Psychometric Evaluation of a Mathematics Achievement Test: Evidence of Content Validity and Internal Consistency from Senior Secondary Schools in Nigeria

Education is recognized the world over as the most potent and dynamic tool for national development and social change. Many subjects such as mathematics are studied at different levels of institutions in Nigeria for the realization of those goals of education. The teaching and learning of Mathematics therefore, becomes a vehicle for the delivery and attainment of these goals. Unfortunately, there has not been any known standard instrument in assessing students in Mathematics. We hereby developed and standardized Mathematics Achievement Test (MAT) in terms of evaluating its content validity and internal consistency in the Senior Secondary School System. An instrumentation research design was adopted for this study. Out of a population of 20,874 secondary school students, a sample of 400 was drawn for the study. The researcher developed a daft 60-item MAT from the curriculum as well as the blueprint. A pilot study was conducted guide the researcher for the main fieldwork and understand the population parameter estimations for the test. The content validity of the test was determined using goodness-of-fit test. Results showed a significant congruence between test blueprint and the actual test items. The test also yielded appreciably high internal consistency and stability indices. We concluded that the items of the MAT have a significant correspondence with the test blueprint and that the MAT has high internal consistency (90%).