Which definition describes whether a test measures what it claims to measure?

The correct definition that describes whether a test measures what it claims to measure is validity. Validity refers to the extent to which a test accurately assesses the specific concept or trait it is intended to measure. For example, if a test is designed to evaluate students' mathematical abilities, its validity would determine if it effectively measures those skills rather than other areas, such as reading comprehension or general intelligence.

In educational assessments, establishing validity is crucial as it impacts the interpretations and decisions made based on test results. A valid test ensures that conclusions drawn from the results are meaningful and applicable to the construct being assessed.

Other concepts, like reliability, focus on the consistency of a test's results over repeated administrations, while generalizability pertains to the degree to which findings can be applied to settings beyond those in which the test was conducted. Comparative analysis involves examining similarities and differences between tests or groups but does not directly address the fundamental measurement accuracy a test claims to provide. Therefore, validity is central to the integrity and usefulness of any assessment tool in measuring specific constructs.