ANALYSIS OF DIFFERENTIAL ITEM FUNCTIONING OF NATIONAL EXAMINATIONS COUNCIL AGRICULTURAL SCIENCE MULTIPLE CHOICE TEST ITEMS IN SOUTH EAST, NIGERIA

The study examined the differential item functioning of National Examinations Council (NECO) Agricultural Science multiple choice test items (2015-2017) in South East Zone. The study adopted descriptive survey research design and ex-Post-Facto research design. Two null hypotheses were formulated and test in the study. The population of the study consisted of 10, 194 Agricultural Science students. Sample size of 728 Agricultural Science Senior Secondary School students (SSS III) were proportionately drawn from the 72 selected secondary schools that constituted the sample size of the study. A multi-stage sampling technique was used for the study. The instrument used for data collection was NECO paper III questions constructed in 2015-2017.The instrument was re-validated by experts in Educational Measurement and Evaluation and Agricultural Extension Education. The data obtained was analysed using Kuder Richardson Formular 20 with reliability indices of 0.76. Data obtained for the study were analyzed using the Scheuneman modified Chi-square statistic to analyze all the research questions and chi-square statistic was employed in testing the null hypotheses. Results showed that that Agricultural Science multiple-choice test items used in NECO 2015-2017, contain test items that significantlyfunctioned differentially for testees on the basis of gender and that there was no significant difference between male and female students on the percentage of items which functioned differentially in the 2015-2017 NECO Agricultural Science multiple choice test examination. It was thus recommended among others that test experts and developers should consider the use of Scheuneman modified chi-square in determining differential item functioning.