The term achievement tests refers to tests designed to measure the knowledge, skills, and abilities attained by a test taker in a field, in a subject area, or in a content domain in which the test taker has received training or instruction. This entry first clarifies the difference between achievement tests and aptitude tests and introduces a brief history of achievement tests in the United States. It then describes the purposes of achievement tests, types of tests, and major steps in developing and administering achievement tests. The entry concludes with an overview of the benefits and limitations of achievement tests.