He is an extremely unorganized instructor. I had to teach myself the whole course through youtube videos. His tests are easy but sometimes poorly worded. He also enjoys giving epoll quizzes at random times throughout lectures, and often, it is on something he hasn't taught you yet. I feel bad for anyone who has to take this course with Duncan.

Switch to another professor

He's actually really underrated: Puts little to no pressure on students and encourages learning through your own ideas

Try to read your textbook before/ after each class, his slides are disorganized for sure, but they provide an accurate summary of what he plans to test you on. Office hours are GOATED, attend some, ask questions, and he'll do his best to explain everything to you even If you can't understand s***