A family recently came into my office and dumped a foot-high stack of papers on my desk. These, they explained, were pages they had printed from the World Wide Web that provided information on their child's rare genetic disease. What did I, a doctor and expert in the field, make of the reports? That night I spent eight hours reading through the pile, trying to separate quackery from relevant information. During that long evening, I also realized the extent of the difficulties ever more people face when they are trying to make important decisions about health care options.

Over the last few years the Internet has started to create an amazing challenge for medical providers. When people receive an unusual diagnosis, they frequently go to the Web to obtain all the information they can find. Every doctor I know has at least one anecdote about patients coming in with mounds of Web pages.