|Educational Research (ISSN:2141-5161) Vol. 4(4), pp. 367-373, April, 2013
Copyright © 2013 International Research Journals
Full Length Research Paper
Differential item functioning method as an item bias indicator
* Uruemu Ogbebor and Adams Onuka
Institute of Education, University of Ibadan, Nigeria.
*Corresponding Author E-mail: email@example.com, Tel: +234-803-702-7063
Received December 8, 2012; Abstract
Differential item functioning is an approach that is widely used to find out items that are bias. This study investigated items that are bias using differential item functioning approach in relation to school type (private and public schools), school location (urban and rural schools) using National Examinations Council (NECO) Economics questions for 2010. The research design employed in this study was a comparative research type of design. The study sample comprised students in Delta State, Nigeria. Four hundred and forty seven (447) students were used. And the test contains 60 items which was administered to the students. Logistic regression was used to analysis the data. The research findings showed that out of sixty items in NECO economics questions 10 items were biased in relation to school type and 8 items in relation to school location. The implication of these findings is that NECO economics examinations questions have presences of differential item functioning (DIF). From the result of the findings, it was then recommended that test experts and developers should explore the use of DIF approach to detect biased items.
Keywords: Differential Item Functioning, Logistic Regression, Item Bias, Latent Trait.