Prieto Gerardo, Nieto Eloisa
Facultad de Psicologia, Universidad de Salamanca, Avenida de la Merced, 109-131, 37005 Salamanca, Spain,
J Appl Meas. 2014;15(2):176-88.
Research into Differential Item Functioning (DIF) has been an active research area in language testing (Ferne and Rupp, 2007). In this study we analyzed the DIF of two groups with different types of native language (927 Italians and 280 Asians) in a reading comprehension task forming part of an exam in Spanish as a foreign language. The Mantel-Haenszel (MH) and Rasch procedures for the detection of uniform and nonuniform DIF were used. The results reveal that the Rasch model and MH converge substantially on the results. Uniform DIF was detected in 6.6 per cent of the items and nonuniform DIF in 16.7 per cent. Half of the items affected by DIF favored the focal group (Asians) and the other half favored the reference group (Italians). The difference in test performance of the two groups did not appear to be affected by the elimination of items with DIF.
项目功能差异（DIF）研究一直是语言测试领域的一个活跃研究方向（费尔内和鲁普，2007）。在本研究中，我们分析了在外语西班牙语考试的阅读理解部分中，两组母语类型不同的群体（927名意大利人和280名亚洲人）的项目功能差异。我们采用了曼特尔 - 亨塞尔（MH）法和拉施程序来检测一致性和非一致性项目功能差异。结果显示，拉施模型和MH法在结果上基本一致。在6.6%的题目中检测到了一致性项目功能差异，在16.7%的题目中检测到了非一致性项目功能差异。受项目功能差异影响的题目中，有一半对重点群体（亚洲人）有利，另一半对参照群体（意大利人）有利。两组在测试表现上的差异似乎并未因剔除存在项目功能差异的题目而受到影响。
