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ERIC Number: EJ718412
Record Type: Journal
Publication Date: 2005-Jul
Pages: 21
Abstractor: Author
ISBN: N/A
ISSN: ISSN-0022-0655
EISSN: N/A
Available Date: N/A
Comparison of NOHARM and DETECT in Item Cluster Recovery: Counting Dimensions and Allocating Items
Finch, Holmes; Habing, Brian
Journal of Educational Measurement, v42 n2 p149-169 Jul 2005
This study examines the performance of a new method for assessing and characterizing dimensionality in test data using the NOHARM model, and comparing it with DETECT. Dimensionality assessment is carried out using two goodness-of-fit statistics that are compared to reference X[2] distributions. A Monte Carlo study is used with item parameters based on a statewide basic skills assessment and the SAT. Other factors that are varied include the correlation among the latent traits, the number of items, the number of subjects, skewness of the latent traits, and the presence or absence of guessing. The performance of the two procedures is judged by the accuracy in determining the number of underlying dimensions, and the degree to which items are correctly clustered together. Results indicate that the new, NOHARM-based method appears to perform comparably to DETECT in terms of simultaneously finding the correct number of dimensions and clustering items correctly. NOHARM is generally better able to determine the number of underlying dimensions, but less able to group items together, than DETECT. When errors in item cluster assignment are made, DETECT is more likely to incorrectly separate items while NOHARM more often incorrectly groups them together.
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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
Identifiers - Assessments and Surveys: SAT (College Admission Test)
Grant or Contract Numbers: N/A
Author Affiliations: N/A