What does test-retest reliability measure?

Test-retest reliability measures the consistency of scores over time, which is essential in evaluating the stability and dependability of a test. When an assessment is administered to the same group of individuals on two separate occasions, the scores obtained from both administrations are compared. A high correlation between the scores indicates that the test produces similar results across different time points, demonstrating that the test is a reliable measure of the construct it is designed to assess. This reliability is important for ensuring that test results are not significantly influenced by external factors or random errors, thereby providing educators and counselors with confidence in the test's outcomes for making informed decisions regarding student performance or needs.