Gender-based Differential Item Functioning Analysis Of College English Placement Test Of Hunan University

This paper includes two sections of theory survey and application study. Theory survey part introduces some concepts relative to Item Bias,Item Impact,Item Response Theory and Differential Item Functioning, the present domestic and overseas research development in gender DIF of language testing, and some ordinary methods for DIF detection. In the application study part, gender DIF analysis based on the two forms of reading comprehension items of College English Placement Test of Hunan University (2007) was conducted using the one-parameter logistic model under IRT. The BILOG-MG software was used for DIF detection in this study. The results of this empirical study are as follows: For the reading comprehension items of Form 1 test, there were seven items demonstrate significant DIF,of which three items were against female students and four items were against male students. And there were three items showing moderate DIF; For the reading comprehension items of Form 2 test, there were seven items showing significant DIF, of which five items were against female students and two items were against male students. And there were two items showing moderate DIF. Most DIF items in this study are manifesting beneficial DIF except item 25 of both forms and item 30 of Form 2 test,which need to be revised or deleted. Possible sources of gender DIF were presented in this study. The results were as follows: 1. Reasoning items related to social sciences are beneficial for male students. 2. Items about grammar or closely related to the daily life are beneficial for female students. 3. Little difference was found between males and females in life and nature of science, or in environmental issues. 4. Interest differences, the difference in language communication ability and learning motivation are also factors that lead to gender DIF. In addition, based on these results, some suggestions were presented for future item development and item bank building for College English Placement Test of Hunan University.