<p>Most of my professors have been very approachable and helpful. They always have office hours, but if you can't make the scheduled time, you can usually set up an appointment at another time. Last semester, two of my professors always answered questions over e-mail and they were always very helpful. My professors this semester are the same way. For the larger lecture classes, it will usually be harder to communicate with them directly, but they always have office hours if you are interested. </p>
<p>Also, the TA's (mostly for discussion sections) can be good and helpful, but some classes won't have any TA's. Overall, my experience with the Duke faculty has been very positive.</p>