Why are Wash U classes 3 units and not 4

<p>I've noticed that most classes are only 3 units. As I understand it in a lot of colleges, semester classes are usually 4 units.</p>

<p>From what my friends at other schools have said, they're typically 3.</p>

<p>My physics (gen. phys) is 4, and chem is 5 with the lab included in that.</p>

<p>I heard some college faculty mention that: the idea is that you are able to take five 3-credit courses instead of four 4-credit courses per semester (roughly) giving you a little more choice in things, which is something the college considers important for a "liberal arts education." It has seemed fine to me so far, the number of credits per class isn't a huge deal.</p>

<p>Actually, I thought 3 units was standard for a lecture class on a semester based system - a lab section can add an additional 1 credit. A lecture class meets either MWF for 1 hour each day, or T-Th for 1.5 hours each. What colleges have non-lab classes at 4 units ??</p>