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Accuracy Of Rasch Model Item Parameter Estimation, Luc Le, Ray Adams
Accuracy Of Rasch Model Item Parameter Estimation, Luc Le, Ray Adams
Dr Luc Tu Le
This study used Monte Carlo simulations to evaluate the item parameter recovery from ACER ConQuest 3 software (Adams, Wu, & Wilson, 2012) for the dichotomous Rasch model. The authors’ primary focus was the comparison of its estimation methods, joint maximum likelihood (JML), marginal maximum likelihood (MML) with a normal distribution assumption and MML with a discrete distributions assumption when the populations were in fact non-normal. The simulation data sets were generated with two test lengths (10 and 50 items) and four alternative true population distributions for the abilities: normal, bimodal, uniform, and chi-square. As expected, results showed that MML-Normal was …
Impact Of Different Item Location In Common-Item Test Equating, Luc Le
Impact Of Different Item Location In Common-Item Test Equating, Luc Le
Dr Luc Tu Le
This study used real data and simulation data to investigate the impacts of different item location in common-item test equating. The real data set included responses of about 150 000 students to a generic skills test from a university survey in Columbia in 2011, where each student was assigned randomly to one of four linked test forms. Each form consisted of two of three Critical Reasoning clusters and two of three Quantitative Reasoning clusters (20 items in each cluster). The results of an analysis using Item Response Theory clearly showed that items could become more difficult when located towards the …