Pelton Timothy W, Bunderson C Victor
Department of Curriculum and Instruction, University of Victoria, PO Box 3010 STN CSC, Victoria, British Columbia, Canada V8W 3N4.
J Appl Meas. 2003;4(3):269-81.
This paper attempts to illuminate some of the practical limitations that the Rasch model (and by extension, Item Response Theory models) may have by focusing on the recovery of the density scale. Five simulation trials were conducted: the first four to recover the density scale with different deviations from the assumptions implicit in the use of the Rasch model and the fifth trial with an almost ideal data set. Results demonstrate that when error distributions are insufficient the results may be ordinal at best, and when error distributions are non-symmetrical, the positions of items may be biased with respect to the positions of persons. Results also confirm that errors of estimation, and test and sample information functions are sample dependent.
本文试图通过聚焦密度量表的恢复，阐明拉施模型（以及由此延伸的项目反应理论模型）可能存在的一些实际局限性。进行了五次模拟试验：前四次试验在与使用拉施模型时隐含的假设存在不同偏差的情况下恢复密度量表，第五次试验使用的是几乎理想的数据集。结果表明，当误差分布不充分时，结果充其量可能只是序数的，而当误差分布不对称时，项目的位置相对于人的位置可能会有偏差。结果还证实，估计误差以及测试和样本信息函数取决于样本。
