The three roles of assessment: gatekeeping, accountability, and instructional diagnosis

External assessment began as an imposed activity to provide quality control for a process. This gatekeeping role has a norm-referenced focus. A second role, ensuring accountability, emerged to judge the quality of education, an activity that has remained essentially norm-referenced. A third role, instructional diagnosis, is a recent phenomenon driven by the need to improve education and to provide educational, not political, justification. Traced from a measurement perspective, two requirements must be met for external assessment to yield instructionally diagnostic information: a reconceptualization of reliability, and development of more detailed and facilitative mechanisms for test …