LS4 is a bit complicated. I can't really say he's hard, but his questions are related to materials in textbook. Do problems in textbook, and go to his office hours and you should do fine.

LS4. Who gave this man his teaching credentials? HORRIBLE!

LS 4 -- Just finished my final in his LS4 class. Can I just say that I want to jump off a building right now? Diener is not a good lecturer, let alone a good professor -- he's awkward and loses his train of thought often. His problem sets (homework) are ridiculously hard, and his tests are even worse. I've gone to his office hours a couple times and I think I've come out more confused than I was before. Like someone said earlier, his answer key contains several mistakes and sometimes his written explanations just make me want to cry. GG GPA, it was nice knowing ya.

LS4: This guy can't teach. Period. His lecture slides (and lectures in general) were even more useless than the crappy textbook, and he can't explain the topics he teaches at all - since he teaches things that aren't even in the textbook, this is a problem ... a big problem. I left office hours feeling even more hopelessly confused than I did before going in. Homework is ridiculously hard, to the point where even HE couldn't do some of the problems he assigned when asked during office hours. And like someone previously mentioned, his answer keys are riddled with mistakes. So all in all - DON'T TAKE HIM! I mean he is nice and it does seem like he cares, but that doesn't change the fact that he belongs no where near a lecture hall teaching students.

Took LS4 with him. Not a great professor. His slides are pretty basic and don't convey the information needed to solve the hw problems. His answer keys for the problems contain multiple mistakes so checking my hw just made me even more confused. Not to mention the hw is practically impossible. Everyone I talked to had seemed to be just as lost as I was. Fortunately his tests are not as hard as the hw (although that is not saying much). Nothing in this class is connected. The slides are too simple, the hw is too hard, and the tests are somewhere inbetween in difficulty making it very hard to study for. If you're lucky he will put easier problems on the test; if you're unlucky he will destroy you with impossibly complicated problems

LS4: I took LS4 with this professor, and I especially liked his lecture slide.
Since he was not and experienced professor, his lecture is not as smooth as other professors,
but I really enjoyed the class.
Exam is a bit difficult, but as long as you like calculations and probability, you should be fine.