The design, use and evaluation of today’s achievement tests are the result of a century of development and debate. Substantial change has occurred in three broad areas: the tests and measurement models crafted to assess student learning, the ideas of how to verify the technical quality of these tests, particularly validity, and the public policy directing the use of achievement tests to evaluate students or schools. These three aspects of achievement testing are intimately intertwined. At various points, the technical aspects of testing appeared to be paramount, advancing procedures designed to evaluate defensibility but limiting the uses to which a test could be put. At other times public policy has driven innovation in test design and changes in the meaning and use of results. Each perspective has also impacted the notion and implementation of equity practices in academic assessments.