DIFFERENTIAL ITEM FUNCTIONING OF NATIONAL EXAMINATIONS COUNCIL (NECO) AGRICULTURAL SCIENCE QUESTIONS FOR 2015

Kelechi Joshua Princewill Ihechu & Adolphus Onuabuchi Madu

                                                      College of Education

Michael Okpara University of Agriculture

Umudike, Abia State, Nigeria

Email: donsignor4ray@yahoo.com & Adolphus4god@yahoo.com

Abstract

Differential item functioning is meant to find out items that are biased. This study investigated items that are functioning differently in relation to school type (private and public schools), school location (urban and rural schools) using National Examinations Council (NECO) Agricultural Science questions for 2015. The research design employed in this study was a comparative research type of design. The study sample comprised students in Imo 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 analyse the data. The research findings showed that out of sixty items in NECO Agricultural Science questions 11 items were biased in relation to school type and 9 items in relation to school location. The implication of these findings is that NECO Agricultural Science examinations questions have items that are biased along school type and location dimensions. From the result of the findings, it was then recommended that test experts and developers should explore the use of logistic regression in detecting items that are biased before administering them.

Keywords: Differential Item Functioning, Logistic Regression, Item Biased, Latent Trait