Which type of validity indicates whether a test appears to assess what it aims to assess?

Content validity refers to the degree to which a test adequately covers the construct or skill it is intended to measure. It is concerned with the alignment between the test items and the specific content or domain of knowledge relevant to the assessment. In essence, if a test is designed to measure knowledge in a particular subject area, content validity ensures that the questions truly represent that subject matter and cover all necessary aspects.

For instance, if a math test is supposed to measure students' understanding of algebra, content validity would ensure that the test questions reflect the key concepts and problem-solving skills related to algebra, rather than veering into unrelated topics like geometry or statistics. This kind of validity is often evaluated through expert judgment, ensuring that test content is representative of the subject area.

In contrast, construct validity focuses on how well a test measures the theoretical construct it is intended to evaluate, while criterion-related validity (both predictive and concurrent) examines how a test aligns with other measures or outcomes. External validity relates to the generalizability of the test results across different settings or populations. Therefore, while these other types of validity are important, they do not specifically address the appearance and coverage of the content within the assessment framework as content validity does.