You may well be right about the liberal arts vs engineering thing.
In liberal arts and humanities classes, attendance is generally not taken in large lecture classes. I have a friend who’s a history prof at UT Austin, and some of her lecture classes contain 400-500 students. There’s no way to take attendance in such a class, and if you don’t attend it is simply assmued that you will borrow the notes from someone else.
But, in the humanities, attendance is required whenever classes are held in smaller groups, especially when part or all of the class time is intended for discussion, rather than just the teacher lecturing.
So, while my friend lectures to 400-500 students for two hours a week, for another hour each week those 400-500 students split into groups of 15-20 and attend “sections” led by the professor or, more commonly, by advanced graduate students. Attendance is taken at such classes, because students are meant to do the reading for the week and contribute to class discussion.
Some classes are smaller seminar or mixed lecture/discussion classes. I’m teaching a class like that this semester, with 25 students. The class meets once a week for 2 hours and 45 minutes, and attendance is required of all students. Part of the time is taken up with me lecturing to the students, giving them background on the time period and providing some context within which they can place the reading that they do each week. The rest of the time is, or should be, taken up with class discussion, where the students and i talk about the week’s readings, their significance for the broader themes of the course and, quite often, their relevance to current political or social issues.
Attendance is required not only because we cover in class a lot of material that isn’t directly covered by the readings, but also because student participation in class discussion constitutes 25% of the students’ final grades. Part of any liberal arts or humanities course is helping students learn how to read the material closely, think carefully about it, and then communicate their ideas to other people—not only on paper, but orally also. Often, there are not necessarily “right” and “wrong” answers; instead, understanding is gained through a process of articulating your own position and listening to the arguments of others. I firmly believe that students understand the material better if they contribute to class discussion than if they just sit there and listen to me lecture.
You know, i’m surprised that you’re so surprised by this. After i left school, i did a year of a science degree before deciding to ditch it and go with the humanities. While my mathenatics, biology, chemistry and geology classes all had large lectures, each of those subjects also broke into smaller sections and labs, at which attendance was required. Many of my engineering friends had similar set-ups in their courses. I find it rather surprising (not to mention depressing) that every class you attended was apparently nothing more than a lecture hall filled with 600 students. That’s a pretty dull way to learn, IMO.