Advances in cognitive, developmental, differential, and instructional psychology have recently become substantial enough to justify serious attention to the possibility of integrated instructional and assessment systems. New ways of conceptualizing and studying such systems are available. New technologies now make such systems more practicable. To capitalize on these scientific and technological advances, however, a substantial transformation of test research and development practice will be required. This document presents a long-range research and development agenda for the integration of instruction and assessment. Four projects under development are reviewed critically in the context of related research, and an agenda for future research and development activities is presented. Several conceptual questions are raised, and possible approaches to their solution are suggested to assist in later system development and evaluation. The paper uses relevant literature where possible, and identifies needs for further basic research, as well as research aimed at system design. The paper is intended mainly as a formative conceptual step, not a comprehensive literature review or a specific research and development proposal. In effect, the report reviews research and development issues in the literature rather than accumulated evidence from that literature.