[ptero]

Are you serious? Can you share the school and department? This is an honest question -- I always thought 4-5 lecture or classroom hours was normal. That's what I had and that's what my friends had. Most of us never even used graders assigned as grading duties were light and it would often be more trouble to explain how you wanted it graded anyhow.

I have never heard of a 20 hour TA load. Again, just wondering.

[munin]

Every CS department I have ever heard of has a 20 hour TA load as standard.

[_ptgt]

I was in a stats department for grad school. My assistantship load was nominally 20 hours, but I managed to teach a course as a GI in probably ~10 hours/week (doing my own grading). It took more time commitment if it was my first time teaching the course, and when I had to write/grade exams.

I'd imagine my experience wasn't an uncommon one.

[ptero]

20 hours of work is pretty extreme and I suspect cuts down on your mental ability to do research (you have to take classes, too). I suspect the department usually has to say it is a 20 hr/wk position (probably so student gets free tuition), but the actual work is often less -- my friend who went to U of Maryland for PhD in CS had a similar experience to mine -- 7-10 hours a week of actual work at most.

This is just a couple of data points, though. Maybe we were just lucky.