Differential Item Functioning in Students Rating of Teaching Effectiveness Surveys in Higher Education According to Academic Disciplines: Data from a Saudi University

Abstract

This study explored academic discipline as a source of differential item functioning (DIF) in students' rating of teaching quality and effectiveness at higher education institutions. Data utilized in this study was collected by Imam Abudalruman Bin Faisal University -KSA. The total number of surveys analyzed for the purpose of this study is 36459 from three colleges: Education, Health, and Engineering. Using Extended Rasch model (Rating Scale Model), the results show that the instrument contains four DIF items. The content of these four items confirm the possibility of considering discipline as a source of DIF items in students evaluation of teaching in higher education. Moreover, the results of the current study show that removing DIF items from the instrument increases construct validity.