题组项目功能差异（DIF）检验方法的应用探索

篇章形式的阅读测验是一种典型的题组测验,在进行项目功能差异（DIF）检验时需要采用与之匹配的DIF检验方法.基于题组反应模型的DIF检验方法是真正能够处理题组效应的DIF检验方法,能够提供题组中每个项目的DIF效应测量,是题组DIF检验方法中较有理论优势的一种,主要使用的方法是Rasch题组DIF检验方法.该研究将Rasch题组DIF检验方法引入篇章阅读测验的DIF检验中,对某阅读成就测验进行题组DIF检验,结果显示,该测验在内容维度和能力维度的部分子维度上出现了具有显著DIF效应的项目,研究从测验公平的角度对该测验的进一步修改及编制提出了一定的建议.研究中进一步将Rasch题组DIF检验方法与基于传统Rasch模型的DIF检验方法以及变通的题组DIF检验方法的结果进行比较,研究结果体现了进行题组DIF检验的必要性与优越性.研究结果表明,在篇章阅读测验中,能够真正处理题组效应的题组DIF检验方法更加具有理论优势且对于阅读测验的编制与质量的提高具有更重要的意义.

The Application Study of Testlet DIF Procedure in Chinese Passage-based Reading Testing

With the development of test forms, testlet form test enjoys more and more popularity in Education and Psychological Testing. Passage - based form is a typical example of testlets, so the DIF procedures that are adopted must be able to handle the testlet effect properly. The tesflet model - based DIF detection approach is methodically sound,it provides the DIF effect of each item rather than the whole testlet. The Rasch Testlet Model is derived from the testlet model - based approach, DIF is taken into account by adding DIF pa- rameters into the Rasch testlet model. In this study,we first employed the Rasch Testlet Model to detect tesflet DIF in Chinese Passage - based reading testing. The bootstrap method is conducted to approximate the standard errors of the estimators for the DIF parameters so that the Wald statistic can be computed to test the null hypothesis of no DIF. The results indicated that some items on the content di- mension and the capacity dimension had significant DIF effect, and most of the DIF items favor of boys. We then gave advice on the fur- ther modification of the test. The second part of the study was a comparison study between the Rasch Testlet Model and the traditional Raseh Model and the alternative testlet DIF approach,the result displayed the necessity and advantage of the testlet model- based ap- proach. The results indicated that the tesflet model - based approach were more technically sound than the non - testlet DIF procedures and the alternative testlet DIF approach for passage - based testing.