ERIC Number: ED333013
Record Type: RIE
Publication Date: 1991-Apr
Reference Count: 0
An Examination of the Effect of Multidimensionality on Parallel Forms Construction.
Ackerman, Terry A.
This paper examines the effect of using unidimensional item response theory (IRT) item parameter estimates of multidimensional items to create weakly parallel test forms using target information curves. To date, all computer-based algorithms that have been devised to create parallel test forms assume that the items are unidimensional. This paper focuses on one such algorithm, which was developed by R. M. Luecht and T. M. Hirsch. Unidimensional item parameter estimates were obtained by calibrating response data generated from two-dimensional item parameters. Using these unidimensional estimates, three sets of test items from a pool of 200 multidimensional items were selected for each of two different test lengths for three differently shaped target information functions. The item parameter estimates were obtained by calibrating five forms of the EAAP Mathematics usage test using the multidimensional IRT calibration program NOHARM. Response data were generated for 2,000 abilities. Observed score differences for each triad, based on the multidimensional item parameters, were then compared. Despite the multidimensionality of the selected items, the created forms appear to be quite parallel both unidimensionally and multidimensionally. Two tables and seven figures are included. (SLD)
Publication Type: Reports - Evaluative; Speeches/Meeting Papers
Education Level: N/A
Authoring Institution: N/A
Identifiers: Ability Estimates; Information Function (Tests); Item Parameters; Multidimensionality (Tests); Parallel Test Forms; Unidimensionality (Tests)
Note: Paper presented at the Annual Meeting of the National Council on Measurement in Education (Chicago, IL, April 1991).