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Approximating the Conditional Distribution of Person Fit Indexes for Checking the Rasch Model

Published online by Cambridge University Press:  01 January 2025

Edward J. Bedrick*
Affiliation:
Department of Mathematics and Statistics, University of New Mexico
*
Requests for reprints should be sent to Edward J. Bedrick, Dept. of Mathematics and Statistics, University of New Mexico, Albuquerque, NM 87131. E-mail: [email protected]

Abstract

We present a simple approximation to the conditional distribution of goodness-of-fit statistics for the Rasch model, assuming that the item difficulties are known. The approximation is easily programmed, and gives relatively accurate assessments of conditional p-values for tests of length 10 or more. A few generalizations are discussed.

Type
Original Paper
Copyright
Copyright © 1997 The Psychometric Society

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Footnotes

The author would like to thank the referees for suggestions that improved the presentation of the paper.

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