2025-03-27https://repository.covenantuniversity.edu.ng/handle/123456789/33661The study investigated the relationship of reliability and validity. Three psychological tests were administered on 268 Nigerian secondary school students spread over forms one, three and five. The tests were administered twice within a period of 6 weeks to allow for computation of test-retest reliability. The Cronhach’s r, the Split-half r, the Spearman Brown r and the Kuder-Richardson (KR 20) r were also derived. Content and Construct Validities were established through Z-test, t-test, factor analysis and correlation coefficient. It was concluded that when it is said that valid tests are reliable, it is the internal consistency reliability that is being referred to rather than the rest-retest reliability. In essence, not all valid tests will necessarily furnish indices of reliability on all types of reliability coefficients. Apart from raising some issues for further study, the finding has important implications for psychological tests’ development and usage.application/mswordBF PsychologyArticle