Psychometric Properties: Difficulty Index Deferential Between WAEC and NECO Computer Studies Examination Items in Kaduna State, Nigeria

Abstract

The paper assessed difficulty index as psychometric properties of West African Examination Council (WAEC) and National Examination Council (NECO) Computer Studies objective test items of 2019 using Item Response Theory (IRT). There has been a continuous misconception of the standard of WAEC being superior to NECO based on the scope of coverage and duration of operations. This paper investigated the difficulty index of items in the two examination’s multiple test on Computer Studies conducted in 2019 among final year secondary school students in Kaduna state. The instruments were administered to the 322 sampled students in 12 public secondary schools selected for the study under similar conditions as given by the two examination bodies. Fifty objective questions were assessed for WAEC while 60 questions were assessed for NECO. The scores were graded for item difficulty index and subjected to statistical analysis using the Statistical Package for the Social Sciences (SPSS, IBM version 26. The scores were then categorized into simple (0.7 – 0.9), moderate (0.4-0.6) and difficult (0.0 – 0.3). The chi-square procedure was used to determine differences in difficulty index associated with the different examination bodies. Findings revealed that, of the total items involved in the assessment, 61.7% of NECO items and 58.0% of WAEC items were of moderate levels respectively. No significant difference was observed in the difficulty index of the two examinations’ objective test questions in Computer studies (p > 0.05). There distraction index was not significantly different. The study therefore recommended among others that the present standard of the examinations conducted by the Public Examination Bodies in Nigeria should be sustained and improved upon by subjecting the test items to more regular and rigorous item analysis procedures and selection of items that fall within the acceptable range of psychometric characteristics