http://www.rand.org/publications/documents/interneteval/

In response to concerns about variation in quality of health information on the Internet, the California HealthCare Foundation asked RAND to design and conduct a large study to that described and evaluated English and Spanish health information on the Internet. This study represents a major step forward in rigorous evaluation of web-based health information. (Au)The study addressed three questions: What type of condition-specific information do search engines identify, and how efficient are the engines as tools for locating health information?How comprehensive, accurate and current is the information presented on selected health Web sites?What level of literacy is required to understand the information provided by these sites?