Professor Gordon argues for a significant reorientation in the focus and impact of assessment in education. For the types of assessment activities that he advocates to prosper and positively impact education, serious attention must be paid to two important topics: (1) the conceptual underpinnings of the assessment practices we develop and use to support learning and instruction, and (2) the arguments and evidence we establish for their validity given the intended interpretive use. Such a focus highlights fundamental concepts that have long existed in the broader assessment literature -- carefully defining and operationalizing our constructs and then validating the assessments of those constructs. What differs now are the conceptual frameworks, briefly outlined here, that can and must be used to guide both aspects of such work. [For "Toward Assessment in the Service of Learning" by Edmund W. Gordon, see EJ1266797.]