This study aimed to validate the Social Studies Achievement Test developed by Ekiti state ministry of education for Junior Secondary Three (JS3) students. It was guided by two research questions and adopted an instrumentation research design. The study population consisted of 99,840 JS3 Social Studies students in public secondary schools across the state, from which a sample of 650 students was selected. The instrument validated was the Social Studies Achievement Test for JS3 students developed byEkiti state ministry of education Its reliability coefficient was determined to be 0.76 using the Kuder-Richardson Formula 20 (KR-20). Initially, 70 items were validated; however, following validation These items were further analyzed to determine their difficulty levels, discrimination indices, and the effectiveness of distracters. Findings revealed that 58 items had acceptable difficulty indices, all 70 items demonstrated positive discrimination indices, and all items functioned effectively in terms of distractors. Mean and standard deviation were used to address the fifth research question, showing that the test items aligned with the core curriculum. Overall, the developed Social Studies Achievement Test exhibited strong psychometric properties, particularly in terms of item difficulty, discrimination, and reliability. Based on these findings, it was recommended that the test could serve as a model for constructing achievement tests in Social Studies and other subjects.
Keywords: Achievement, Reliability, Social Studies, Test, Validation
