[alasdair_]

The difference is that in Europe, you apply to take a specific subject at university, like Computer Science, and there are only so many spots available so that effectively caps the class sizes. You don't have a bunch of other people taking the class that are not working on that specific degree.

[vineyardlabs]

This is also the case in the US. The majority of college courses are limited to people within a given major and can't be taken by outside majors with limited exceptions.