How I Use It
I test drove Genius with my own children at home as I am no longer in the classroom. All three of my middle school and high school age girls loved it! However, given that Genius is a repository for many, many song lyrics and articles, some content is explicit in nature. If there was a way to filter the site and comments so that explicit content was blocked, this site would be so much more valuable to teachers of children under the age of 18. Additionally, the requirement to provide an email address in order to register for an account is prohibitive and not compliant with federal regulations in order to use in a classroom.
While I love the concept of Genius and enjoyed playing on the site myself, I would not recommend using this site in a classroom with students under the age of 18. This definitely has some applications for college level students given that there are no issues with requiring an email address or need to protect as heavily from explicit content for that age group. As a supplementary assignment for my own children, I could more carefully regulate what they are annotating. Beware using this on a projector even for a group activity as some great annotators have very explicit commentators.
Final verdict - do NOT recommend for under 18.