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ERIC Number: EJ1109925
Record Type: Journal
Publication Date: 2012-Sep
Pages: 15
Abstractor: As Provided
ISSN: EISSN-2330-8516
A Note on the Choice of an Anchor Test in Equating. Research Report. ETS RR-12-14
Sandip, Sinharay; Haberman, Shelby; Holland, Paul; Lewis, Charles
ETS Research Report Series, Sep 2012
Anchor tests play a key role in test score equating. We attempt to find, through theoretical derivations, an anchor test with optimal item characteristics. The correlation between the scores on a total test and on an anchor test is maximized with respect to the item parameters for data satisfying several item response theory models. Results suggest that under these models, the "minitest," the traditionally used anchor test, is not optimal with respect to anchor-test-to-total-test correlation; instead, an anchor test with items of medium difficulty, the "miditest," seems to be the optimum anchor test. This finding agrees with the empirical findings of Sinharay and colleagues that the miditest mostly has higher anchor-test-to-total-test correlation compared to the minitest and mostly performs as well as the minitest in equating.
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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