Define validity. List by name the several kinds of test validity. Discuss each kind of validity by contrasting examples of tests that are low and high in it.

Validity refers to the extent to which a test measures what it claims to measure. In other words, it assesses whether a test is actually testing the construct or concept it is intended to measure. There are several kinds of test validity, including content validity, criterion-related validity, and construct validity.

1. Content validity: This type of validity refers to the extent to which a test measures the specific content or behavior it is supposed to measure. For example, a math test that includes questions on addition, subtraction, multiplication, and division would have high content validity for assessing overall math skills. On the other hand, a math test that only includes questions on addition would have low content validity as it does not cover the full range of math skills.

2. Criterion-related validity: This type of validity assesses whether a test is able to predict or correlate with a certain criterion or outcome. There are two subtypes of criterion-related validity: concurrent validity and predictive validity. Concurrent validity refers to the extent to which a test correlates with a criterion that is measured at the same time, while predictive validity refers to the extent to which a test predicts a future criterion. For example, a job performance test that accurately predicts future job performance would have high predictive validity, while a test that does not accurately predict job performance would have low predictive validity.

3. Construct validity: This type of validity assesses whether a test measures the theoretical construct or concept it is intended to measure. For example, a test that claims to measure intelligence should have high construct validity if it accurately measures intelligence and not other factors such as knowledge or memory. A test that claims to measure creativity should have high construct validity if it accurately measures creativity and not other factors such as intelligence or knowledge.

In summary, test validity is crucial for ensuring that tests accurately measure what they are intended to measure. Content validity ensures that a test measures the specific content or behavior it is supposed to measure, criterion-related validity assesses whether a test predicts or correlates with a certain criterion or outcome, and construct validity assesses whether a test measures the theoretical construct or concept it is intended to measure. By understanding and applying these different types of validity, test developers can ensure that their tests are reliable and accurate measures of the constructs they are intended to assess.