Titlebook: Essays on Item Response Theory; Anne Boomsma,Marijtje A. J. Duijn,Tom A. B. Snijde Book 2001 Springer Science+Business Media New York 2001

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Using Parameter Expansion to Improve the Performance of the EM Algorithm for Multidimensional IRT Poand demographic variables. The IRT models are often multidimensional with prespecified traits, and maximum likelihood estimates (MLEs) are found using an EM algorithm, which is typically very slow to converge. We show that the slow convergence is due primarily to missing information about the correl

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Cross-Validating Item Parameter Estimation in Adaptive Testingstance of this problem, adaptive testing is likely to capitalize on estimation error. An empirical example of the phenomenon is discussed, and a strategy for cross-validating results from adaptive testing is proposed. Results from a simulation study on the strategy are presented.

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Reversibility Revisited and Other Comparisons of Three Types of Polytomous IRT Modelsartial credit models. In his research, and later in research by others, the three types of models were compared on various criteria. One of the criteria introduced in IRT modeling is the property of reversibility. In this chapter, the results of a number of comparison studies are summarized. Next, t

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艺术

The Life of Georg Rasch as a Mathematician and as a Statisticianforced by the employment situation in Denmark, had to turn to statistics after having graduated and defended his doctoral dissertation in pure mathematics. Finally, it is discussed at some length how Rasch, especially after 1960, formulated his requirements of proper measurement into the formalized concept of specific objectivity.

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Gain Scores Revisited Under an IRT Perspectives, and uniformly most powerful unbiased tests of the hypothesis of no change are presented. All methods are grounded on the exact conditional distribution of the gain score, given the total score for both time points, so that no asymptotic approximations are required. Typical applications of the methods are mentioned.

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Statistical Tests for Differential Test Functioning in Rasch’s Model for Speed Testsparameters. In this chapter, the principle of Lagrange multiplier tests is used to evaluate differential test functioning and subgroup invariance of the test parameters. Two numerical illustrations are given.