More than 60 percent of people in a Cisco Systems study this year said they often used the Internet to diagnose and manage health conditions. And they aren’t looking to YouTube, either. Wikipedia, the encyclopedia that’s one part reference work and another part chain letter, is the hot destination for students, scholars and patients alike.

Launched in 2001, Wikipedia contends that sharing information produces high-quality content. Anyone can edit, write or challenge the nearly 1.8 million articles contained on the site. Some schoolteachers have banned its use as a primary-info source; still, the social networking site Facebook.com has a group called “Wikipedia is helping me get through med school,” which has more than 4,000 members.  

How does Wikipedia’s AIDS info stack up? It’s clear and well sourced. In discussion rooms, users decide which articles should require a log-in for those who wish to edit. The “HIV” page is open to non-registered users; the “AIDS” page is protected. A Wikipedia study found that pages with the most user contributions have the highest quality. The “HIV” page had a comparatively high 1,184 edits last year. “AIDS” had 2,762—more than “HPV” (12), “breast cancer” (946) and “leukemia” (578) combined.