What term refers to the accuracy with which a test fulfills the function for which it was designed?

The term that refers to the accuracy with which a test fulfills the function for which it was designed is validity. Validity assesses whether a test measures what it is intended to measure. For example, if a test is designed to assess mathematical skills, validity determines how well the test actually evaluates those skills, rather than other unrelated areas.

In psychological and educational assessments, validity is crucial because it ensures that the inferences made from test scores are meaningful and relevant. High validity implies that the results can be confidently used for the purpose intended, such as making decisions about an individual's abilities or knowledge in a specific area.

Reliability, on the other hand, pertains to the consistency of test results over time or across different groups; it does not address whether the test measures the intended construct accurately. Consistency could refer to various aspects, but it generally relates more to reliability. Objectivity refers to the degree to which assessment results are free from bias, which, although important, does not specifically indicate how well a test measures its intended purpose.