Preface - Access to Knowledge Revisited.

OBJECTIVE: To review and update the Preface to the 1998 Yearbook of Medical Informatics, which had as its Special Topic "Health Informatics and the Internet".

METHOD: Assessment of the accuracy of predictions made in 1998 and consideration of key developments in informatics since that time.

RESULTS: Predictions made in 1998 were generally accurate regarding reduced dependence on keyboards, expansion of multimedia, medical data privacy policy development, impact of molecular biology on knowledge and treatment of neoplasms, and use of imaging and informatics to advance understanding of brain structure and function. Key developments since 1998 include the huge increase in publicly available electronic information; acknowledgement by leaders in government and science of the importance of biomedical informatics to societal goals for health, health care, and scientific discovery; the influence of the public in promoting clinical research transparency and free access to government-funded research results; the long-awaited arrival of electronic health records; and the "Cloud" as a 21st century reformulation of contracting out the computer center.

CONCLUSIONS: There are many challenging and important problems that deserve the attention of the informatics community. Informatics researchers will be best served by embracing a very broad definition of medical informatics and by promoting public understanding of the field.