At least that's what I learned in my physics undergrad days.

How so? Because all the students don't have the same background knowledge to build upon.

"As you learned in kindergarten..." was one of the favorite expressions of more than one of the instructors.

"To solve this, you complete the square and then ..." Only one guy in my class of ~ 30 knew to apply that trick to get the solution.

Lectures in college aren't intended to convey all the information you need to be able to answer all the questions on the exams. They're designed to stimulate thinking, to illustrate the types of things that you should be able to do, but they don't provide everything you need to do the work. They of necessity assume background knowledge, and the ability to apply that knowledge, and everyone (even good students) isn't going to have all the prerequisites. Everyone who pays attention and takes good notes and does the homework and works hard isn't going to do well in the class, because they don't have the same background. Lecturing isn't a "fair" way to teach - it's used because that's the way it's always been done.

There was a good show on public radio this afternoon on "expeditionary learning" and its history. There's a lot to recommend there. I can't find the particular show, but it seems to be part of this American Radioworks series.

Don't get me wrong. I'm not saying that college professors are cultural imperialists or something. I'm saying that the way college and university education is structured, it's designed (sometimes, like in many engineering and pre-medical schools, and in most PhD programs) to explicitly weed people out. Not to have everyone do as well as possible. The system is working as designed.

My $0.02.

Cheers,
Scott.