ANALYSIS OF GENDER AND ETHNICITY-BASED DIFFERENTIAL ITEM FUNCTIONING IN WEST AFRICAN SENIOR SCHOOL CERTIFICATE MATHEMATICS EXAMINATION
The purpose of this study was to analyze gender and ethnicity-based differential item functioning in West African Senior School Certificate Mathematics examination. The study adopted instrumentation design. The area of study was composed of three states, namely Katsina, Imo and Oyo. The population was made up of all senior secondary school three students of 2012/2013 academic session in the three states totaling 128,779. Multistage sampling technique was used to draw a sample of 3,167 students. The instrument used in collecting data was Mathematics Multiple Choice Test prepared by the West African Examinations Council. The reliability of the instrument was established as .80. The data collected were analyzed using Differential Functioning of Items Test (DFIT) framework, which is based on Item Response Theory (IRT). Major findings of the study indicated that: (1) 74% of items function differentially between male and female, (2) 72% of items function differentially between ethnic Yoruba and Igbo, (3) 82% of items function differentially between Yoruba and Hausa, (4) 56% of items functions differentially for both Igbo and Hausa focal groups, (5) there was significant differential test functioning (DTF) between male and female, (6) there was significant DTF between Yoruba and Igbo, (7) there was significant DTF between Yoruba and Hausa. Other findings indicated that: (8) non significant DTF was obtained on basis of gender after deletion of 88% of items, (9) non significant DTF was obtained for Yoruba and Igbo after deletion of 44% of items, (10) non significant DTF was obtained for Yoruba and Hausa after deletion of 76% of items. On the basis of these findings, it rwas recommended that DIF analysis and judgmental review should be carried out on tests used in public examinations. Also, government should ensure that inclusion of members of examination bodies is based on qualified and competent professionals that belong to different groups.