Although the radical concept of understanding the effect of medical and operative treatment on patient function emanated from Codman3 more than sixty years ago, the orthopaedic community has been actively engaged in the outcomes movement for only the last twelve to fifteen years. Under the leadership of such individuals as Gartland and Sledge, we collectively became aware of the deficiencies apparent in our literature, which had resulted in a less-than-solid foundation on which to make treatment recommendations to patients4,5,9. The technique of small-area analysis pioneered by Wennberg and others revealed the effects of this lack of a solid foundation10,11. Our orthopaedic community is now actively involved in remedying this problem. For eight years, the Outcomes Committee of the American Academy of Orthopaedic Surgeons has provided annual courses on the techniques used in the field of outcomes assessment. We have devoted substantial resources toward providing validated questionnaires and the software to use them. We have done much of the political groundwork to establish broad acceptance for a unified approach to the collection and use of data. We have come a long way indeed. Despite these accomplishments, two questions remain: how should these data be used, and who should be involved in collecting them? The resources involved in obtaining data are substantial; however, health-care payers have little interest in funding these activities. Therefore, we believe that a timely review of the current status of data collection, future opportunities, and the challenges to be overcome is appropriate. We begin with a review of the basic principles involved in the selection of outcomes-measurement instruments and then offer an overview of the American Academy of Orthopaedic Surgeons' involvement in providing the critical resources for the orthopaedic community. Next follows a thoughtful review of the …