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ERIC Number: EJ1168728
Record Type: Journal
Publication Date: 2017-Dec
Pages: 30
Abstractor: As Provided
ISSN: EISSN-2330-8516
Unidimensional Vertical Scaling in Multidimensional Space. Research Report. ETS RR-17-29
Carlson, James E.
ETS Research Report Series, Dec 2017
In this paper, I consider a set of test items that are located in a multidimensional space, S[subscript M], but are located along a curved line in S[subscript M] and can be scaled unidimensionally. Furthermore, I am demonstrating a case in which the test items are administered across 6 levels, such as occurs in K-12 assessment across 6 grade levels, and for which a unidimensional vertical scale can be developed. I am limiting my coverage to dichotomously scored items because the models are much simpler than those for polytomously scored items. However, the concepts discussed can be extended to the latter type of item. I also limit my demonstrations to a 2-dimensional space, S[subscript 2], so I can geometrically represent my points in a 2-dimensional representation in this article. These concepts can also be extended to a higher-dimensional case.
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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