ERIC Number: ED347170
Record Type: RIE
Publication Date: 1992-Apr
Reference Count: N/A
Assessing the Impact of Multidimensionality on the Classification Decisions of an IRT-Based Licensure Examination.
Sykes, Robert C.; And Others
A part-form methodology was used to study the effect of varying degrees of multidimensionality on the consistency of pass/fail classification decisions obtained from simulated unidimensional item response theory (IRT) based licensure examinations. A control on the degree of form multidimensionality permitted an assessment throughout the range of multidimensionality of any potential effect on Rasch item parameters and pass/fail classifications obtained from scores derived from them. Four full-length (300-item) forms of a licensure examination produced by CTB Macmillan/McGraw Hill were used to generate part-forms for four administrations in the summer of 1988, winter of 1989, summer of 1989, and winter of 1990, respectively. There were 2,000 examinees for each form. All four full-length forms had been demonstrated to be multidimensional, but could be made unidimensional by deleting no more than half the items with the largest absolute loadings on the second factor. Overall, failure concordance percentages did not differ between those pairs of part-forms that differed maximally in the degree of predicted multidimensionality and those pairs of part-forms where members were both predicted to be multidimensional. Results suggest that increased multidimensionality had no substantial effect on failure decision agreement. However, the failure concordance percentages for pairs of part-forms that were both most likely unidimensional were slightly higher than those for other pairs of part-forms. Four tables, 1 figure of study data and 12 references are included. (SLD)
Publication Type: Reports - Evaluative; Speeches/Meeting Papers
Education Level: N/A
Authoring Institution: N/A
Identifiers: Multidimensionality (Tests); Part Form Method; Rasch Model
Note: Paper presented at the Annual Meeting of the National Council on Measurement in Education (San Francisco, CA, April 21-23, 1992).