<p>i was looking through the catalog, and some classes say that they have to be taken in sequence. yet, some classes can be taken as 2 or 3 sequence classes (the description says they can be taken for instance in the autumn and winter or winter and spring). Do sequences mean that you have to start with the the first class, or can you start with the second one? or does it just mean you can't take them backwards?</p>
<p>With very few exceptions (some Civ classes will let you break the sequence), you need to take classes in sequence starting starting with the first class until the last class. This is mainly done to help you out- it would totally suck to take the 3rd quarter of a class that assumes you know two other quarters of material.
The exception to this is courses in sequence that don't technically build on eachother- you can get away with taking the 2nd and 3rd quarters of some Civ courses without the first- or instances when you already know the material for the first few quarters and can skip ahead, like in a language or some calculus classes.</p>
<p>Another exception is phy sci. If you take, for example, Natural Hazards and Global Warming, it doesn't matter which class you take first. You can even do them in different years.</p>
<p>If classes don't have to be taken in sequence the catalog usually says so. HUM, SOSC and CIV must be taken in sequence (but some CIV you can do classes 1 and 2 or 2 and 3 out of a 3 class sequence).</p>