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ERIC Number: EJ822891
Record Type: Journal
Publication Date: 2009-Jan
Pages: 23
Abstractor: As Provided
Reference Count: 20
ISSN: ISSN-0895-7347
Item Position and Item Difficulty Change in an IRT-Based Common Item Equating Design
Meyers, Jason L.; Miller, G. Edward; Way, Walter D.
Applied Measurement in Education, v22 n1 p38-60 Jan 2009
In operational testing programs using item response theory (IRT), item parameter invariance is threatened when an item appears in a different location on the live test than it did when it was field tested. This study utilizes data from a large state's assessments to model change in Rasch item difficulty (RID) as a function of item position change, test level, test content, and item format. As a follow-up to the real data analysis, a simulation study was performed to assess the effect of item position change on equating. Results from this study indicate that item position change significantly affects change in RID. In addition, although the test construction procedures used in the investigated state seem to somewhat mitigate the impact of item position change, equating results might be impacted in testing programs where other test construction practices or equating methods are utilized. (Contains 10 figures and 3 tables.)
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Publication Type: Journal Articles; Reports - Evaluative
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A