I have been TAing the lectures “Computer Networks and Distributed Systems” and “Mathematics for CS students” for a term each and now I have gathered some experience with the exams. This is overall a very mixed experience.
Zeroth, most people do actually have some kind of understanding about the topics. But there is a long way from intuition towards understanding what is actually happening in the lecture and why it is happening the way it is happening. (Actually, this is a verification procedure for learning: If you know exactly what problems the lecture is solving and by what means, then you are most probably doing it right.)
First, some of the kids are pretty bad at reading and understanding. If the question is “What are the pros and cons of various methods of achieving X”, then the wrong approach is to tell me that a major downside is to implement X. Seriously? Let’s draw an analogy: A major disadvantage of owning a car is that you have to buy a car, and a major disadvantage of public transport is that you have to buy a ticket. Yeah, I’m not very impressed by this involved comparison, either.
Second, numbers and computation are a serious issue. This was evident in the networks exam, this is even more evident in the calculus exam, even if the students somehow managed to pass the initial “solve 50% of homework” filter. Integration seems to be like magic — sometimes it works, sometimes it does not, and most people seem to have no idea why. My hint “Solve 20 integrals and then you’ll know how” was not appreciated. In the networks exam, it was even worse, people failed at division of large numbers. (And it was awful to look at.)
Third, complex concepts are not easy to understand. (Captain Obvious reporting!) “This function is continuous and not continuous at the same time”, yeah, right. Sure, university lectures are not meant to be easy per se, but they are also not meant to be mandatory for everyone. And this is freshman material, not formal semantics from outer space. But this continues in the computer networks lecture, where some of the students write stuff like “Alice sends her private key to Bob”. If I were a columnist, I would write an awfully long lecture on how Facebook makes us disrespect privacy, but luckily I think that using “us” in the “us sinners” sense is a dirty rhetorical move, so I’ll just facepalm (or facedesk) one more time.
On the other hand, most people do seem to pass the exams, so it’s not all bad. But the aftertaste is pretty bitter.