the anchor composition in a mixed-format test, which includes both multiple-choice (MC) and constructed-response (CR) items, using subpopulation invariance indices. We derived linking functions in the nonequivalent groups with anchor test (NEAT) design using two types of anchor sets: (a) MC only and (b) a mix of MC and CR. In each anchor condition, we derived the linking functions separately for males and females and then compared those subpopulation functions to the total group function. In the MC-only condition, the difference between the subpopulation functions and the total group function was not trivial in a score region that included cut scores, leading to inconsistent pass/fail decisions for low-performing examinees in particular. Overall, the mixed anchor was a better choice than the MC-only anchor to achieve subpopulation invariance between males and females. The research reinforces subpopulation invariance indices as a means of determining the adequacy of the anchor.
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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