The Web is brimming with health sites, but how can you weed out the quackery? Use this checklist to evaluate health information you find online: 1. Check dates. Search for the most recent information you can find. 2. Check the source. Look for articles that refer to published medical research and have been reviewed by qualified professionals. 3. Be wary of commercial sites or personal testimonials. 4. Double-check what you find. Visit several health sites and compare the information they offer. 5. Talk with your doctor before you follow any medical advice you find online.