Membership in this blog is by invitation only. Please do not ask for an invitation: students are invited directly by Dr. Tufte as part of their class.
Memberships of students are maintained for several semesters after the class is over. Students are free to continue to post and comment after their class has finished.
Blogger has a limit on the number of authors who can be members of a blog. Eventually, students from past semesters get dropped. If you are dropped, and would like to renew your membership, contact Dr. Tufte directly.