It ranges in methodology from hardcore mathematical modeling to descriptive observations that use soft methods such as those of sociology. Biomedical informatics (BMI) is an extraordinarily broad discipline. It studies, models and designs data, processes, policies, organizations, and systems! In scale, it spans across genes, cells, tissues, organ systems, individual patients, populations, and the worlds medical ecology. No wonder it is difficult to find (or write) a text or reference book that encompasses the field. What distinguishes this field is its focus on a fundamentally computational approach to biomedical problems. Of course, every field in todays age of information uses computation as a tool,... Yet BMI has become a discipline, gradually moving from a variety of ad hoc collections of interdisciplinary programs towards a more formally defined specialty, recognized both as a subspecialty option for many fields of medicine and as a concentration in engineering programs?