I know that students really don't enjoy taking exams- neither did I for that matter, but they are a necessary evil in universities- especially in large, lecture-based classes. I do my best to weight them as low as I reasonably can, because I do not feel comfortable evaluating students based solely on exams. Some students really seem to understand the material, they come to every class, and then they completely blow it on tests. There are a variety of reasons, but whatever they are, it sucks for everyone involved.
Writing exams is also no picnic. It's difficult to make sure that they reflect what was covered in class and readings, are not unreasonably difficult, and can be completed in the time given. I have only been teaching full-time for a few years, but feel that I write decent exams. Students often complain that they are too difficult, but I always have some students that earn 'A's, too. So, it's a dilemma and certainly NOT my favorite part of teaching.
I felt this was an appropriate post, since I just finished revising an exam for my large, freshman-level class. I hope they don't hate it! It really isn't my goal to fail to anyone- unless, of course, they never show up to class and don't do the work!