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• Main Author: 林家瑜
• Other Authors: 李信宏
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/ru4ap3

碩士 === 國立彰化師範大學 === 數學系 === 106 === Differential item functioning (DIF) is one of the important indices on detecting item’s fairness. This study applies sign test to detect nonuniform DIF generated by a cognitive diagnostic DINA model. DINA model separates examinees into masters and non-masters. Nonuniform DIF is found to occur when an item is beneficial to both masters from the reference group and non-masters from the focal group. It’s implied that the directions of the influence of DIF are not the same. A nonparametric sign test based on the odds ratios of item responses of the focal and reference groups is used to investigate the nonuniform DIF. The factors of simulation study contain the correlation of attributes, item parameters, sample sizes and the amount of DIF. The average type I error rates are approximated to the significant level of 0.05. Meanwhile, the powers rise significantly as the sample size and the amount of DIF increase. When the required attributes of the item increase, the differences between two groups cannot be well identified and the results of the sign test are often viewed as uniform DIF instead of nonuniform DIF.