Hostname: page-component-5f745c7db-q8b2h Total loading time: 0 Render date: 2025-01-06T07:30:44.227Z Has data issue: true hasContentIssue false

Testing Unidimensionality in Polytomous Rasch Models

Published online by Cambridge University Press:  01 January 2025

Karl Bang Christensen*
Affiliation:
National Institute of Occupational Health, Denmark Department of Biostatistics, University of Copenhagen
Jakob Bue Bjorner
Affiliation:
National Institute of Occupational Health, Denmark
Svend Kreiner
Affiliation:
Department of Biostatistics, University of Copenhagen
Jørgen Holm Petersen
Affiliation:
Department of Biostatistics, University of Copenhagen
*
Requests for reprints should be sent to Karl Bang Christensen, National Institute of Occupational Health, Lersø Parkallé 105, 2100 KBH Ø, DENMARK. E-Mail: kbc@ami.dk

Abstract

A fundamental assumption of most IRT models is that items measure the same unidimensional latent construct. For the polytomous Rasch model two ways of testing this assumption against specific multidimensional alternatives are discussed. One, a marginal approach assuming a multidimensional parametric latent variable distribution, and, two, a conditional approach with no distributional assumptions about the latent variable. The second approach generalizes the Martin-Löf test for the dichotomous Rasch model in two ways: to polytomous items and to a test against an alternative that may have more than two dimensions. A study on occupational health is used to motivate and illustrate the methods.

Type
Articles
Copyright
Copyright © 2002 The Psychometric Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

The authors would like to thank Niels Keiding, Klaus Larsen and the anonymous reviewers for valuable comments to a previous version of this paper. This research was supported by a grant from the Danish Research Academy and by a general research grant from Quality Metric, Inc.

References

Adams, R.J., Wilson, M., & Wang, W.C. (1997). The multidimensional random coefficients multinomial logit model. Applied Psychological Measurement, 21, 123.CrossRefGoogle Scholar
Agresti, A. (1993). Computing conditional maximum likelihood estimates for generalized Rasch models using simple loglinear models with diagonals parameters. Scandinavian Journal of Statistics, 20, 6371.Google Scholar
Andersen, E.B. (1973). A goodness of fit test for the Rasch model. Psychometrika, 38, 123140.CrossRefGoogle Scholar
Andersen, E.B. (1980). Discrete statistical models with social science applications. Amsterdam: North-Holland.Google Scholar
Andersen, E.B. (1995). Polytomous Rasch Models and their Estimation. In Fischer, G.H., & Molenaar, I.W. (Eds.), Rasch models—Foundations, recent developments, and applications (pp. 271291). Berlin: Springer-Verlag.Google Scholar
Andrich, D. (1978). A rating formulation for ordered response categories. Psychometrika, 43, 561573.CrossRefGoogle Scholar
Carstensen, C.H., & Rost, J. (2001). MULTIRA (Version 1.63) [Computer software and manual]. Retrieved from http://www.multira.de (In German—version 1.62 of the software is available in English)Google Scholar
Cressie, N., & Holland, P.W. (1983). Characterizing the manifest probabilities of trait models. Psychometrika, 48, 129141.CrossRefGoogle Scholar
de Leeuw, J., & Verhelst, N.D. (1986). Maximum likelihood estimation in generalized Rasch models. Journal of Educational Statistics, 11, 183196.CrossRefGoogle Scholar
Efron, B., & Tibshirani, R. (1993). An introduction to the bootstrap. London: Chapman & Hall.CrossRefGoogle Scholar
Glas, C.A.W., & Verhelst, N.D. (1995). Tests of fit for polytomous Rasch models. In Fischer, G.H., & Molenaar, I.W. (Eds.), Rasch models—Foundations, recent developments, and applications (pp. 325352). Berlin: Springer-Verlag.Google Scholar
Kelderman, H., & Rijkes, C.P.M. (1994). Loglinear multidimensional IRT models for polytomously scored items. Psychometrika, 59, 149176.CrossRefGoogle Scholar
Martin-Löf, P. (1970). Statistiska modeller: Anteckninger från seminarier läsåret 1969–70 utarbetade av Rolf Sundberg Statistical models. Notes from the academic year 1969–70. Stockholm: Institutet för försäkringsmatematik och matematisk statistik vid Stockholms universitet.Google Scholar
Masters, G.N. (1982). A Rasch model for partial credit scoring. Psychometrika, 47, 149174.CrossRefGoogle Scholar
Neyman, J., & Scott, E.L. (1948). Consistent estimates based on partially consistent observations. Econometrika, 16, 132.CrossRefGoogle Scholar
Rost, J., & Carstensen, C.H. (2002). Multidimensional Rasch measurement via item component models and faceted designs. Applied Psychological Measurement, 26, 4256.CrossRefGoogle Scholar
Self, S.G., & Liang, K.-Y. (1987). Asymptotic properties of maximum likelihood estimators and likelihood ratio tests under nonstandard conditions. Journal of the American Statistical Association, 82, 605610.CrossRefGoogle Scholar
Tjur, T. (1982). A Connection between Rasch's item analysis model and a multiplicative Poisson model. Scandinavian Journal of Statistics, 9, 2330.Google Scholar
van den Wollenberg, A.L. (1982). Two new test statistics for the Rasch model. Psychometrika, 47, 123139.CrossRefGoogle Scholar
Verhelst, N.D., Glas, C.A.W., & Verstralen, H.H.F.M (1995). OPLM: Computer program and manual. Arnhem: CITO.Google Scholar
Wu, M., Adams, R.J., & Wilson, M.R. (1998). ACER Conquest: Generalised item response modelling software. Hawthorn: Australian Council for Educational Research.Google Scholar
Zwinderman, A.H., & van den Wollenberg, A.L. (1990). Robustness of marginal maximum likelihood estimation in the Rasch model. Applied Psychological Measurement, 14, 7381.CrossRefGoogle Scholar