What does reliability refer to in standardized tests?

Reliability in standardized tests refers to the consistency and stability of test scores over time. This means that if a student takes the same test or a similar version of the test on different occasions, their scores should be relatively similar if the test is reliable. High reliability indicates that the test yields stable results, reflecting true differences in the trait being measured rather than random error or fluctuating conditions.

For example, if a test is designed to measure mathematics ability, a reliable test would yield approximately the same score if administered to the same individual multiple times under similar conditions. This demonstrates that the test consistently assesses what it intends to measure rather than being affected by outside factors. Hence, the emphasis on consistency is crucial in evaluating the trustworthiness of standardized assessments in educational settings.