质量评估的主要方法是对项目特征曲线、项目信息函数、测验信息函数、项目预测效度的分析和对项目偏差的检测。
The methods applied in data analysis are the analysis of item characteristic curve, item information function, test information function and item validity, as well as the checking of biased items.
项目功能差异(DIF)检验是保证测验公平性的需要，也是判别测验题目是否有偏差的重要步骤。
The detection of differential item functioning (dif) is crucial to ensuring the fairness of tests, which is an important approach to test if the item is biased or not.
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