Abstract
A commonly used method to evaluate the accuracy of a measurement is to provide a confidence interval that contains the parameter of interest with a given high probability. Smallest exact confidence intervals for the ability parameter of the Rasch model are derived and compared to the traditional, asymptotically valid intervals based on the Fisher information. Tables of the exact confidence intervals, termed Clopper-Pearson intervals, can be routinely drawn up by applying a computer program designed by and obtainable from the author. These tables are particularly useful for tests of only moderate lengths where the asymptotic method does not provide valid confidence intervals.
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Klauer, K.C. Exact and best confidence intervals for the ability parameter of the Rasch model. Psychometrika 56, 535–547 (1991). https://doi.org/10.1007/BF02294489
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DOI: https://doi.org/10.1007/BF02294489