[levbrie]

To this point and the point below about undergrads and specialized knowledge: yes, you're absolutely right. I should not have said that undergrads don't have the specialized knowledge to teach. Plenty of undergrads make great TAs, and teaching assistants are a critical part of the learning process at most universities. What I should have said is that courses are not taught by (the role of the teacher is held by) undergraduates but by professors and graduate students, who are responsible for the planning, content, and instruction, and for the TAs that assist them. The only point I'm trying to make is that graduate students are given substantial full-time-equivalent jobs and that there place and role in the university ought to reflect this.