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Abstract

This study investigated the effect of using multidimensional items in a computerized adaptive test (CAT) setting which assumes that all items are unidimensional. Previous research has suggested that the composite of multidimensional abilities being estimated by a unidimensional IRT model is not constant throughout the entire unidimensional ability scale (Reckase, Carlson, Ackerman, & Spray, 1986). Results of this study suggest that unidimensional calibration of multidimensional data tends to "filter out" the multidimensionality. Items that measured a θ₁,θ₂ composite similar to the composite of the calibrated unidimensional θ scale had larger estimated unidimensional discrimination values. These items thus had a greater probability of being administered in a CAT where only the most informative items are selected. Results also suggest that if a CAT item pool contains items from several content areas measuring dissimilar θ₁,θ₂ composites, different unidimensional abilities may receive disparate proportions of items from the various content areas.

Keywords

Index terms: adaptive testing item response theory multidimensionality parallel tests test construction.

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References

American College Testing Program. (1986). The ACT Assessment test preparation reference manual for teachers and counselors . Iowa City IA: Author.

Carlson, J.E. (1987). Multidimensional item response theory estimation: A computer program. Unpublished manuscript.

Reckase, M.D. (1985). The difficulty of test items that measure more than one ability. Applied Psychological Measurement, 9, 401-412.

Reckase, M.D. (April, 1986). The discriminating power of items that measure more than one dimension. Paper presented at the annual meeting of the American Educational Research Association, San Francisco CA, U.S.A.

Reckase, M.D. , Carlson, J.E. , Ackerman, T.A. , & Spray, J.A. (June, 1986). The interpretation of unidimensional IRT parameters estimated from multidimensional data. A paper presented at the annual meeting of the Psychometric Society, Toronto, Ontario, Canada.

Samejima, F. (1977). A use of the information function in tailored testing. Applied Psychological Measurement, 1, 233-247.

Traub, R.E. (1983). A priori considerations in choosing an item response model. In R. K. Hambleton (Ed.), Applications of item response theory (pp. 57-70). Vancouver, British Columbia: Educational Research Institute of British Columbia.

Wang, M.M. (1986). Fitting a unidimensional model to multidimensional item response data. Paper presented at the annual meeting of the Office of Naval Research Contractor's Meeting, Knoxville TN, U.S.A.

Weiss, D.J. , & Suhadolnik, D. (1982). Robustness of adaptive testing to multidimensionality. In D. J. Weiss (Ed.), Proceedings of the 1982 item response theory and computerized adaptive testing conference Minneapolis MN: University of Minnesota, Department of Psychology, Computerized Adaptive Testing Laboratory.

10.

Wingersky, M.S. , Barton, M.A. , & Lord, F.M. (1982). LOGIST user's guide. Princeton NJ.: Educational Testing Service.

The Use of Unidimensional Parameter Estimates of Multidimensional Items in Adaptive Testing

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