Commercial sites are often difficult to evaluate because more and more often, companies are including educational information on portions of their sites. For example, the Duracell site includes a feature on the history of batteries. Usually, this means that the site has good information, but sometimes colleges and universities give Web space to students. Remember that the students may or may not check their facts when they put information up on the Web. Make sure that the individual cites their sources if you're considering to use the information in your research.
Universities offer Web space to their faculty members as well as to their students.
If you're studying a subject in which the individual whose page you're looking at is a prominent researcher, it's probably all right if she doesn't cite outside sources when she discusses the topic of her own expertise. This means that the site has something to do with providing internet-related service. Evaluating Web Sites.