Content validity refers to the extent to which a test or measurement accurately represents the concept it is intended to assess. It ensures that the items or questions included in the test cover all relevant aspects of the subject matter. For example, a math test should include questions on various topics like addition, subtraction, and multiplication to be considered valid. To establish content validity, experts in the field often review the test items to determine if they align with the intended construct. This process helps ensure that the test measures what it is supposed to measure, providing a more accurate evaluation of the subject being assessed.