Society must answer questions about health information technology applications, or telehealth, that lead to the best allocation of resources for maintaining and improving the health status of our population. These questions deal with the adoption and deployment of telehealth for improving the health and well-being of the members of society, compared with alternative means. From the less than overwhelming response to the "build it and they will come approach, we clearly have insufficient evidence of the medical effectiveness, cost effectiveness, and patient :and provider satisfaction with telehealth solutions. The Agency for Health Ch-re policy and Research (AHCPR) I is a federal research agency that supports research to find out what is effective in improving the quality; of and access to heath services in the community, what is the impact on patient outcomes, and what is the cost of obtaining those outcomes. Telehealth decision makers need studies of telehealth technologies that focus on specific clinical conditions in narrowly concentrated applications and that use scientific methods to compare outcomes and treatment costs for patients and physicians who do and those who do not receive telehealth services under controlled circumstances. AHCPR-funded studies are presented as examples of methods of scientific investigation into the use and acceptance of computerized decision support and telehealth services.