We have decided to introduce our Questions and Answers section for the Archives with a question: "Why?" Our response is simple: "Because it should prove useful to readers." Although proof for this assertion is lacking, we have well-reasoned ideas, and they begin with how we all practice medicine.
To provide medical care, each physician will integrate a relatively large amount of information that is derived from three sources: physical examinations, laboratory studies, and history. This integration process takes into account the physician's own personal experience and medical knowledge that is derived from textbooks and "the literature." Ultimately, a differential diagnosis is developed and a program of further diagnostic studies and treatment developed. Despite heroic efforts, however, each physician's personal knowledge base remains considerably smaller than that contained in the literature, a problem that is certainly not new and certainly not helped by the relentless accumulation of new information, year after