Sahin Kursad Merve, Yalcin Seher
TED University, Turkey.
Ankara University, Turkey.
Appl Psychol Meas. 2024 Nov;48(7-8):303-322. doi: 10.1177/01466216241284295. Epub 2024 Sep 17.
This study provides an overview of the effect of differential item functioning (DIF) on measurement precision, test information function (TIF), and test effectiveness in computer adaptive tests (CATs). Simulated data for the study was produced and analyzed with the Rstudio. During the data generation process, item pool size, DIF type, DIF percentage, item selection method for CAT, and the test termination rules were considered changed conditions. Sample size and ability parameter distribution, Item Response Theory (IRT) model, DIF size, ability estimation method, test starting rule, and item usage frequency method regarding CAT conditions were considered fixed conditions. To examine the effect of DIF, measurement precision, TIF and test effectiveness were calculated. Results show DIF has negative effects on measurement precision, TIF, and test effectiveness. In particular, statistically significant effects of the percentage DIF items and DIF type are observed on measurement precision.
本研究概述了项目功能差异（DIF）对计算机自适应测试（CAT）中测量精度、测试信息函数（TIF）和测试有效性的影响。使用Rstudio生成并分析了该研究的模拟数据。在数据生成过程中，将题库大小、DIF类型、DIF百分比、CAT的项目选择方法以及测试终止规则视为变化条件。将样本大小和能力参数分布、项目反应理论（IRT）模型、DIF大小、能力估计方法、测试起始规则以及关于CAT条件的项目使用频率方法视为固定条件。为了检验DIF的影响，计算了测量精度、TIF和测试有效性。结果表明，DIF对测量精度、TIF和测试有效性有负面影响。特别是，观察到DIF项目百分比和DIF类型对测量精度有统计学上的显著影响。
