An investigation of item bias of English test in 2016 year undergraduate placement exam

The purpose of this study is to determine whether items of English test of Undergraduate Placement Exam (UPE) in 2016 include differential item functioning (DIF) and differential bundle functioning (DBF) in terms of gender and school type and examine the possible sources of bias of DIF items. Mantel Haenszel (MH), Simultaneous Item Bias Test (SIBTEST) and Multiple Indicator and Multiple Causes (MIMIC) methods were used for DIF analyses. DBF analyses were conducted by MIMIC and SIBTEST methods. Expert opinions were consulted to determine the reasons of bias in items showing DIF. Data set of the study consisted of responses of 59818 candidates to 2016 UPE English test. As a result of the analyses carried out on 60 items in English test, it was seen that one item in translation subtest contained DIF in favor of male candidates. For school types, schools that the candidates graduated were gathered under four headings as vocational high school, Anatolian high school, religious vocational high school and private high school. In school type based analyses, it was concluded that there were nine DIF items in vocabulary and grammar knowledge subtest, six DIF items in reading comprehension subtest and four DIF items in translation subtest. Experts stated that one item containing DIF by gender was not biased and evidence of bias was found in thirteen of nineteen items that included DIF by school type. According to DBF analyses, it was found that some item bundles contained DBF with respect to gender and school type. As a result of this research, it was discovered that there were differences with regard to the number of DIF items identified by three methods and the level of DIF that the items included; however, methods were consistent in detecting uniform DIF. The reason why the number of DIF items by school type was higher than the number of DIF items by gender was considered to be the serious gap between schools. Keywords: Undergraduate placement exam, differential item functioning, differential bundle functioning, item bias, MIMIC