Abstract

 The study examined the differential itemfunctioning ofNational Business-Technical Examinations Board (NABTEB) Agricultural Science multiple choice test iietns (2015-2017) in South East Zone. The study adopted Descriptive Survey research design and Ex-Post-Facto research design. Two research questions and two null hypotheses were raised and formulated respectively that guided the study. The population ofthe study was 10, 194 Agricultural Science students which includes 5043 males and 5151 females 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 usedforthe study. The instrument usedfor data collection wasNABTEBAgricultural Science constructed in 2015-2017. The instrument wasre-validated by three experts, twofrom Measurement and Evaluation and onefrom the Department ofAgricultural Extension Education; allfrom Michael Okpara University’ ofAgriculture, Umudike. The data obtainedwas analysed usingKuder Richardson Formular 20 with reliability’ indices of0.76. Data obtainedfor the study were analyzed using the Scheuneman modified Chi-square statistic to analyse all the research questions and chi-square test statistic was employed in testing the null hypotheses. Results showed that Agricultural science multiple-choice test items used in NABTEB 2015-2017, contain test items that significantlyfunctioned differentiallyfor testees on the basis ofgender and school location. That there was no significant difference in thepercentage ofthe number of items thatfunctioneddifferentially bygenderinfavour ofmales and those infavour of females in the 2015-2017 NABTEB Agricultural Science multiple choice test examination. It was thus recommended among others that test item writersforpublic examinationsshould be encouraged to use simple English language. This willreduce the tendency of introducing additional task into the measurement ofAgricultural Science ability’